Answer:
Option B. 384 nm
Explanation:
From the question given above, the following data were obtained:
Frequency (f) = 7.81×10¹⁴ Hz
Velocity of photon (v) = 3×10⁸ m/s
Wavelength (λ) =?
The wavelength of the photon can be obtained as follow:
v = λf
3×10⁸ = λ × 7.81×10¹⁴
Divide both side by 7.81×10¹⁴
λ = 3×10⁸ / 7.81×10¹⁴
λ = 3.84×10¯⁷ m
Finally, we shall convert 3.84×10¯⁷ M to nm. This can be obtained as follow:
1×10¯⁹ m = 1 nm
Therefore,
3.84×10¯⁷ m = 3.84×10¯⁷ m × 1 nm / 1×10¯⁹ m
3.84×10¯⁷ m = 384 nm
Thus, the wavelength of the photon is 384 nm
CHEMISTRY FORM THREE Exercise 2.1 1) Not all metals share the typical metal properties.name a metal that is: a. hard and strong b. malleable at room temperature
a) The strongest metal on the planet is tungsten.
When it comes to tensile strength, tungsten tops all other metals. One of the strongest metals known to man, tungsten has an ultimate strength of 1510 Megapascals.
In addition to having the greatest melting point of any unalloyed metal, tungsten boasts greater strength. Tungsten is frequently employed in electrical and military applications due to its strength.
Tin is a malleable, silvery-white metal that is highly flammable at ambient temperature.
Metal malleability is a complex subject. There is no objective test available to measure this feature, as we previously stated. We most frequently test it for hardness.
The most malleable and ductile metals are gold and silver. Pure gold and silver are too soft to be used to create items that will keep their shape.
Metals may be molded into different shapes, such as thin sheets or foils, without breaking or shattering because they are malleable. They are also ductile, making it simple to draw them into wires.
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Separation of mixtures and purification of chemical substances
Answer:
I don't understand what to do with this
Which substance reacts with an acid or a base to control pH?
buffer
salt
titration
sodium ion
Answer:
Your answer would be a buffer, they control pH levels.
Explanation:
Buffer is a substance that reacts with an acid or a base to control pH. Hence, option A is correct.
What is pH?pH is a measure of how acidic/basic water is.
Buffers are solutions that resist a change in pH after adding an acid or a base. Buffers contain a weak acid (HA) and its conjugate weak base (A−).
Hence, option A is correct.
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word equation for k2co3->k2o+co2
Answer:
potassium carbonate -> potassium oxide + carbon dioxide
Explanation:
remember to look at your periodic table, located each element so in this case you would locate k,c and o which are potassium, carbon and oxygen. From there you use nomenclature rules to get your answer.
What does the red line running through Earth represent?
Answer: The Equator because it divides the Earth into the Northern and Southern hemispheres.
Explanation:
GivenL C2H2 + 5O2 ------> 4 CO2 + 2H2O
If 9.5 L of CO2 are produced, how many liters of O2 will be needed for this reaction? Show work
Answer:
101 L
Explanation:
35.0 g KOH ÷ 56.09 g/mol KOH × (1 mol H2O/ 1 mol KOH) × 18 g/mol H2O = 11.2 g H2O
35.0 g HCl ÷ 36.45 g/mol HCl × (1 mol H2O/ 1 mol HCl) × 18 g/mol H2O = 17.3 g H2O
35.0 g KOH is the limiting reactant
Calculate the pH if the [OH-] concentration is 5.9x10-1 M.
Which statement is correct about the rate of a chemical reaction? (5 points)
a. It increases when the concentration of reactants increases.
b. It does not depend on the concentration of reactants.
c. It increases when the temperature decreases.
: d. It does not depend on the temperature.
Answer:
they don't depend on the temperature
When a person weighs himself in pounds, which system of measurement is he using?
Answers: customary or metric
Answer:
it is the British imperial and united states customary systems
PLS HELP DUE NOW
What is the pH of each solution?
[H3O+] = 4.78 x 10-2 M
and
pOH = 4.56
Answer:
First solution pH = 1.32
Second solution pH = 9.44
Explanation:
For the first solution:
[H₃O⁺] = 4.78 x 10⁻² MWhich is the same as saying 4.78 x 10⁻² M is [H⁺].
