Question

Which of the substances reacts with water?
A. Chlorine
B. Phosphorus trichloride
C. Silicon tetrachloride
D. Tetrachloromethane

Answer 1

Hint: To solve this write the reaction of each of them with the water and then whether it reacts with water to form a product or not. The one which will not react with water because when we add water in it it forms a separate layer underneath the layer of water. More than option is correct.

Complete step by step answer:
Let us discuss each option one by one:
(a) Chlorine
Now, when a chlorine $C{{l}_{2}}$ gas tends to reacts with water it is hydrolyzed rapidly to produce hypochlorous acid $(HOCl)$ and after that this hypochlorous acid dissociated into hypochlorite ion$(OC{{l}^{-}})$ and the hydrogen ion \[({{H}^{+}})\]. And due to the production of hydrogen ion water will become more acidic i.e. the pH of the water will decrease. So, the reaction between the chlorine and water is given as:
\[Cl+{{H}_{2}}O\to HOCl\]
Hence chlorine reacts with water.

(b) Phosphorus trichloride
Phosphorus trichloride $(PC{{l}_{3}})$ is a type of a colorless fuming liquids which reacts violently with the water to yield the product as phosphoric acid $({{H}_{3}}P{{O}_{3}})$ and hydrogen chloride (HCl) and the reaction is given as:
\[PC{{l}_{3}}+{{H}_{2}}O\to {{H}_{3}}P{{O}_{3}}+HCl\]

(C) Silicon tetrachloride
Silicon tetrachloride $(SiC{{l}_{4}})$ also reacts violently with the water to give the product as white solid silicon dioxide $(S{{O}_{2}})$ and the steamy fumes of HCl. Therefore $SiC{{l}_{4}}$ fumes in the most air because it tends to react with the water vapor present in the air. The reaction is given as:
\[SiC{{l}_{4}}+{{H}_{2}}O\to Si{{O}_{2}}+HCl\]

(D) Tetrachloromethane
Tetrachloromethane which is also known as carbon tetrachloride $(CC{{l}_{4}})$ do not react with water because when $(CC{{l}_{4}})$ added to water forms a separate layer of $(CC{{l}_{4}})$ underneath the water.
Therefore Chlorine, Phosphorus trichloride and Silicon tetrachloride react with water.
So, the correct answer is “Option A, B and C”.

Note: Silicon tetrachloride and carbon tetrachloride both are the compounds of tetrachloride but silicon reacts with water because the size of the silicon is larger than the carbon, therefore it has more room for water molecules to attack. Phosphorus trichloride and its byproduct are highly corrosive to skin eyes and mucous membrane.