The required volume of 0.0500 M sodium hydroxide that should be added to 250 ml of 0.100 M HCOOH to obtain a solution with a pH of 4.50 is: 10.5 ml.
To solve this problem, we can use the equation for the reaction between HCOOH and NaOH. The balanced chemical equation is: HCOOH + NaOH → HCOONa + H₂O
From this, we can see that one mole of HCOOH reacts with one mole of NaOH to form one mole of HCOONa and one mole of water. We can also write the equation for the ionization of HCOOH: HCOOH + H₂O ⇌ H₃O+ + HCOO-
At pH = 4.50, the concentration of hydronium ions is 3.16 x 10⁻⁵ M. Using this value, we can solve for the concentration of formate ions:
[H₃O+] = [HCOO-]Ka = [H₃O+][HCOO-]/[HCOOH]
Substituting the values gives: Ka = (3.16 x 10⁻⁵)2 / (0.100 - x)x = 0.00227 M
where x is the amount of HCOOH that reacts with NaOH.
Substituting the values gives:
(0.00227)(V1) = (0.100)(0.250 - x)V1 = (0.100)(0.250 - x) / 0.00227V1 = 10.5 - 4.63x
The pH of the solution is given as 4.50. This means that the concentration of hydronium ions is 3.16 x 10⁻⁵5 M. Using this value, we can solve for the concentration of formate ions:
[H₃O+] = [HCOO-]Ka = [H₃O+][HCOO-]/[HCOOH]
Since one mole of HCOOH reacts with one mole of NaOH, the amount of NaOH that is required to react with x moles of HCOOH is also x moles. Therefore, the concentration of NaOH that is required is also 0.00227 M. The volume of NaOH that is required can be calculated using the following equation: M1V1 = M2V2
where M1 is the concentration of NaOH, V1 is the volume of NaOH, M2 is the concentration of HCOOH, and V2 is the volume of HCOOH.
Substituting the values gives[tex](0.00227)(V1) = (0.100)(0.250 - x)V1 = (0.100)(0.250 - x) / 0.00227V1 = 10.5 - 4.63x[/tex]
Since x = 0.00227 M, V1 can be calculated as: [tex]V1 = 10.5 - (4.63)(0.00227) = 10.5 - 0.0105 = 10.5 mL[/tex]
Therefore, the volume of 0.0500 M sodium hydroxide that should be added to 250 mL of 0.100 M HCOOH to obtain a solution with a pH of 4.50 is 10.5 mL.
To know more about sodium hydroxide refer here:
https://brainly.com/question/29327783#
#SPJ11
Question at position 1
What is the pressure of gas if 2. 89-g of CO2 sublimates in a 9. 60-L container at 255. 22K
The pressure of the gas in the container if 2. 89-g of CO2 sublimates in a 9. 60-L container at 255. 22K is 0.1431 atm. This is calculated using ideal gas equation.
Mass of solid CO2 = 2.89 gm
Volume of container, V = 9.60 L
Temperature, T = 255.22 K
We can calculate the number of moles of CO2 using the expression,
No. of moles = mass / molar mass
Molar mass of CO2 is 44.01g/ mole.
No. of moles, n =2.89 g / 44.01 g/mole
= 0.0656 mole
We can use here the ideal gas equation,
PV = n RT
we have the value of the R constant which is [0.08206 L. atm. K-1 mol-1]
P = n RT / V
P = 0.0656 mole x 0.08206 L. atm. K-1 mol-1 x 255.22 K / 9.60 L
= 0.1431 atm.
So the pressure of the gas in the container is 0.1431 atm.
To learn more about Ideal gas equation
https://brainly.com/question/27870704
#SPJ4
which of the methods below can be used to prevent the oxidation of an iron object? 1) painting the object 2) attaching a sacrificial electrode made of zinc 3) submerging the object in water
One method for preventing oxidation of the object is painting it with iron material.
How can iron objects be kept from rusting?Oiling, painting, or lubricating By applying oil, grease, or paint, the surface is provided a waterproof coating that keeps moisture and oxygen from coming into direct contact with the iron item. Hence, rusting is prevented.
What kind of paint is applied to iron?Oil-based metal paints are the best choice for outside work, according to paint manufactured with oil. Very durable and frequently easier to remove is oil paint. Primer is not necessary when using an oil-based product, although it will produce a smoother finish. Oil-based paints are often more costly.
To know more about oxidation visit:-
https://brainly.com/question/9496279
#SPJ1
2 nh3 3 cuo g 3 cu n2 3 h2o in the above equation how many moles of water can be made when 84 moles of nh3 are consumed?
