Question

Balance the following equation stepwise.

H₂SO_4(aq) + NaOH_(aq) → Na₂SO_4(aq) + H₂O_(I)

Answer 1

Step 1:

Rewrite the given equation as it is

H₂SO_4(aq) + NaO_(aq) → Na₂SO_4(aq) + H₂O_(I)

Step 2:

write the number of atoms of each element in the unbalanced equation on both sides of the equation.

Element	Number of atoms in reactants	Number of atoms in products
Na	1	2
S	1	1
O	5	5
H	3	2

The number of oxygen atoms involved in different compounds on both sides (reactants and products) are equal. Therefore, balance the number of atoms of the second element, sodium.

Step 3:

To balance the number of sodium atoms:

Number of atoms of sodium	In reactants	In products
To begin with	1 (in NaOH)	2 (in Na2SO4)
To balance	1 × 2	2

To equalise the number of sodium atoms, we use 2 as the factor of NaOH in the reactants. Now, the partly balanced equation becomes as follows

H₂SO₄ + 2NaOH → Na₂SO₄ + H₂O

Step 4:

Now, balance the number of hydrogen atoms:

Number of atoms of hydrogen	In reactants	In products
To begin wit	(in H2SO4) 2 (in NaOH)	2 (in H2O)
To balance	4	2 × 2

To equalise the number of hydrogen atoms, we use 2 as the factor or H₂O in the products. The equation then becomes

H₂SO₄ + 2NaOH → Na₂SO₄ + H₂O

Now, count the atoms of each element on both sides of the equation. The number of atoms on both sides are equal. Hence, the balanced equation is

H₂SO₄ + 2NaOH → Na₂SO₄ + H₂O

Now indicate the physical states of the reactants and the products.

H₂SO_4(aq) + 2NaOH_(aq) → Na₂SO_4(aq) + 2H₂O_(I)