Answer:
Photosynthesis is the process by which plants use sunlight, water, and carbon dioxide to create oxygen and energy in the form of sugar
You wish to prepare a buffer containing CH3COOH with a pH of 5.14. If the pka of acetic acid is 4.74, what ratio of
[CH3COO-]/[CH3COOH] must you use?
A 0.70
B 4.0
C 0.40
D 2.0
E 2.5
Answer:
E
Explanation:
Recall the Henderson-Hasselbalch equation:
[tex]\displaystyle \text{pH} = \text{p}K_a + \log \frac{[\text{Base}]}{[\text{Acid}]}[/tex]
For a pH of 5.14 with the given pKa of 4.74, solve for the ratio between acetate and acetic acid:
[tex]\displaystyle \begin{aligned} (5.14) & = (4.74) + \log\frac{[\text{CH$_3$COO$^-$}]}{[\text{CH$_3$COOH}]} \\ \\ \log\frac{[\text{CH$_3$COO$^-$}]}{[\text{CH$_3$COOH}]}& = 0.40 \\ \\ \frac{[\text{CH$_3$COO$^-$}]}{[\text{CH$_3$COOH}]} & = 10^{0.40} \\ \\ & = 2.5\end{aligned}[/tex]
In conclusion, the answer is E.
How did Darwin study artificial selection in the late 1800's?
A. He studied the animals on the Galapagos Island.
B. He studied selectively bred animals.
C. He studied the animals in a Zoo.
D. He studied animals in the wild.
Many cigarette lighters contain liquid butane, C4H10, which has a ∆H°ƒ = –147.6 kJ/mol. Using enthalpies of formation, calculate the quantity of heat produced when 1.0 g of butane is completely combusted in air. (Write the equation for the process first)
For cigarette lighters containing liquid butane, C4H10, the quantity of heat produced is mathematically given as
q= -49.2 KJ
What is the quantity of heat produced when 1.0 g of butane is completely combusted in air?Generally, the equation for the Chemical reaction is mathematically given as
C₄H₁₀(l) + 6.5 O₂(g)---->4 CO₂(g) + 5 H₂O(l)
Therefore
dH°r = .(-393.5 ) + 5.(-285.5] - [1.(-147.6 )+6.5.
dH°r = -2853.9 kJ/mol
In conclusion, No.of mole
Nm = 1g/58g/mol
Nm= 0.01724mol
Hence, Heat of combustion
q = dH°r x moles
q = -2853.9 ×0.01724
q= -49.2 KJ
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How many electrons are in the n = 2 shell of a magnesium atom?
Answer:
eight
Explanation:
That means there are 12 electrons in a magnesium atom
hope this helps
Which statement is true about the Group 1 metals?
a
They are the most reactive metals in the periodic table.
b
They all have one shell or ring.
c
These metals do not conduct electricity well.
d
The metals of the group are called halogens.
Answer:
The metals of the group are called halogens.
Explanation:
hope it works if not im very sorry for wasting ur time :)
Write a net ionic equation for the reaction that occurs when excess hydroiodic acid and nickel(II) sulfide are combined.
Explanation:
Step 1: Write the balanced "molecular" equation:
[tex]2HI(aq) + NIS (s) → NiI₂(aq) + H₂S(g)[/tex]
Step 2: H₂S is written in molecular form. Consult the solubility and net ionic equation rules on the information page to determine which of the other substances will dissociate:
[tex]2HI(aq) + NIS (s) → NiI₂(aq) + H₂S(g)[/tex]
yes no yes
Step 3: Dissociate all soluble salts, strong acids, and strong bases (except calcium hydroxide). Leave together all "not soluble" salts and weak acids or bases:
[tex] {2H₃O}^{ + } (aq) + {2I}^{ - } (aq) + NiS(s)→ { Ni}^{2 + }(aq) + {2I}^{ - }(aq) + H₂S(g) + 2H₂O(l)[/tex]
Step 4: Cross out "spectator ions" that appear on both sides of the reaction (these ions do not participate in the chemistry) and rewrite the "net" reaction using the smallest possible coefficients:
[tex] {2H₃O}^{ + } (aq) + NiS(s) → { Ni}^{2 + } (aq) + H₂S(g) + 2H₂O(l)[/tex]
If 53.6 g of Cu(NO3)2 were produced, how many grams of Cu reacted?
