Question

What happens when the mixture of red phosphorus and iodine is heated with water.

Answer 1

Hint: When two or more reactants undergo a chemical change, then new products are formed. Phosphorus exists in allotropic forms as red, white and black. Red phosphorus is one of these forms that has formula ${{P}_{4}}$. Iodine is a solid and exists as a diatomic molecule. Both of them first combine and then react with water when heated.

Complete answer:
We have been given to tell the outcome when a mixture of red phosphorus and iodine is heated with water.
Red phosphorus is an allotrope of phosphorus that exists as ${{P}_{4}}$ in its natural form of P molecule. Iodine is a solid that has a formula ${{I}_{2}}$. Initially red phosphorus and iodine are combined. The product of their combination is then heated with water.
So, the mixture of red phosphorus and iodine is formed as:
$2P+3{{I}_{2}}\to 2P{{I}_{3}}$
This mixture is heated in the presence of water that produces phosphorous acid and hydrogen iodide. The reaction is:
$2P{{I}_{3}}+6{{H}_{2}}O\to 2{{H}_{3}}P{{O}_{3}}+6HI$
Hence, when a mixture of red phosphorus and iodine is heated with water then phosphorus acid and hydrogen iodide are formed.

Note:
When two reactants combine together to form a single product, then the reaction is a combination reaction. Red phosphorus is red in color and more stable than white phosphorus as it has less activity. Red phosphorus in its normal state does not dissolve in water, therefore it is heated and then it forms the desired products.