Knowing [H⁺], we can now calculate the pH:
pH = -log[H⁺]pH = 1.32As for the second solution, we can calculate the pH by keeping in mind the relationship between pOH and pH:
pOH + pH = 144.56 + pH = 14pH = 9.44Are all antigens foreign substances?
No, not all antigens are foreign substances.
An antigen is any substance that can trigger an immune response, including the production of antibodies. Some antigens are naturally present in the body and are called "self" antigens which are usually not harmful, but in some cases, the immune system can mistakenly recognize them as foreign and attack them which can lead to autoimmune diseases.
Antigens bind together with antibodies and promote the elimination of harmful pathogens present in the body. They alert other parts of the immune system to take over which helps to neutralize the threat from pathogens.
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How many moles of C6H12O6 are needed to produce 38.44 grams of CO2? Round your answer to three digits after the decimal point.
C6H12O6 + 6 O2 à 6 CO2 + 6 H2O
Explanation:
38.44 g CO2 = 0.873 mol CO2
0.873 mol CO2 × (1 mol C6H12O6 / 6 mol CO2)
= 0.146 mol C6H12O6 x (180.56 g C6H12O6/ 1 mol C6H12O6)
= 26.303 gm
How are fossils useful to scientists?
Answer:
Yes they are
Explanation:
Answer:
Fossils are traces of ancient life. Scientists use fossils to gather information about the lives and evolutionary relationships of organisms, for understanding geological change.
if 3.38g of CuNO3 IS DISSOLVED IN WATER TO MAKE 0.220 M solution what is the volume of the solution in milliliters"
Answer:
To determine the volume of the solution in milliliters, we need to know the mass of CuNO3 and the concentration of the solution.
Given that 3.38g of CuNO3 is dissolved in water to make a 0.220 M solution, we can use the following formula to calculate the volume of the solution:
Volume = (Mass of CuNO3) / (Concentration of solution)
Plugging in the given values, we have:
Volume = (3.38 g) / (0.220 M)
Converting the mass to grams and the concentration to moles/liter, we have:
Volume = (3.38 g) / (0.220 mol/L)
Calculating, we find that the volume of the solution is approximately 15.36 liters.
To convert the volume to milliliters, we can multiply the volume in liters by 1000. In this case, the volume in milliliters is 15,360 ml.
Therefore, the volume of the solution in milliliters is approximately 15,360 ml.
Explanation:
distringuish between zeotropic and azeotropic mixtures
Answer:
The terms azeotropic and zeotropic are opposite to each other. The key difference between azeotropic and zeotropic mixture is that the dew point and bubble point of an azeotropic mixture intersect, whereas the dew point and bubble point of a zeotropic mixture are distinguishable.
Explanation:
What mass of O2 molecules contains the same number of oxygen atoms as 14.0 g of water?
Answer:
So 0.39 moles of oxygen are produced in 14 g of water. So that's it.
Explanation:
Which of the following statements describes all
exothermic reactions?
A. Exothermic reactions form gases.
B. Exothermic reactions require a catalyst.
C. The energy of the reactants is lower than the
energy of the products,
D. The energy of the reactants is higher than the
energy of the products.
Answer:
D
Explanation:
The energy of the reactants is higher than the energy of the products.
What is the volume of 3.00 M sulfuric aid that contain 9.809 g of H2SO4 (98.09g/mol)
Given :
Molarity of sulfuric acid solution is 3.0 M.
Amount of sulfuric acid present in solution is 9.809 g.
To Find :
The volume of solution.
Solution :
We know, molarity is given by :
[tex]Molarity = \dfrac{number \ of \ moles \times 1000}{Volume\ ( ml )}\\\\M = \dfrac{w \times 1000}{M.M \times V}\\\\3 = \dfrac{9.809\times 1000}{98.09 \times V}\\\\V = \dfrac{1000}{10\times 3}\ ml\\\\V = 33.33 \ ml[/tex]
Therefore, volume required is 33.33 ml .
Today we are going to perform a titration. What is an acid-alkali titration?
a) A measurement apparatus
b) An analytic method
c) A chemical reaction
LABSTER
Answer:
A chemical reaction
Explanation:
You're doing acid-alkali. Acid is like a ph.
Titration is a method used to prepare salts if the reactants are soluble. Concentration and volumes of reactants can be calculated from titrations. The concentration of an acid or alkali can be calculated by carrying out an experiment called a titration.