By using the stoichiometric ratio of the equation 2 NH3 + 3 CuO → 3 Cu + N2 + 3 H2O. when 84 moles of NH3 are consumed, 504 moles of H2O can be made.
Given the equation: 2 NH3 + 3 CuO → 3 Cu + N2 + 3 H2O
If 84 moles of NH3 are consumed, then:
Step 1:
Calculate the number of moles of CuO required for the reaction.
Using the stoichiometric ratio of the equation, the number of moles of CuO required for the reaction is (2 x 84 moles NH3) = 168 moles CuO.
Step 2:
Calculate the number of moles of H2O formed.
Using the stoichiometric ratio of the equation, the number of moles of H2O formed in the reaction is (3 x 168 moles CuO) = 504 moles H2O.
Therefore, when 84 moles of NH3 are consumed, 504 moles of H2O can be made.
For more such questions on stoichiometric ratio , Visit:
https://brainly.com/question/9413308
#SPJ11
a metal will be placed in fire and an electron will absorb enough energy to be promoted to a higher energy state. what do we call this higher energy state?
When a metal is placed in the fire and an electron absorbs enough energy to be promoted to a higher energy state, this higher energy state is referred to as the excited state.
An excited state is a state of a molecule or atom in which it has absorbed sufficient energy to move an electron from its current orbital to a higher orbital. This state is referred to as the excited state, and the electron that has been elevated to a higher energy level is said to be in an excited state.
The reason behind the electron's promotion to a higher energy state when a metal is placed in fire is that the heat causes the electrons to absorb energy, which causes them to move to a higher energy state. When electrons move to higher energy states, they release energy in the form of light, heat, or other radiation.
Learn more about electron https://brainly.com/question/26084288
#SPJ11
calculate the enthalpy change when 5 g of zinc metal is heated from 100oc to the point where the entire sample is melted. (the heat of fusion for zinc is 112.4 j/g and its specific heat capacity is 0.388 j/goc.)
The enthalpy change when 5 g of zinc metal is heated from 100oc to the point where the entire sample is melted having the heat of fusion for zinc is 112.4 j/g and its specific heat capacity is 0.388 is 581.4 J.
specific heat capacity is 0.388 j-1c-1 .
The specific heat capacity can be defined as the quantity of heat (J) absorbed per unit mass (kg) of the material when its temperature increases 1 K.
The heat of fusion for zinc is 112.4 j-1.
The expression for Heat energy is,
= mcΔT+mL
where, m = mass of water
c = specific heat capacity of water
L = specific latent heat of fusion of ice
ΔT = change in temperature
Heat energy can be explained as a result of the movement of tiny particles called atoms, molecules or ions in solids, liquids and gases. It can be transferred from one object to another. The transfer or flow of heat energy due to the difference in temperature between the two objects is called heat.
Putting all the values in the expression of heat energy, we get,
= 0.5 g * 0.388 * 100 + 5 * 112.4
= 19.4 + 562
= 581.4 J
To learn more about specific heat capacity
https://brainly.com/question/27991746
#SPJ4
how many possible orientations are there with which co and o2 can collide, and how many of those orientations can result in a successful reaction?
Possible orientations with which CO and O₂ can collide are: 8, and out of which orientations that can result in a successful reaction are: 4
CO-O2 Collision Orientations:
1. Linear - CO and O₂ are aligned in a straight line
2. Propeller - CO and O₂ are at 90° angle
3. Clapping - CO and O₂ move parallel to each other, 180° out of phase
4. Disrotatory - CO and O₂ move parallel, same phase
5. Conrotatory - CO and O₂ move parallel, opposite phase
6. Tumbling - CO and O₂ are at an angle and tumble in an elliptical path
7. Twisting - CO and O₂ at a 60° angle, move opposite to each other
8. Vibration - CO and O₂ oscillate
Successful Reactions:
1. Linear
2. Propeller
3. Clapping
4. Disrotatory
These four orientations can result in a successful reaction because the molecules are in the correct orientation for the electron orbitals to align, allowing for the electron transfer needed for the reaction to occur.
In conclusion, there are 8 possible orientations with which CO and O₂ can collide, and out of those 8, only 4 orientations result in a successful reaction.
To know more about orientations refer here:
https://brainly.com/question/4474232#
#SPJ11
if 75.0 grams of carbonic acid are sealed in a 2.00 l soda bottle at room temperature (298.15 k) and decompose completely via the equation below, what would be the final pressure of carbon dioxide (in atm) assuming it had the full 2.00 l in which to expand?
The final pressure of carbon dioxide in the soda bottle, assuming it had the full 2.00 L in which to expand, is 1.20 atm.
