Science Form 3 Chapter 5 (Thermochemistry)

Which reaction explains about exothermic reaction?

• Heat is absorbed from the surroundings

• Surrounding temperature increases

• Heat energy is changed to chemical energy

• Thermometer reading decreases

Which statement is correct about endothermic reaction?

• Heat is released

• Thermometer reading increases

• Surrounding temperature increases

• Breaks the chemical bonds of the reactant

Respiration is an exothermic reaction.

Which of the following explains about the process?

• Release heat to the environment

• The chemical bond in glucose is broken down

• Heat energy is changed to chemical energy

• Forming water as byproduct

Which process does not involve the release of heat energy?

• The combustion of petrol

• The formation of ice

• Volcano eruption

• Melting of butter

The diagram shows the bread dough is put into an oven to be baked.

Which statements are correct about the baking process?

Choose more than one answer.

• Endothermic reaction occurs

• The heat from the oven is absorbed by the dough

• Thermal equilibrium achieved when the bread is cooked

• The formation of new substance did not occur

Tags

NGSS.2-PS1-4

The diagram shows sublimation process that occurs in dry ice.

This process is endothermic. Why?

• New substance is formed

• There is a conversion of energy

• Dry ice absorbs heat from surroundings

• The water vapour formed is very cold.

Endothermic is a reaction that absorbs heat.

• TRUE

• FALSE

Breaking the chemical bond releases energy.

• TRUE

• FALSE

What happens when heat energy is absorbed?

• Bond formation occurs

• Exothermic reaction

• Bond breakage occurs

• No change occurred

The diagram shows the set - up of apparatus for an experiment.

Which of the following statements is true about the reaction that occurred in the experiment?

• Temperature of water increases

• Heat energy is absorbed from the environment

• Exothermic reaction occurs

• Heat energy is released during reaction