We have that for the Question "Today we are going to perform a titration. What is an acid-alkali titration?" it can be said that
From the question we are told
Today we are going to perform a titration. What is an acid-alkali titration?
a) A measurement apparatus
b) An analytic method
c) A chemical reaction
Generally
acid-alkali titration is a popular chemical reaction that is used to obtain salts and this method is also used to determine many other variables of the reactants
Therefore
An acid-alkali titration is a
chemical reaction
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as a sample of water is heated, the kinetic energy of its molecules increases then, the energy is used to overcome the attractions between the molecules so that they are no longer help close together. Which sections of the heating curve illustrate this process
The sections of the heating curve illustrate this process Section A followed by B. Therefore, option D is correct.
What is the heating curve ?The term heating curve is defined as the graphical representation of the correlation between heat input and the temperature of a substance.
At section, A solid Ice at temperature 0°C can heat for about 10 mins and all the energy generated from heating up the ice is used to split the bonds which binds the ice together as a solid.
At Section, B the liquid water at 100°C covert to vapor because the heat energy required here split the bond between the water molecules then they are move in random directions as vapor.
Thus, option D is correct.
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Your question is incomplete, probably your question was
As a sample of water is heated, the energy is used to overcome the attractions between the molecules so that they are no longer held close together and can move in random directions. Then, the kinetic energy of its molecules increases. Which sections of the heating curve illustrate this process?
As a sample of water is heated, the energy is - 1
Image is attach below
What is the name of the charge that orbits the nucleus called?
Answer:
Electrons
Explanation:
"An electron is a negatively charged particle that orbits the nucleus of an atom."
"Electrons are negatively charged particles arranged in orbits around the nucleus of an atom"
How many Liters of a 4.5 M HCL solution can be prepared by using 250.0 mL of a 12.0 M HCl solution?
Answer:
0.667 L
Explanation:
From the question given above, the following data were obtained:
Initial volume (V₁) = 250 mL
Initial concentration (C₁) = 12 M
Final concentration (C₂) = 4.5 M
Final volume (V₂) =?
The final volume of the solution can be obtained by using the dilution formula as illustrated below:
C₁V₁ = C₂V₂
12 × 250 = 4.5 × V₂
3000 = 4.5 × V₂
Divide both side by 4.5
V₂ = 3000 / 4.5
V₂ = 667 mL
Finally, we shall convert 667 mL to L. This can be obtained as follow:
1000 mL = 1 L
Therefore,
667 mL = 667 mL × 1 L / 1000 mL
667 mL = 0.667 L
Thus, the volume of the solution prepared is 0.667 L
If 160 grams of a 200-gram sample of gold-198 decay in 6.25 days, what is the half-life of gold-198?
The half-life of gold-198 is 2.77 days
What is half-life of gold-198?Gold-198 decays with a half-life of 2.7 days to stable mercury-198 by emission of ß particles of maximum energy 0.960 Mev and Y -rays of energies 0.412, 0.68 and 1.09 Mev as shown schematically in In a gold grain, the thickness of the enveloping sheath of platinum is such that the ß particles: The amount of time it takes to disintegrate by half an initial amount. For a given reaction, a reactant's half-life t1/2 is the time it takes for its concentration to reach a value which is the arithmetic mean of its initial and final (equilibrium) value.Since Au-198 is 200 g originally and it decays to 160 g, so 40g leftthe fraction decay is 40/200 = 0.2the time base is 6.25 daysln0.2/6.25 = -0.25k=ln2/half life therefore half-life = ln2/k = ln2/0.25half life = 2.77 daysSo, half life of gold is 2.77 daysTo learn more about half-life of gold-198 refers to:
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determine the mass of IF5 in a 15.88 L sample at 378 K and 0.935 atm
The mass of [tex]IF_5[/tex] that would be in a 15.88 L sample at 378 K and 0.935 will be 106.51 grams.
Ideal gas problemThe problem can be solved by first using the ideal gas equation to know the number of moles of the gas that is present.
PV = nRT
P = 0.935, V = 15.88 L, T = 378 K, R = 0.082
Making n the subject of the formula:
n = PV/RT
= (0.935x15.88)/(0.082x378)
= 0.48 moles of the gas
Recall that, mass = mole x molar mass
The molar mass of [tex]IF_5[/tex] is 221.89 g/mol
Mass of 0.48 moles [tex]IF_5[/tex] = 0.48 x 221.89
= 106.51 grams
In other words, the mass of [tex]IF_5[/tex] that would be in a 15.88 L sample at 378 K and 0.935 is 106.51 grams.