The equation for the decomposition of carbonic acid is: H2CO3 → H2O + CO2.
When 75.0 g of carbonic acid is sealed in a 2.00 L soda bottle at room temperature (298.15 K), the decomposition reaction will occur and the carbon dioxide (CO2) will expand to fill the available space in the bottle.
The final pressure of carbon dioxide (in atm), the ideal gas law equation:
PV = nRT, where P is the pressure, V is the volume, n is the number of moles, R is the universal gas constant, and T is the temperature.
Since we know the initial amount of carbonic acid (75.0 g), the number of moles present: n = (75.0 g H2CO3) / (84.01 g/mol), giving us a value of 0.894 moles.
The volume of the bottle (2.00 L) and the temperature (298.15 K). Thus, we can plug these values into the ideal gas law equation to calculate the final pressure of carbon dioxide:
P = (0.894 mol CO2) (0.08206 L*atm/K*mol) (298.15 K) / (2.00 L), which gives us a pressure of 1.20 atm.
Therefore, the final pressure of carbon dioxide in the soda bottle, assuming it had the full 2.00 L in which to expand, is 1.20 atm.
to know more about carbon dioxide refer here:
https://brainly.com/question/13528931#
#SPJ11
calculate the volume in ml of a 6 m solution of hcl stock solution required to make 250 ml of 50 mm hcl?
The volume in ml of a 6 m solution of hcl stock solution required to make 250 ml of 50 mm hcl is: 20.8 ml.
To calculate the volume of a 6 M HCl stock solution required to make 250 ml of 50 mM HCl, use the following equation:
volume of stock solution (ml) = (desired concentration (mM) x volume of desired solution (ml)) / stock solution concentration (M).
Therefore, in this case, volume of stock solution (ml) = (50 mM x 250 ml) / 6 M = 20.8 ml. In other words, 20.8 ml of a 6 M HCl stock solution is required to make 250 ml of 50 mM HCl. This is because the number of moles (the amount of HCl molecules) in the solution must remain constant.
Increasing the volume of the solution by dilution means that the concentration (the amount of HCl molecules per ml of solution) must be decreased, and thus the amount of HCl stock solution must be increased.
To know more about HCl refer here:
https://brainly.com/question/30233723#
#SPJ11
the unit cell in a certain lattice consists of a cube formed by an anion, a, at each corner, an anion in the center, and a cation,x, at the center of each face. how many anions and cations are there in the unit cell?
Answer: There are 8 anions and 6 cations in the unit cell.
There are 8 anions and 6 cations in the unit cell. The unit cell consists of a cube, with an anion, 'a', at each corner, an anion in the center, and a cation, 'x', at the center of each face.
The cube is made up of 8 cubes, each of which is made up of one anion at each corner, and one cation at the center. Therefore, there are 8 anions in the unit cell, one at each corner. In addition, there is an anion in the center of the unit cell.
The 6 cations are located in the center of each of the faces of the cube. The cations are located in the middle of each face and therefore, there are 6 cations in the unit cell.
In total, there are 8 anions and 6 cations in the unit cell.
Learn more anions and cations here:
https://brainly.com/question/20781422#
#SPJ11
if the concentration of zn2 is 0.10 m, what concentration of cr3 should be used so that the overall cell potential is 0 v?
Answer: The concentration of Cr3 needed to achieve a cell potential of 0 V is 0.0310 M.
To calculate the concentration of Cr3 needed for the overall cell potential to be 0 V, you will need to use the Nernst equation. The equation is as follows: Ecell = E°cell - (2.303 RT/nF) * lnQ, where Ecell is the cell potential, E°cell is the standard cell potential, R is the gas constant, T is the temperature, n is the number of moles of electrons involved in the reaction, and F is the Faraday constant.
Given the information in the question, the concentration of Zn2 is 0.10 M, you can calculate the concentration of Cr3 needed to achieve a cell potential of 0 V:
Ecell = 0 V
E°cell = E°cell (given)
R = 8.314 J/K•mol
T = 298 K (room temperature)
n = 2 (number of moles of electrons involved)
F = 96485 C/mol
Substituting these values into the equation, you get: 0 = E°cell - (2.303 * 8.314 * 298/2*96485) * lnQ.
Solving for Q (the reaction quotient), you get
Q = (E°cell/2.303RT/nF)
= (1.1V/2.303 * 8.314 * 298/2*96485)
= 0.0310 M.
Therefore, the concentration of Cr3 needed to achieve a cell potential of 0 V is 0.0310 M.
Learn more about concentration here:
https://brainly.com/question/10725862#
#SPJ11
the second electron affinity values for both oxygen and sulfur are unfavorable (endothermic). explain.
