A chemical reaction between substances and oxygen in which CO2, heat and light is generated, is called ……..reaction.
a) decomposition
b) displacement
c) addition
d) combustion
Burning of coal and methane is example of…
a) decomposition
b) displacement
c) addition
d) combustion
Energy Changes In Chemical Reactions:
The energy change in a chemical reaction is due to the difference in the amounts of stored chemical energy between the products and the reactants. This stored chemical energy, or heat content, of the system is known as its enthalpy.
On the basis of energy changes, how many types of chemical reactions are there?
a) two
b) three
c) three
d) four
Explanation:1. Exothermic reaction and
2. Endothermic reaction
Chemical reactions involve…….changes.
a) energy
b) volume
c) phase
d) mass
What happens when copper sulphate and sodium hydroxide solutions are mixed?
a) the beaker became warm
b) the beaker became cold
c) the beaker became hydrated d) none of these