Answer:
The amount of grams of Cu that reacted is 18.15g
Explanation:
Where:.
Cu= 63.5
O= 16
N= 14
Molar mass of Cu(NO3)2 =
63.5 + 2(14+ 48)
63.5 + 124
=187.5
THEN IF 63.5g of Cu reacted in 187.5g of Cu(NO3) 2
x of Cu is in - - - - >53.6g
x= 63.5 * 53.6/187.5
x= 3403.6/187.5
x= 18.15g of Cu reacted.
1. Which trait is most likely to be passed on to its organism’s offspring?
Answer:Evolution
Evolution is the process by which populations of organisms change over generations. … If a trait is advantageous and helps the individual survive and reproduce, the genetic variation is more likely to be passed to the next generation (a process known as natural selection).
- 2HCI(aq) › ZnCl2(aq) + Ha(g) / was given four different hydrochloric acid solutions, each of had a different molarity. He was curious to see what would en if he put a 5 gram piece of zinc metal into 50 ml of each olution. In which HCI solution would the zinc metal have the est rate of reaction? [ think about how you will compare 5.1 5M HCI LOM HCI 1.5M HCIZn(s) + 2HC|(aq) > ZnCl(aq) + H2(g) Bobby was given four different hydrochloric acid solutions, each of which had a different molarity. He was curious to see what would happen if he put a 5 gram piece of zinc metal into 50 ml of each HI solution. In which HI solution would the zinc metal have the quickest rate of reaction? [ think about how you will compare dollars. ] A) .5M HCI B) 1.0M HCI C) 1.5M HCI D) 2.OM HCI
The rate of reaction between zinc and either HCl or HI will be highest in the 2.0 M solutions since they had the highest concentrations.
How does concentration affect the rate of a reaction?The rate of a reaction increases with increase in concentration of the reactants and decreases with decrease in concentration of the reactants.
The solutions of the HCl and HI that has the highest are those with concentrations of 2.0 M.
Therefore, the rate of reaction between zinc and either HCl or HI will be highest in the 2.9l0 M solutions.
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how many oxygen atom in 0.25 mol ca(No3)2?
Answer:
1 molecule of Ca(NO3)2 has 6 oxygen atoms.
experimental evidence indicates that the nucleus of an atom
The nucleus of an atom is positively charged and contains most of the mass if the atom.
What is an atom?An atom is the smallest particle of a an element that can take part in a chemical reaction.
Atoms are made up of other smaller sub-particles which are:
neutrons which are neutral protons which are positively charged electrons which are negatively chargedThe protons and neutrons are found in the nucleus of an atom
The electrons are found regions around the nucleus.
Due to the positive charge of the protons, the nucleus of an atom are positively charged and is massive.
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Identify each compound as an electrolyte or a nonelectrolyte.
MgCl, (magnesium chloride)
CH, On (sucrose table sugar)
H, SO. (sulfuric acid)
DONE
The following solutions are electrolytes/non electrolytes;
magnessium chloride- electrolytesucrose - non electrolytesulfuric acid - electrolyteWhat is an electrolyte?An electrolyte is a substance that conducts electricity in solution. An electroyte must be able to dissociate into ions. It is these ions that are the charge carriers in solution.
Now let us define which of these are electrolytes;
magnessium chloride- electrolytesucrose - non electrolytesulfuric acid - electrolyteLearn mlore about electrolyte : https://brainly.com/question/27132799
Answer:
A B A
Explanation:
A sample of water goes through a temperature change of -74.14 °C while releasing 578.7 joules of heat. The specific heat capacity of water is 4.184 J/(g·°C). What is the mass of this sample? grams (Report your answer using 4 significant figures).
Answer:
[tex] \boxed{ \sf \: m = 1.866 \: grams}[/tex]
Explanation:
Given:
Change in temperature ∆T= -74.14°C
Heat(Energy) released Q= 578.7 joules
Specific heat capacity s = 4.184 J/(g·°C)
To find:
Mass of the sample (m)=?
Solution:
[tex] \sf s= \frac{Q}{m \cdot \Delta T} \\ \sf \: Substituting \: the \: given \: parameters \\ \sf 4.184 = \frac{578.7}{m \times ( - 74.14)} \\ \sf m = \frac{578.7}{4.184 \times ( - 74.14)} \\ \sf m = \frac{578.7}{310.20176} \\ { \sf m = 1.8655 \approx1.866 \: grams}[/tex]
Since, we need the answer in 4 significant figures,
[tex] \boxed{ \sf \: m = 1.866 \: grams}[/tex]
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14. Which statement gives you enough information to say that the atom is electrically neutral?