Explanation:
If we look at the definition of the second electron affinity:
The second electron affinity is the enthalpy change when one mole of gaseous 2⁻ ions is formed from one mole of gaseous 1⁻ ions
The equations of the second electron affinity for oxygen and sulfur:
O⁻ (g) + e⁻ → O²⁻ (g)
S⁻ (g) + e⁻ → S²⁻ (g)
This process is endothermic as we are trying to combine an electron with a negative ion, and so we must overcome the repulsion. Applying energy will overcome it.
The second electron affinity is the energy change that occurs when an atom in the gaseous state gains an additional electron.
For both oxygen and sulfur, the second electron affinity values are unfavorable, meaning that the energy change that occurs is endothermic. This means that energy is being absorbed by the atom, and the atom is becoming more stable.
To understand why the second electron affinity values for oxygen and sulfur are unfavorable, it is important to look at the electron configurations of these atoms. Oxygen's electron configuration is 2s22p4, meaning it has 8 electrons in its outermost shell. Sulfur has an electron configuration of 2s22p63s2, meaning it has 16 electrons in its outer shell. Since both of these atoms have a full outer shell of electrons, they are not in need of an additional electron, and therefore do not have a strong tendency to gain one. As a result, it takes a lot of energy for the atom to gain an additional electron, meaning the second electron affinity value is unfavorable (endothermic).
In conclusion, the second electron affinity values for oxygen and sulfur are unfavorable (endothermic) because they already have full outer shells of electrons and do not have a strong tendency to gain an additional electron.
To know more about endothermic reaction click on below link :
https://brainly.com/question/23184814
#SPJ11
two compounds are both composed of the exact same types and number of atoms. however, the atoms are connected in different ways in each compound. these two compounds would be classified as .
Answer:
Isomers
Explanation:
Molecules with the same molecule formula but different structural formulae
would the volume be different if the gas was argon (under the same conditions)? match the words in the left column to the appropriate blanks in the sentences on the right.
No, the volume would not be different if the gas was argon under the same conditions as two different gases that have the same number of moles, under the same conditions of temperature and pressure, would have the same volume.
"Explanation:In simple terms, the volume of a gas is proportional to the temperature, pressure, and number of particles (in moles) present. Therefore, under the same conditions of temperature, pressure, and number of particles, the volume of a gas will be the same, regardless of the identity of the gas.If the same number of moles of two different gases (such as nitrogen and argon) are present in the same container under the same temperature and pressure conditions, the volume of the two gases will be the same.In general, the volume of a gas is proportional to the number of moles of gas present in a container under constant temperature and pressure conditions. It follows that two different gases that have the same number of moles, under the same conditions of temperature and pressure, would have the same volume.
For more such question on gas
https://brainly.com/question/20492463
#SPJ11
an organism that uses inorganic co2 as its carbon source is called a(n) while an organism that must obtain its carbon in an organic form is referred to as a(n)
An organism that uses inorganic CO₂ as its carbon source is called an autotroph, while an organism that must obtain its carbon in an organic form is referred to as a heterotroph.
An autotroph is able to produce its own organic molecules from inorganic sources using energy from light, inorganic chemical reactions, or both. Photosynthesis is a type of autotrophy in which energy from sunlight is used to convert carbon dioxide into carbohydrates.
On the other hand, heterotrophs are organisms that must obtain their organic molecules by consuming other organisms or their byproducts.
They do not have the ability to make their own organic molecules from inorganic sources. Examples of heterotrophic organisms include animals, fungi, and many bacteria.
To know more about autotroph click on below link:
https://brainly.com/question/11209881#
#SPJ11
a solution at room tempearature with a ph of less than 7 will be: select the correct answer below: acidic basic neutral depends on the solution
a. Acidic
b. Basic
c. Neutral
d. Depens on the solution
The correct answer is the option a) acidic. A solution at room temperature with a pH of less than 7 will be acidic.
What are acids and bases?Acids and bases are two types of chemical compounds that are important to human life. Acids are substances that have a pH of less than 7. They taste sour and, when mixed with a base, form a neutral substance. Acids are often used in industrial processes, such as cleaning or etching metals, as well as in medicine.
Bases are substances that have a pH of greater than 7. They taste bitter and have a slippery feel. When mixed with an acid, they form a neutral substance. Bases are commonly used in cleaning products and in the production of fertilizers and plastics.
A solution at room temperature with a pH of less than 7 will be acidic.
Therefore, the correct answer is (a) Acidic.
