10 minutes maximum! Can you do it in 5?

1. The rate of a chemical reaction as the reaction proceeds.

2. Which of the following factors would increase the rate of a reaction?

(I) powdering a solid
(II) increasing the temperature of a solution
(III) decreasing the concentration of solution

  • A. (I) and (II)
  • B. (I) and (III)
  • C. (II) and (III)
  • D. (I), (II) and (III)
3. Increasing the pressure of a mixture of hydrogen and oxygen gases would ...
  • A. decrease the rate of reaction
  • B. increase the rate of reaction
  • C. not affect the rate of reaction
  • D. increase the volume of the mixture

Q4-6.
A student investigated the effect of increasing the temperature on the rate of reaction between magnesium and hydrochloric acid.

The equation for this reaction is:

Mg(s) + 2HCl(aq) → MgCl2(aq) + H2(g)

4. To ensure a fair test the student should use the same ...
  • A.  temperature, mass of magnesium and concentration of acid
  • B.  temperature, mass of magnesium and volume of acid
  • C.  mass of magnesium, concentration and volume of acid
  • D.  mass of magnesium, volume of acid and temperature
5. The initial rate of reaction increased with temperature. The initial rate could be decreased by ...
  • A. using powdered magnesium
  • B. decreasing acid volume                              
  • C. increasing acid volume
  • D. decreasing acid concentration
6. The rate of this reaction could be determined by recording the ...
  • A. volume of gas at regular time intervals
  • B. time for the magnesium to disappear
  • C. time to collect a fixed volume of gas
  • D. all of the above

 

Q7-8.
In the reaction between marble chips and hydrochloric acid, one way to increase the rate of reaction is to increase the acid concentration.

CaCO3(s) + 2HCl(aq) → CaCl2(aq) + H2O(l) + CO2(g)

 

7. Rate can also be increased by ...

  • A. increasing temperature
  • B. crushing the marble chips
  • C. adding a suitable catalyst
  • D. all of the above
8. The best reason for the reaction rate increasing with concentration is ...
  • A. …more reactant particles which increases the frequency of collisions
  • B. …more reactant particles which increases the energy of the collisions
  • C. …more reactant particles per unit volume which increases the frequency of collisions
  • D. …more reactant particles per unit volume which increases the energy of the collisions

 

Q9-10.
The following graph was obtained by reacting excess magnesium powder with 50cm3 0.1mol/dm3 hydrochloric acid at 250C.
The volume of gas produced was measured over a 3 minute period:

rate of reaction graph

 
9. A steeper graph which produces the same final volume of gas would be obtained by ...
  • A. using the same mass of magnesium ribbon instead of powder
  • B. using the same volume of a more concentrated acid
  • C. increasing the temperature
  • D. decreasing the temperature
10. Repeating the experiment with 100cm3 of 0.1mol/dm3 hydrochloric acid at 250C would produce a graph which ...
  • A. is steeper and finishes at the same final volume
  • B. is steeper but produces a greater final volume
  • C. has the same gradient and finishes at the same final volume
  • D. has the same gradient but produces a greater final volume