A. The atom has 15 neutrons and 15 electrons.
B. The atom has 19 electrons and 19 neutrons.
C. The atom has 4 neutrons and 4 protons.
D. The atom has 7 protons and 7 electrons
The statement which gives you enough information to say that the atom is electrically neutral is: The atom has 7 protons and 7 electrons.
What is mass? In the shortest way possible
Answer:
Mass is the quantity of matter in a physical body.
Explanation:
mass bro
Answer:
a coherent, typically large body of matter with no definite shape.
Explanation:
a mass of curly hair
The thick old crust of earth is crust
What mass of water will be needed to change its temperature 25°C using 4,532 J of heat
energy?
The mass of the water that will be needed to change its temperature by 25°C is : 43.33 grams
Given data :
Energy = 4532 J
Change in temperature = 25°C
Cw = 4.184 J/gk
Determine the mass of water needed
We will apply the formula below
Q = mCwΔt ---- (1 )
4532 = m * 4.184 * 25
therefore :
m = 4532 / 104.6
= 43.33 grams
Hence we can conclude that the mass of water needed to change the temperature by 25°C is 43.33 grams
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How many grams of solute are needed to make 2.50 L of a 1.75 M solution of Ba(NO3)2?
1143.4grams of solute are needed to make 2.50L of a 1.75M solution of Ba(NO3)2. Details about molarity can be found below.
How to calculate mass?The mass of a substance can be calculated by multiplying the number of moles by its molar mass.
However, the number of moles can be calculated by using the following formula:
Molarity = no of moles ÷ volume
no of moles = 1.75 × 2.5
no of moles = 4.38mol
molar mass of Ba(NO3)2 = 261.34g/mol
mass of Ba(NO3)2 = 261.34 × 4.38
mass of Ba(NO3)2 = 1143.4grams.
Therefore, 1143.4grams of solute are needed to make 2.50L of a 1.75M solution of Ba(NO3)2.
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12. If you had 375 K, what would the temp be in Celsius?
a. 648°C
c. 500°C
b. 435°C
d. 102°C
Answer:
As Per Provided Information
Given temperature is 375K
We have been asked to find the temperature in Celcius .
[tex] \boxed{\bf \: {}^{ \circ}C =Given \: Temperature \: in \: k \: - 273}[/tex]
Substituting the given value in above equation and let's solve it
[tex] \qquad \longrightarrow\sf \: {}^{ \circ}C = \: 375 - 273 \\ \\ \\ \qquad \longrightarrow\sf \: {}^{ \circ}C = \: 102[/tex]
Therefore,
Temperature in Celcius will be 102 °CSo, your answer is d) 102°C
Please help me on all of them!!
(1) The number of moles of nitrogen trihydride produced is 3.63 moles.
(2) The molar ratio not represented is 2 moles of N₂ = 3 moles of NH₃.
Chemical reaction of Nitrogen and hydrogen
The balanced chemical reaction of Nitrogen and hydrogen is given in the equation below;
N₂ + 3H₂ → 2NH₃
From equation above;
3 moles of H₂ --------------------> 2 moles of NH₃
5.45 moles of H₂ ----------------> ? moles of NH₃
= (5.45 x 2) / 3
= 3.63 moles of NH₃
Molar ratio not represented in the above balanced equationFrom the equation above, we have the following molar ratios
2 moles of NH₃ = 3 moles H₂1 mole of N₂ = 2 moles of NH₃ 3 moles H₂ = 1 mole of N₂Thus, the only molar ratio not represented in the balanced chemical equation of Nitrogen and hydrogen gas is 2 moles of N₂ = 3 moles of NH₃.
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À chemist reacted 17.25 grams of sodium metal with an excess amount of chlorine gas. The chemical reaction that occurred is showr
Na + ch2- Nacl
If the percentage yield of the reaction is 88%, what is the actual yield? Show your work, including the use of stoichiometric calculations and conversion factors.
