Equilibria (triple) quiz

1. What is meant by the term endothermic?

A reaction in which heat energy is given out (surroundings get hotter)

A reaction which will only be spontaneous at cold temperatures (below 0⁰C)

A reaction which will only be spontaneous at warm temperatures (above 100⁰C)

A reaction in which heat energy is taken in (surroundings get colder)

Question 1 of 15

2. What colour is anhydrous copper (II) sulfate?

White

Purple

Blue

Cream

Question 2 of 15

3. Ammonia and hydrogen chloride react together in a reversible reaction to produce a white solid. What are the word and symbol equations?

ammonia + hydrogen chloride ⇌ ammonium chloride NH₃ + HCl ⇌ NH₄Cl

ammonia + hydrogen chloride ⇌ ammonium chloride + water NH₃ + HCl ⇌ NH₄Cl + H₂O

ammonia + hydrogen chloride ⇌ ammonium chloride + hydrogen 2NH₃ + 2HCl ⇌ 2NH₃Cl + H₂

ammonia + hydrogen chloride ⇌ ammonium hydrochloride NH₃ + HCl ⇌ NH₃ClH

Question 3 of 15

4. Explain the effects of increasing the surface area of a solid on the rate of a reaction in terms of particle collision theory

1) more particles exposed 2) more frequent collisions 3) decrease rate of reaction

1) more particles exposed 2) less frequent collisions 3) increase rate of reaction

1) more particles exposed 2) more frequent collisions 3) increase rate of reaction

1) more particles exposed 2) less frequent collisions 3) decrease rate of reaction

Question 4 of 15

5. Why a catalyst does not affect the position of equilibrium in a reversible reaction?

A catalyst has no effect on a forward or backward reactions if it is in dynamic equilibrium

A catalyst reduces the activation energy, and is not used up

A reaction in dynamic equilibrium already has the lowest possible activation energy

If a reversible reaction is in dynamic equilibrium, a catalyst increases the rate of the forward reaction and the rate of the backward reaction by the same amount, so the position of equilibrium is unaffected

Question 5 of 15

6. What is a catalyst?

A substance that speeds up a chemical reaction but is chemically unchanged at the end of the reaction

A substance that helps dissolve insoluble reagents to speed up the rate of reaction

A substance that speeds up a chemical reaction but is used up as the reaction proceeds

A substance that slows down a chemical reaction but is chemically unchanged at the end of the reaction

Question 6 of 15

7. What happens if two particles collide with less than the activation energy

The reaction only goes partway

The particles fuse together

The reaction still occurs but very slowly

No reaction

Question 7 of 15

8. State two features of a reaction that is in dynamic equilibrium

1) The rate of the forward reaction is equal to the rate of the backward reaction. 2) There is no overall change in concentrations.

1) The rate of the forward reaction is greater than the rate of the backward reaction. 2) there is no overall change in concentrations

1) The equilibrium is on the right hand side producing a greater concentration of product than reactant. 2) The rate of the forward reaction is equal to the rate of the backward reaction

1) The concentrations of products and reactants are equal. 2) the rate of the forward reaction is equal to the rate of the backward reaction

Question 8 of 15

9. Gas particles move at a speed of several hundred metres per second at room temperature. Explain why gases take several minutes to diffuse across a room

Gas particles collide with air particles and move in only one direction

Gas particles travel very slowly

Gas particles are lazy and do not want to reach the other side of the room

Gas particles collide with air particles and move in random directions

Question 9 of 15

10. State the expression for calculating % yield.

% yield = (theroretical amount of products/actual amount of products)

% yield = (theroretical amount of products/actual amount of products) x 100

% yield = (actual amount of products/theoretical amount of products) x 100

% yield = (actual amount of products/theoretical amount of products)

Question 10 of 15

11. In a sealed container, a reversible reaction can reach a state of ______________________________

Static equilibrium

Variable equilibrium

Dynamic equilibrium

Constant equilibrium

Question 11 of 15

12. In a calorimetry experiment to investigate the heat energy released by the combustion of ethanol, why should the water in the calorimeter be stirred?

To prevent the water from evaporating

To allow the heat to spread evenly through the copper container

To ensure the container does not get too hot

To ensure the heat energy is mixed evenly throughout all the water

Question 12 of 15

13. What will happen to the yield of C when the temperature is increased? Give a reason for your prediction. A (g) + B (g) ⇋ C (g) (+∆H)

Decreases because the backward reaction is endothermic

Decreases because the backward reaction is exothermic

Increases because the forward reaction is endothermic

Increases because the forward reaction is exothermic

Question 13 of 15

14. What does the symbol ⇌ mean?

Variable oxidation state

Reversible reaction

Equal amounts of reactants and products

A reaction that requires a catalyst

Question 14 of 15

15. What does this diagram represent?

Energy level diagram for an endothermic reaction

Reaction profile for an exothermic reaction

Reaction profile for an endothermic reaction

Energy level diagram for an exothermic reaction

Question 15 of 15

Equilibria (triple) quiz

Equilibria (triple) quiz

Related Posts:

Share This Story, Choose Your Platform!