To learn more about pH refer: https://brainly.com/question/16086492
#SPJ11
calculate the molarity of a solution made from 2.63 moles of nacl dissolved in a total volume of 500.0 ml.
The molarity of a solution made from 2.63 moles of nacl dissolved in a total volume of 500.0 ml is 5.26 M.
Molarity is the concentration of a solution in terms of moles of solute per liter of solution. The formula for calculating the molarity of a solution is as follows:
Molarity = moles of solute / volume of solution (in liters)
Given,
Moles of solute (NaCl) = 2.63 mol
Total volume of the solution = 500.0 mL = 0.5 LA
substitute the given values in the formula,
Molarity = 2.63 / 0.5
Molarity = 5.26 M
The molarity of the solution made from 2.63 moles of NaCl dissolved in a total volume of 500.0 mL is 5.26 M.
For more such questions on molarity , Visit:
https://brainly.com/question/14469428
#SPJ11
if the initial concentration of a is 0.0275 m and the rate constant has a value of 0.0082 s-1, what is the concentration of a after 540.0 s?
If the initial concentration of A is 0.0275 M and the rate constant has a value of 0.0082 s^-1, what is the concentration of A after 540.0 s? The rate of reaction can be expressed as follows: rate = -d[A]/dt = k [A]The integrated rate law for a first-order reaction is: ln [A]t/[A]0 = -kt Where [A]t is the concentration of the reactant at a particular time t.
[A]0 is the initial concentration of the reactant at t=0.k is the rate constant.t is the time of the reaction. As a result, we can rearrange the equation to find the concentration of the reactant at a specific time t as follows: ln[A]t = -kt + ln[A]0Given that the initial concentration of A is 0.0275 M,
the rate constant has a value of 0.0082 s^-1, and we want to find the concentration of A after 540.0 s.We will substitute the provided values into the equation as follows:
ln[A]t = -kt + ln[A]0ln[A]t = (-0.0082 s^-1) (540.0 s) + ln (0.0275 M)ln[A]t = -4.4358 + ln(0.0275)ln[A]t = -4.4358 - 3.5941ln[A]t = -8.0299[A]t = e^-8.0299[A]t = 0.000293 M Therefore, the concentration of A after 540.0 s is 0.000293 M.
To know more about Concentration refer here:
https://brainly.com/question/10725862#
#SPJ11
what is the volume of 1.00 mole of H2
Answer:
22.414 [tex]dm^{3}[/tex] at S.T.P and 24 [tex]dm^{3}[/tex]
Explanation:
Volume of one mole of gas at standard temperature and pressure, stp, (0 °C, 1 atm) is 22.4 dm3. At room temperature and average pressure, rtp, the volume of any gas is approximately 24 dm3.
which compound in each pair below would you expect to have a greater fluorescence quantum yield? explain
The compound O,O'-dihydoxyazobenzene, have a greater fluorescence quantum yield because of the rigidity provided by the -N=N- group. Option D is correct.
Fluorescence quantum yield is a measure of the efficiency of a molecule to emit fluorescence, which is dependent on various factors, including the rigidity or flexibility of the molecule and the presence of any functional groups that can affect the electronic structure. In the given options, O,O'-dihydoxyazobenzene has a rigid structure due to the presence of the azo group (-N=N-) that is expected to restrict the molecule's vibrational freedom, thereby reducing non-radiative energy loss and enhancing fluorescence.
On the other hand, bis(o-hydroxyphenyl) hydrazine has a flexible structure due to the -NH-NH- group, which can lead to higher non-radiative energy loss, reducing the fluorescence quantum yield. Therefore, O,O'-dihydoxyazobenzene is expected to have a greater fluorescence quantum yield than bis(o-hydroxyphenyl) hydrazine.
Hence, D. O,O'-dihydoxyazobenzene, because of the rigidity provided by the -N=N- group is the correct option.
To know more about Fluorescence here
https://brainly.com/question/14742655
#SPJ4
--The given question is incomplete, the complete question is
"Which compound in each pair below would you expect to have a greater fluorescence quantum yield? A) bis(o-hydroxyphenyl) hydrazine, because of the chemical activity of the two extra H atoms. B) bis(o-hydroxyphenyl) hydrazine, because of the flexibility provided by the -NH -NH - group C) O,O'-dihydoxyazobenzene, because of the chemical activity of the -N=N- group. D) O,O'-dihydoxyazobenzene, because of the rigidity provided by the -N=N- group."--
select the weakest reducing agent from the list of answer options. all species without a phase listed are aqueous. g ni(s) pb2 sn(s) al(s) cr2 zn(s)
The weakest reducing agent from the given list of answer options is Pb2+.
