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Chemistry AQA GCSE: Rates

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1. Which reaction between marble chips and acid would be fastest?
  • A.   5g of powdered marble and hot acid
  • B.   5g of powdered marble and cold acid
  • C.   5g of marble chips and hot acid
  • D.   5g of marble chips and cold acid

2. The diagram shows the apparatus used to measure the rate of a chemical reaction.

conical flask on electronic balance

For which of the following reactions can the rate be measured using this apparatus?

I. NaOH  +  HCl    NaCl  +  H2O
II. CaCO3  +  2HCl    CaCl2  +  H2O   +  CO2
III. 2H2O2    2 H2O   +  O2
 
  • A.   all of them
  • B.   I and II only
  • C.   I and III only
  • D.   II and III only
3. A student investigated the rate of reaction between zinc and excess sulfuric acid.

The graph shows the results of two experiments, X and Y.

 

rates of reaction graph 1

Which one of the following would explain the difference between X and Y?

 
  • A.   Y was carried out at a higher temperature
  • B.   Y was carried out using less concentrated acid
  • C.   X had a catalyst added
  • D.   X was carried out using powdered zinc

4. Which changes decrease the rate of reaction between calcium carbonate and dilute hydrochloric acid?

I. Decrease the temperature
II. Decrease the concentration of acid
III. Decrease the size of the calcium carbonate pieces
 
  • A.   I, II and III
  • B.   I and II only
  • C.   I and III only
  • D.   II and III only
5. Which of the following is NOT true about catalysts?
  • A.   Catalysts are not chemically changed in the reaction
  • B.   Catalysts speed up a reaction
  • C.   Catalysts provide an alternative path of lower activation energy
  • D.   Catalysts do not take part in the reaction

Q6-7:
A student investigated the rate of reaction between magnesium and acid by adding a 10cm piece of magnesium ribbon to 50cm3 of dilute hydrochloric acid and measuring the volume of hydrogen produced at regular time intervals.
Her results are plotted on the graph below:

Rate of reaction graph 1

6. The mean rate of reaction up to the time the reaction is complete is ...

  • A.   0.40 cm3/s
  • B.   0.60 cm3/s
  • C.   1.67 cm3/s
  • D.   2.50 cm3/s

7. State and explain the effect on the rate of reaction of cutting the magnesium ribbon into very small pieces in terms of surface to volume ratio.

  Rate of Reaction ..because the surface to volume ratio has..
A decreases decreased
B decreases increased
C increases decreased
D increases increased

8. Which of the following statements about catalysts are true? A catalyst ...

     I.      provides an alternative pathway with lower activation energy
   II.      provides an alternative pathway with a lower energy change
 III.      is chemically unchanged at the end of the reaction
 
  • A.   I and II
  • B.   I and III
  • C.   II and III
  • D.   all of them

9. A 1.0 mol/dm3 solution of hydrochloric acid reacts more slowly with marble chips than the same volume of a 2.0 mol/dm3 solution.

Which of the following is the correct reason for this observation?

  1.0 mol/dm3 acid contains.. Collisions between reactants are..
A less particles per cm3 more frequent with 1.0 mol/dm3 acid
B less particles per cm3 less frequent with 1.0 mol/dm3 acid
C more particles per cm3 more frequent with 1.0 mol/dm3 acid
D more particles per cm3 less frequent with 1.0 mol/dm3 acid

10. A student investigates the effect of four solids, A,B,C and D, on the decomposition of hydrogen peroxide using the following apparatus:

gas syringe experiment

He adds 1g of solid to 25cm3 of hydrogen peroxide solution and records the time taken to collect 20cm3 of oxygen. He then filters off, dries and weighs the solid.
Which solid labelled A to D acted as the best catalyst according to the following results?

  Time taken to collect 20cm3 oxygen (s) Mass of solid after experiment (g)
A 106 0.8
B 58 1
C 9 0.7
D 24 1