Question

Identify reducing and oxidising agent in the following (a) SiCl4 + H2O gives H4SiO4 + HCl

Answer 1

Answer:

In the oxidation number change method the underlying principle is that the gain in the oxidation number (number of electrons) in one reactant must be equal to the loss in the oxidation number of the other reactant.

Equation:

SiCl4 + H2O = SiO2 + HCl

Acidic medium Basic medium

Practice exercises Balanced equation

Step 1. Write down the unbalanced equation ('skeleton equation') of the chemical reaction. All reactants and products must be known. For a better result write the reaction in ionic form.

SiCl4 + H2O → SiO2 + HCl

Step 2. Separate the process into half reactions. A redox reaction is nothing but both oxidation and reduction reactions taking place simultaneously.

a) Assign oxidation numbers for each atom in the equation. Oxidation number (also called oxidation state) is a measure of the degree of oxidation of an atom in a substance (see: Rules for assigning oxidation numbers).

Si+4Cl-14 + H+12O-2 → Si+4O-22 + H+1Cl-1