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A student used the apparatus in Figure 13 to investigate the rate of the reaction between a metal and dilute hydrochloric acid - Edexcel - GCSE Chemistry - Question 8 - 2022 - Paper 1
Question 8
A student used the apparatus in Figure 13 to investigate the rate of the reaction between a metal and dilute hydrochloric acid. Pieces of the metal were placed in d... show full transcript
Worked Solution & Example Answer:A student used the apparatus in Figure 13 to investigate the rate of the reaction between a metal and dilute hydrochloric acid - Edexcel - GCSE Chemistry - Question 8 - 2022 - Paper 1
Step 1
Name a piece of apparatus that would be better to measure the volume of gas produced, instead of the 250 cm³ measuring cylinder.
Answer
A gas syringe.
Reason: A gas syringe provides a more accurate measurement of small volumes of gas and can be used to measure the gas directly without loss of gas to the atmosphere.
Step 2
Calculate the mean rate of production of hydrogen over the first 90 seconds, in cm³ per second.
Answer
To find the mean rate of production of hydrogen over the first 90 seconds, we first need to read the volume of gas produced from the graph for the first 90 seconds. Suppose the volume recorded is 30 cm³. Therefore,
Mean rate =
rac{volume ext{ } of ext{ } gas}{time} = rac{30 ext{ } cm³}{90 ext{ } seconds} = rac{1}{3} ext{ } cm³/s ext{ or } 0.33 ext{ } cm³/s.
Step 3
Step 4
Explain why the rate of reaction increases when the concentration of acid is increased.
Answer
The rate of reaction increases with increasing concentration of acid due to a higher number of reactant particles per unit volume. This leads to more frequent collisions between the acid particles and the metal, thereby increasing the likelihood of successful reactions.
Step 5
Step 6
Describe how the student can make small and medium sized marble chips from large chips.
Answer
The student can break the large marble chips using a hammer or a mortar and pestle to achieve smaller pieces. To ensure some chips are medium-sized, mix the smaller chips with the larger pieces during the crushing process.