Answer:
Actual yield is 38.57
Explanation:
Percentage yield = Actual yield / theoretical yield X 100
Percent yield x theoretical yield / 100 = actual yield
Write the balanced chemical equation:
2Na + CI2 = 2NaCI
Given is 17.25 g Sodium metal (limiting reactant) with excess being chlorine gas
Percent yield is 88%
Mole of Na = 17.25 g / 22.98 = 0.750
Calculate the Theoretical Yield to solve for Actual Yield
Theoretical yield = 0.75 x molar mass of NaCI
Theoretical yield = 0.75 x 58.44 = 43.83 g
When plugged into the original percentage yield formula:
Actual yield = 88 x 43.83 / 100 = 38.57 g
What is the IUPAC name for the compound shown?
Answer:
2,2,3-trimethylpentane
Explanation:
The iupac name for the compound shown is 2,2,3-trimethylpentane
Are two atoms of the same element identical?
Answer: No, two atoms belonging to the same chemical element are not necessarily identical.
Explanation:
I hope that was helpful
PLEASE HELP 50 Points which of Erwin Shrodinger's contributions are present in the modern atomic model and which were eventually disproven and thus are not part of the modern model?
Answer:yes is yes = 0iq
Explanation: hes was a prodogy he helped alot of people -500iq
What does thermodynamics study?
A. The properties of the nucleus
B. The strength of chemical bonds
C. The energy of motion and heat
D. The behavior of charged particles
Thermodynamics is the science that deals with work, temperature and heat. It studies the energy of motion and heat. Thus, option C is accurate.
What is thermodynamics?Thermodynamics, thermo means heat and energy and dynamics means motion or movement. It is a branch of science that relates the entropy, enthalpy, and motion of matter.
It is used in physics and chemistry to depict the change in the system influenced by the surrounding. The release or the gain of heat in a thermodynamic system is studied as well.
Therefore, in option C the energy of motion and heat are studied in thermodynamics.
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The table below lists three characteristics of an atom of an element
Number of protons:10
Number of neutrons:10
Number of Valence Electrons:8
An atom of which element is described by the data in the table?
Ten grams of water will require --- calories to raise the temperature 1° C.
Explanation:
Specific heat capacity of water is 1cal/g/∘C. 1 cal heat is required to increase the temperature of 1 g of water by 1∘C. To increase the temperature of 10 g water by 1∘C, 10 calories of heat is required
PLEASE MARK ME BRAINLIEST IF MY ANSWER IS CORRECT PLEASEHow is the temperature affected (increased or decreased) when the iron block is placed in the water?
a. the iron black (temp increase or decrease)
b. the water (temp increase or decrease)
Question 1 options:
Blank # 1
Blank # 2
How many grams of CO2 ( Carbon dioxide gas ) will exert a pressure of 769 mmHg at a volume of 52.3L at 425K?
66.9 grams of CO₂ ( Carbon dioxide gas ) will be required to exert the given value of pressure at the given volume and temperature.
Ideal Gas LawThe Ideal gas law or general gas equation emphasizes on the state or behavior of a hypothetical ideal gas. It states that "the pressure multiplied by volume is equal to moles multiply by the universal gas constant multiply by temperature.
It is expressed as;
PV = nRT
Where P is pressure, V is volume, n is the amount of substance, T is temperature and R is the ideal gas constant ( 0.08206 Latm/molK )
Given the data in the question;
Pressure P = 769 mmHg = 1.01184atmVolume V = 52.3LTemperature T = 425KAmount of gas n = ?To determine the amount of gas, we substitute our values into the expression above.
PV = nRT
n = PV / RT
n = ( 1.01184atm × 52.3L ) / ( 0.08206Latm/molK × 425K )
n = 52.919232Latm / 34.8755Latm/mol
n = 1.52mol
Now, we the mass of CO₂ ( Carbon dioxide gas ).
Molar mass of CO₂ is 44.01 g/mol
Hence;
1.52mol × 44.01 g/mol = 66.9g
Therefore, 66.9 grams of CO₂ ( Carbon dioxide gas ) will be required to exert the given value of pressure at the given volume and temperature.
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In chemistry, “partial pressure” refers to the pressure that each gas in a gas mixture exerts against its surroundings, such as a sample flask, a diver’s air tank, or the boundary of an atmosphere. You can calculate the pressure of each gas in a mixture if you know how much of it there is, what volume it takes up, and its temperature. You can then add these partial pressures together to find the total pressure of the gas mixture, or, you can find the total pressure first and then find the partial pressures.