1 Blessy reacts each of the metals calcium, magnesium and iron
with dilute hydrochloric acid. (b) What measurements does Blessy take to find out which
She wants to find out which reaction releases the most heat. reaction releases the most heat?
(a) Blessy decides to use 20 cm3 of dilute hydrochloric acid
and 0.1 g of each metal.
Explain why she uses the same volume of dilute
hydrochloric acid each time.
2 Aiko reacts iron with dilute sulfuric acid.
She takes the temperature of the dilute sulfuric acid before she (b) Iron reacts with sulfuric acid.
adds the iron. Iron sulfate and hydrogen are made.
She takes the temperature of the reaction mixture at the end of Write down the word equation for this reaction.
the reaction.
Look at her results.
(a) Write down the type of reaction between iron and dilute
sulfuric acid.
Choose from the list.
Explain your answer.
3 Blessy reacts two solutions together.
(c) Blessy repeats her experiment with different solutions.
She measures the temperature at the start and at the end
of each reaction.
Look at her results.
She notices that the temperature increases during the reaction.
Reaction C gives out the most energy.
(a) Write down the name of the type of reaction that gives an Explain how you can tell from the results.
increase in temperature.
(b) Write down the name of the equipment that Blessy uses
to measure temperature.
4 Mia makes two salts.
She mixes 20 cm3 of an acid with 1 g of a solid in a beaker.
She repeats this with a different solid and a different acid. (b) Mia wants to know which reaction has the largest energy
She notices that one reaction mixture warms up and the other change.
cools down. Suggest what Mia does to find out which reaction has the
largest energy change.
(a) Zinc reacts with sulfuric acid.
Zinc sulfate and hydrogen are made. (c) The reaction between sodium carbonate and ethanoic
Write the word equation for this reaction. acid cools down.
What is the name given to this type of chemical reaction?
5 A small piece of magnesium ribbon is added to dilute sulfuric
acid in a test tube. (c) The reaction is exothermic.
What happens to the temperature of the acid during the
Hydrogen gas is produced. reaction?
(a) State two observations that can be seen during the
reaction.
(d) The word equation for the reaction is shown below.
(b) What test can be used to confirm the identity of the gas? What should X and Y be in the equation?
Tick the correct box.
X: .......................................
Glowing splint test
Y: .......................................
Limewater test
Litmus paper test
Lighted splint test
6 Safia investigates the reaction between magnesium ribbon and
dilute sulfuric acid. Safia then calculates the temperature change for each reaction.
In each experiment Safia uses 25 cm3 of sulfuric acid.
She records the temperature of the acid and then adds some (a) Put her results, including the temperature changes, into a
magnesium ribbon. table.
When the magnesium has finished reacting she records the
temperature of the acid again.
Safia does this experiment six times.
(b) One set of readings is an anomalous result.
Each time she uses a different length of magnesium ribbon.
Which set?
Look at Safia’s results.
(c) The reaction between magnesium and sulfuric acid
releases energy.
What is the name given to a reaction that releases energy?
7 A student measures the maximum temperature change when five
different solids, P, Q, R, S and T are dissolved separately in water. (c) The results are shown below.
The experiment set-up is as below.
(a) The student stirs the mixture as each solid is added.
Why?
(i) Which solid released the most energy?
(b) What are two factors that should be kept the same to
make sure the experiment is fair? (ii) Which solids gave an endothermic energy change
when dissolved in water?
