| Triple only! Not for double science. |
1. When methane reacts with steam the temperature falls.
The equation for the reaction is:
CH4 + H2O ⇌ CO + 3H2
What does the symbol ⇌ represent, and is the reaction between methane and steam exothermic or endothermic? |
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meaning of ⇌ |
Reaction type |
| A |
equilibrium |
endothermic |
| B |
equilibrium |
exothermic |
| C |
Reversible reaction |
endothermic |
| D |
Reversible reaction |
exothermic |
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Q2-3:
Hydrated copper(II)sulfate can be converted to anhydrous copper(II)sulfate by heating strongly. The reaction is reversible:
CuSO4.5H2O(s) ⇌ CuSO4(s) + 5H2O(g)
The forward reaction is endothermic and absorbs 78.2 kJ/mol. |
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2. Which statement is true about the reverse reaction?
- A. It is exothermic and releases less than 78.2kJ/mol
- B. It is exothermic and releases 78.2kJ/mol
- C. It is also endothermic and absorbs more than 78.2kJ/mol
- D. It is also endothermic and absorbs 78.2kJ/mol
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3. How could the student make the reaction go in the reverse direction?
- A. cool some anhydrous copper(II)sulfate in an ice bath
- B. cool some hydrated copper(II)sulfate in an ice bath
- C. add water to anhydrous copper(II)sulfate
- D. add water to hydrated copper(II)sulfate
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4. Which one of the following statements is true about reversible reactions?
- A. All reactions are reversible under lab conditions
- B. All reversible reactions are in dynamic equilibrium
- C. All reactions go to completion under lab conditions
- D. The direction of some reversible reactions can be altered by changing the reaction conditions
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Q5+6:
Reversible reactions that are in dynamic equilibrium have two characteristics. |
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5. One of the characteristics is that the ..
- A. forward reaction is faster than the reverse reaction
- B. forward reaction is slower than the reverse reaction
- C. forward and reverse reactions both stop
- D. forward and reverse reactions occur at the same rate
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6. The second characteristic is that the ..
- A. concentrations of reactants and products are equal
- B. concentrations of reactants and products are constant
- C. concentration of reactants is less than concentration of products
- D. concentration of reactants is more than concentration of products
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| 7. Which words best fill the gaps in the following sentences?
An increase in temperature shifts the position of equilibrium in the direction of the …….(1)…… reaction.
A decrease of pressure shifts the position of equilibrium in the direction that produces ……(2)……. moles of gas |
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| |
Gap (1) |
Gap (2) |
| A |
exothermic |
more |
| B |
exothermic |
less |
| C |
endothermic |
more |
| D |
endothermic |
less |
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Q8-9:
The following reaction is used in industry during the production of sulfuric acid.
The forward reaction is exothermic.
2SO2(g) + O2(g) ⇌ 2SO3(g)
What will happen to the amount of product, SO3, formed at equilibrium if the following changes are made to the reaction conditions? |
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| 8. If the pressure is increased, the amount of product
. |
| 9. If the temperature is increased, the amount of product
. |
Q10-11:
The following reaction between carbon monoxide and hydrogen is exothermic.
CO(g) + 2H2(g) ⇌ CH3OH(g) |
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10. What happens to the rate of reaction and the position of equilibrium when the temperature is increased?
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Rate of Reaction |
Position of equilibrium |
| A |
increases |
Moves to the right |
| B |
increases |
Moves to the left |
| C |
decreases |
Moves to the right |
| D |
decreases |
Moves to the left |
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11. Which combination of temperature and pressure will give the greatest yield of methanol?
| |
Temperature |
Pressure |
| A |
high |
high |
| B |
high |
low |
| C |
low |
high |
| D |
low |
low |
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