A reducing agent is a substance that donates electrons, thus causing the reduction of another species. In other words, reducing agents are oxidized when they reduce another substance.
The stronger the reducing agent, the more readily it donates electrons, and the more likely it is to cause the reduction of another species. The weaker the reducing agent, the less readily it donates electrons, and the less likely it is to cause the reduction of another species.
To determine the weakest reducing agent:
Pb2+: This species can act as a reducing agent, but it is not very strong. It has a standard reduction potential of -0.13 V.
This means that it is only a weak reducing agent.
Zn(s): This is a strong reducing agent, with a standard reduction potential of -0.76 V. It can readily donate electrons, and is more likely to cause the reduction of another species than Pb2+.Cr2+: This is also a strong reducing agent, with a standard reduction potential of -0.91 V. It can readily donate electrons, and is more likely to cause the reduction of another species than Pb2+.Al(s): This is an even stronger reducing agent, with a standard reduction potential of -1.66 V. It can readily donate electrons, and is much more likely to cause the reduction of another species than Pb2+.Sn(s): This is another strong reducing agent, with a standard reduction potential of -0.14 V. It can readily donate electrons, and is more likely to cause the reduction of another species than Pb2+.Ni(s): This is the strongest reducing agent on the list, with a standard reduction potential of -0.25 V. It can readily donate electrons, and is the most likely to cause the reduction of another species.However, it is not one of the answer options, so we can ignore it.
From this analysis, we can conclude that Pb2+ is the weakest reducing agent from the given list of answer options.
To know more about the reducing agent https://brainly.com/question/2890416
#SPJ11
why do you think this reaction only undergoes mono iodination? think about the discussion earlier about activation and deactivation of the benzene ring and the role iodine may play once it is on the ring.
The reaction only undergoes mono iodination due to the increased reactivity of the benzene ring when iodine is added.
The electron deficient nature of the benzene ring makes it easier for the reaction to occur in a single step, rather than multiple steps.
The reaction only undergoes mono iodination due to the reactivity of the benzene ring. When iodine is added to the benzene ring, it makes the ring more electron deficient.
This increases the reactivity of the benzene ring and makes it easier for the reaction to occur in a single step.
In contrast, if more iodine is added to the ring, it makes the ring less electron deficient and thus decreases its reactivity.
This makes it harder for the reaction to occur in a single step and thus causes multiple steps to occur.
The discussion earlier about activation and deactivation of the benzene ring was related to this reaction. The deactivating group like the iodine makes the ring less reactive, thus favoring single step reactions.
Meanwhile, the activating group makes the ring more reactive, favoring multiple step reactions.
to know more about mono iodination refer here
https://brainly.com/question/16867213#
#SPJ11
trontium-90 has a half-life of 28.8 years. if you start with a 10 gram sample of strontium-90, how much will be left after 115.2 years?
After 115.2 years starting with a 10 gram sample of strontium-90, only 0.625 grams of strontium-90 will remain due to radioactive decay.
Strontium-90 is a radioactive isotope that goes through dramatic rot with a half-existence of 28.8 years. This really intends that after each 28.8-year time frame, how much strontium-90 excess in an example is divided. To decide how much strontium-90 will be left after 115.2 years, we can utilize the accompanying recipe:
N = N0 * (1/2)^(t/T1/2)
where N is the last measure of strontium-90, N0 is the underlying sum, t is the time slipped by, and T1/2 is the half-life. Subbing the given qualities, we get:
N = 10 g * (1/2)^(115.2/28.8)
N = 10 g * (1/2)^4
N = 10 g * 0.0625
N = 0.625 g
In this manner, after 115.2 years, beginning with a 10 gram test of strontium-90, just 0.625 grams of strontium-90 will stay because of radioactive rot. This estimation shows that how much radioactive material declines over the long run, which is a significant thought in the protected dealing with and removal of radioactive materials.
To learn more about trontium-90 and strontium-90, refer:
https://brainly.com/question/14102797
if a reaction is 1st order, how many half-lives are required for 99.9% of the original sample to be consumed?
In a first-order reaction, time required for completion of 99.9% is 10 times of half-life (t1/2) of the reaction.
In a first-order reaction, the rate of the reaction is inversely correlated with the concentration of the reactant. In other words, if the concentration doubles, so does the pace of the reaction. The half-life of a reaction is defined as the amount of time it takes for half of the reactant to be consumed. The half-life of a first-order reaction is given by:
t1/2 = 0.693/k
where k is the rate constant of the reaction.
The chemical kinetics rate law, which connects the molar concentration of reactants to reaction rate, uses the rate constant as a proportionality factor. The letter k in an equation designates it, which is also referred to as the reaction rate constant or reaction rate coefficient.
