Question

Complete the reaction below and balance it.

${\mathrm{K}}_2\mathrm{O}+{\mathrm{H}}_2\mathrm{O}\to$

Answer 1

Answer:

Reaction between Potassium oxide(${\mathrm{K}}_2\mathrm{O}$) and water (${\mathrm{H}}_2\mathrm{O}$) results in the formation of potassium hydroxide($\mathrm{KOH}$).

Chemical equation:

${\mathrm{K}}_2\mathrm{O}\left(\mathrm{s}\right)+{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)\to 2\mathrm{KOH}\left(\mathrm{l}\right)$

General steps for balancing equation

Step 1

Let us first write word equation for the reaction.

Potassium oxide + Water $\to$Potassium hydroxide

Step 2

Write the chemical equation for the reaction between potassium oxide and water.

Step 3

Count the number of times an element is occurring on both LHS and RHS in this equation.

Components	Reactant	Product
Hydrogen	2	1
Oxygen	2	1
Potassium	2	1

This is an unbalanced equation.

Step 4

• To balance a chemical equation, choose a reactant or a product that has the maximum no of atoms in it.
• In that compound, select an element which has the maximum number of atoms in it.

In the above equation we shall select $\mathrm{KOH}$ i.e. potassium hydroxide and the element Oxygen in it.

To balance the Oxygen atoms, let us multiply potassium hydroxide by 2 on right-hand side. The equation can now be expressed as

Components	Reactant	Product
Hydrogen	1*2	2
Oxygen	1*2	2
Potassium	1*2	2

Step 5

Now there is 2 Hydrogen atoms ,2 Oxygen atoms, 2 Potassium atoms on both side of the equation. Hence the equation is balanced.

The balanced equation for the reaction is :

${\mathrm{K}}_2\mathrm{O}\left(\mathrm{s}\right)+{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)\to 2\mathrm{KOH}\left(\mathrm{aq}\right)$