What happens when hydrogen gas is passed over heated copper oxide $(CuO)$?

What happens when zinc granules are treated with dilute solutions of $NaCl$ and $NaOH$? Also,write the chemical equations if a reaction occurs.

Describe an activity to show a decomposition reaction in which light is used to decompose a reactant. Write the chemical equation of the reaction and state its one use.

$A$ small amount of quicklime is added to water in a beaker.
$(a)$ Name and define the type of reaction that has taken place.
$(b)$ Write the balanced chemical equation for the above reaction. Write the chemical name of the product obtained.
$(c)$ State two observations that you will make in the reaction.

Write the chemical equation of the reaction with an example in which a change in temperature takes place.

Which of the following statements about the given reaction are correct?
$3 Fe (s) + 4 H_2 O (g) \rightarrow Fe_3 O_4 (s) + 4 H_2 (g)$
$(i)$ Iron metal is getting oxidised
$(ii)$ Water is getting reduced
$(iii)$ Water is acting as reducing agent
$(iv)$ Water is acting as oxidising agent