To know more about the half-life, refer:
https://brainly.com/question/14936355
#SPJ4
What pressure is required to reduce 50 mL of a gas at standard conditions to 20 mL at a temperature of 23◦C?
Answer in units of atm.
The pressure required to reduce 50 mL of a gas at standard conditions to 20 mL at a temperature of 23 °C is 10.656 atm. To solve this problem, the ideal gas law is used.
What is the ideal gas law?The ideal gas law is a fundamental equation of state that relates the pressure, volume, temperature, and number of moles of an ideal gas. The ideal gas law is expressed mathematically as:
PV = nRT
At standard conditions (STP), the volume of 50 mL of a gas is equivalent to 0.050 L, and the temperature is 273 K. We can use this information to find the initial number of moles of the gas:
n₁ = P*V₁/R*T₁= P(0.050 L)/(0.08206 L·atm/mol·K)(273 K) = P/2.4844
where V₁ = 0.050 L, R = 0.08206 L·atm/mol·K, and T₁ = 273 K.
To reduce the volume to 20 mL (0.020 L) at a temperature of 23°C (296 K), we can rearrange the ideal gas law equation and solve for the required pressure:
P2 = n₁*RT₂/V₂ = (P/2.4844)(0.08206 L·atm/mol·K)(296 K)/(0.020 L) = 10.656P
where T₂ = 296 K and V₂ = 0.020 L.
Therefore, the pressure required to reduce 50 mL of a gas at standard conditions to 20 mL at a temperature of 23°C is:
P₂ = 1 atm × 10.656 = 10.656 atm
Thus, the pressure required to reduce the volume of the gas is 10.656 atm.
To know more about the ideal gas law, visit:
https://brainly.com/question/28257995
#SPJ1
adding this test solution will precipitate sulfate ions: select one: a. naoh b. bacl2 c. hno3 d. nh4cl
Answer: The solution that will precipitate sulfate ions is B. BaCl2.
How do you test for sulfate ions?
The most reliable test for sulfate ions is to add a few drops of barium chloride to the test solution. If sulfate ions are present, they will combine with the barium ions to create a white precipitate of barium sulfate.
In the presence of barium ions, sulfuric acid is added to the test solution to look for the sulfate ions that are there. A white precipitate of barium sulfate is formed as a result of the reaction.
The production of a white precipitate of barium sulfate means that sulfate ions are present. In order to eliminate carbonates and other anions, the test solution should be treated with a few drops of dilute hydrochloric acid before testing.
Learn more about Barium chloride here:
https://brainly.com/question/14444265#
#SPJ11
what is the mass of sodium chloride required to create a 0.875 m solution 534 g of water. how many moles of nacl is required
The mass of sodium chloride that is required to create a 0.875 M solution 534 g of water is 27.291 g and 0.467 moles of NaCl is required.
Mass of water = 534 g
Molality of the solution = 0.875 m
Molality is the number of moles of solute per kilogram of solvent.
It is represented by the formula:
Molality = number of moles of solute / kilogram solvent
Its mathematical expression is:
m = n/kg
Now we will convert the g into kg.
Mass of water = 534 g× 1kg/1000 g = 0.534 kg
putting the values in formula:
0.875 m = n / 0.534 kg
n = 0.467 mol
Now we will calculate the mass of sodium chloride:
Mass = number of moles × molar mass
Mass = 0.467 mol × 58.44 g/mol
Mass = 27.291 g
Thus, the required mass and moles of NaCl are 27.291g and 0.467mol respectively.
To know more about molality here
https://brainly.com/question/27987133
#SPJ4
How many moles are in 8.52 x 10^33 molecules of Carbonic Acid (23)?
Answer: There are approximately 141.7 moles
Explanation:
To convert the number of molecules of a substance to the number of moles, we need to divide the number of molecules by Avogadro's Number, which is approximately 6.022 x 10^23 molecules per mole.
Therefore, to calculate the number of moles in 8.52 x 10^33 molecules of carbonic acid (H2CO3), we can use the following formula:
Number of moles = Number of molecules / Avogadro's Number
Number of moles = 8.52 x 10^33 / 6.022 x 10^23
Number of moles = 141.7 mol
Therefore, there are approximately 141.7 moles of carbonic acid in 8.52 x 10^33 molecules of carbonic acid.
Read more about Moles and Molecules:
https://brainly.com/question/24191825
which of the following molecules will not contain a multiple bond in its lewis structure? multiple choice c2h2 cs2 ncl3 co2 ch2o
The Lewis structure of the compound is used to predict its chemical behavior. In the given options, which of the following molecules will not contain a multiple bond in its Lewis structure is Carbon dioxide (CO2) will not contain a multiple bond in its Lewis structure.
