9-chemical energetics(energy changes)

Exothermic reaction ___________energy to the surroundings.

Endothermic reaction ___________energy to the surroundings.

What happens to the temperature of surroundings during exothermic reaction ?

• increases

• decreases

What happens to the temperature of surroundings during endothermic reaction ?

• increases

• decreases

In an exothermic reaction, the energy of the products is …………………. than the energy of the reactants.

• lower
• higher

The enthalpy change of endothermic reaction is ____________.

• positive

• negative

The electrolysis of seawater is endothermic. Water breaks down to form hydrogen gas and oxygen gas. 2H2O --> 2H2 + O2

Draw the energy profile diagram for this process. Clearly label reactants, products, enthalpy change and activation energy.

Which TWO of the following reactions are endothermic?

• neutralisation

• electrolysis

• combustion

• photosynthesis

• respiration

Bond breaking is _____________.

• exothermic

• endothermic

bond forming releases energy. True or false?

• true

• false