C5

Question 1

What is an Exothermic reaction?

Answer 1

An exothermic reaction is where heat is out.
-Combustion
-Neutralisation
-Handwarmers

Question 2

What is an endothermic reaction?

Answer 2

An endothermic reaction is where heat is taken in.
-The reaction between citric acid and sodium hydrogen carbonate
-Thermal decomposition

Question 3

Practical
(Energy transfer is measured)

Answer 3

Reacting two solutions, eg acid and alkali
Place the polystyrene cup inside the glass beaker to make it more stable.
Measure an appropriate volume of each liquid, eg 25 cm3.
Place one of the liquids in a polystyrene cup.
Record the temperature of the solution.
Add the second solution and record the highest or lowest temperature obtained.
Change your
independent variable
and repeat the experiment. Your independent variable could be the concentration of one of the reactants, or the type of acid/alkali being used, or the type of metal/metal carbonate being used.

Question 4

Practical
(Energy transfer is measured)

Answer 4

Reacting two solutions, eg acid and alkali
Place the polystyrene cup inside the glass beaker to make it more stable.
Measure an appropriate volume of each liquid, eg 25 cm3.
Place one of the liquids in a polystyrene cup.
Record the temperature of the solution.
Add the second solution and record the highest or lowest temperature obtained.
Change your
independent variable
and repeat the experiment. Your independent variable could be the concentration of one of the reactants, or the type of acid/alkali being used, or the type of metal/metal carbonate being used.

Question 5

Bond breaking is a ________ process.

Answer 5

Exothermic

Question 6

Bond forming is an ___________ process.

Answer 6

Endothermic

Question 7

What is the activation energy of a reaction?

Answer 7

The minimum amount of energy the reactants need to collide with each other and react.