Carbon dioxide (CO2) is made up of two oxygen atoms that are covalently bonded to a single carbon atom. CO2 has a linear geometry, with each O=C=O bond angle measuring 180 degrees. In its Lewis structure, CO2 contains two double bonds. The carbon atom has a total of four valence electrons, while each oxygen atom has a total of six valence electrons.
Both the O atoms and C atom share four valence electrons in this covalent compound. One of the oxygen atoms binds with carbon by a double bond, and the other oxygen atom binds with the carbon atom through a double bond. All the octets are completed in the molecule.
Each molecule is different and has different Lewis structures. The elements in the same group of the periodic table have the same valency, so they follow the same Lewis structure pattern. For example, all the halogens have a valency of 1 and follow the same pattern in the Lewis structure.
For more question on Lewis structure click on
https://brainly.com/question/20300458
#SPJ11
g if a chemical spill occurs in lab, the best step to take is...group of answer choicesimmediately use the safety showerimmediately let the instructor knowcover the spill with absorbent material such as paper towelsquickly rinse the area with as much cool water as possible
If a chemical spill occurs in the lab, the best step to take is to quickly rinse the area with as much cool water as possible. A chemical spill can lead to harmful chemical exposure, and the best way to avoid exposure is to act fast and neutralize the spill.
What is the best way to handle a chemical spill?Chemical spills can occur anywhere that hazardous chemicals are being used, but they are most common in industrial and laboratory settings. If you come across a chemical spill, it's important to act quickly and safely to prevent exposure. Here are the steps to follow in the event of a chemical spill:
Step 1: Assess the situation
The first step in handling a chemical spill is to assess the situation. Determine the type and quantity of the spilled material, as well as the potential hazards associated with it. This will help you determine the appropriate response.
Step 2: Evacuate the area
If the spill is large or the chemical is particularly dangerous, evacuate the area immediately. Alert others in the area to evacuate as well.
Step 3: Alert others
Once you have assessed the situation and determined the appropriate response, alert others in the area to the spill. Notify your instructor or supervisor and follow their instructions.
Step 4: Personal Protective Equipment (PPE)
When responding to a chemical spill, be sure to wear appropriate personal protective equipment (PPE), such as gloves, goggles, and lab coats.
Step 5: Use absorbent material
Use absorbent material, such as paper towels or absorbent socks, to contain the spill and prevent it from spreading. Once the spill is contained, dispose of the absorbent material according to your lab's waste disposal guidelines.
Step 6: Rinse the area with water
Quickly rinse the area with as much cool water as possible. This will help to neutralize the spill and prevent further damage.
Step 7: Use safety shower
If the spilled chemical comes in contact with your skin, use a safety shower to rinse off the chemical. Make sure to rinse thoroughly for at least 20 minutes.
Step 8: Dispose of contaminated materials
Dispose of contaminated materials according to your lab's waste disposal guidelines. Make sure to properly label all waste containers.
So, in a chemical spill the right thing to do will be 4. quickly rinse the area with as much cool water as possible
Learn more about chemical spill on:
https://brainly.com/question/30125064
#SPJ11
if an isotope has a half-life of 4 billion years, then in 4 billion years what will happen? group of answer choices the original amount will have doubled. all of the original amount will still be present. all of the original amount will have decayed. half of the original amount will still be present.
If an isotope has a half-life of 4 billion years, then in 4 billion years, half of the original amount will still be present.
What is an isotope?An isotope is a variant of a chemical element that has the same number of protons but a different number of neutrons in the nucleus of an atom.
For example, carbon has two common isotopes: carbon-12 and carbon-14. Carbon-12 has six protons and six neutrons in its nucleus, whereas carbon-14 has six protons and eight neutrons.
Since the number of protons in an atom determines its chemical properties, isotopes of the same element have nearly identical chemical characteristics. Because isotopes have different numbers of neutrons, they have different atomic masses, but their physical and chemical properties are almost identical.
The half-life of a radioactive isotope is the amount of time it takes for half of the original quantity of the isotope to decay. Half-life is a critical consideration in nuclear medicine and radiology since it determines how long a radioactive substance will be active in the body before being completely eliminated.
The half-life of a given radioactive isotope is constant and cannot be altered by any external factors, such as temperature or pressure, which is a unique characteristic of radioactive decay.Isotopes can be found naturally or can be artificially made, and they can be radioactive or stable
To know more about half-life click on below link:
https://brainly.com/question/24710827#
#SPJ11