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organic compounds on basis of carbon skeleton
Answer:
Acyclic or Open-chain compounds. Cyclic or Closed-chain compounds.
You pour some hot water into a metal cup. After a minute,
you notice that the handle of the cup has become hot.
Explain, using your knowledge of heat transfer, why the
handle of the cup heats up. How would you design the cup so
that the handle does not heat up?
Heat transfer is the movement of thermal energy from a temperature that is higher to one that is lower.
Thermoenergy: What is it?The energy that exists in a system and controls its temperature is known as thermal energy. Heat is thermal energy in motion. Thermodynamics is a comprehensive field of physics that examines how heat and work are transferred between diverse systems.
Energy of what kind is thermal energy?The energy that results from atoms and molecules moving around within a substance is known as thermal energy, often known as heat. When these particles move more quickly, heat is produced. Geothermal energy is the earth's heat energy. Energy held within motion is referred to as motion energy.
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How many grams are in 3.4 moles of Sulfur
Answer:
109.02 grams
Explanation:
Multiply the molar mass of sulfur by the moles: 3.4 * 32.065 = 109.02 grams
What is atomic radius?
Answer:
The atomic radius of a chemical element is the measure of the size of its atoms, usually the mean or typical distance from the centre of the nucleus to the boundary of surrounding shells of electrons
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Use the data in the table below to calculate the heat of vaporization (AHvap) in kJ/mol of pinene.
Vapor Pressure
(torr)
760
515
340
218
135
Temperature
(K)
429
415
401
387
373
kJ/mol
Use the value of AHyap determined in Part 1 to calculate the vapor pressure of pinene (in torr) at room temperature (23°C)
760
torr
Answer:
41 kJ/mol4 torrExplanation:
Given pinene has a (temperature, vapor pressure) relation (K, torr) = {(373, 135), (429, 760)}, you want the heat of vaporization in kJ/mol and the vapor pressure at room temperature (23 °C).
Clausius–Clapeyron EquationThe Clausius–Clapeyron equation can be used to find the heat of vaporization:
[tex]\ln{P}=-\dfrac{\Delta H_{\text{vap}}}{R}\left(\dfrac{1}{T}\right)+C[/tex]
Solving for ∆H, we find ...
[tex]\Delta H_{\text{vap}}=-\dfrac{R\cdot\ln{\dfrac{P_1}{P_2}}}{\dfrac{1}{T_1}-\dfrac{1}{T_2}}\\\\\\\Delta H_{\text{vap}}=-\dfrac{8.314\cdot\ln{\dfrac{760}{135}}}{\dfrac{1}{429}-\dfrac{1}{373}}\approx 41052.8[/tex]
The heat of vaporization of pinene is about 41 kJ/mol.
Vapor pressureRearranging the above equation to give P1, we have ...
[tex]\ln{\dfrac{P_1}{P_2}}=-\dfrac{\Delta H_\text{vap}}{R}\left(\dfrac{1}{T_1}-\dfrac{1}{T_2}\right) \\\\\\P_1=P_2\cdot e^{-\frac{\Delta H_\text{vap}}{R}\left(T_1^{-1}-T_2^{-1})}[/tex]
Using the same P2 and T2 as above, we find the vapor pressure at room temperature (296.15 K) to be ...
P1 ≈ 4.349 . . . . . torr
The vapor pressure of pinene at room temperature is about 4 torr.
Compound composed of sulfur and fluorine is found to contain 45.77% by mass of sulfur is the molar mass of the compound is 140.12 g per mole what is its molecular formula
Answer: Molecular formula is S2F4
Explanation: Assume mass of sample is 100 g.
Then mass of S is 45.77 g and amount of substance is
n = m/M = 45.77 g / 32.07 g/mol = 1.427 mol
MAss of F is 54.23 g and n = 54.23 g / 19 g/mol = 2.854
n(S( : n(F) = 1.427 : 2.854 | : 1.427 gives proportion
n(S) : n(F) = 1:2 , empirical formula is also (SF2)x
Now M(SF2) = 32.07 + 2·19 = 70.07 g/mol
x = 140.12 / 70.07 = 2