Balanced equation:
Na2CO3 + H2SO4 →
Na2SO4 + H2O
We Know:
Two substances neutralize each other when the molar ratio 1
: 1.
Molar mass of Na2CO3 = 106 g/mol
Amount of Na2CO3 taken = 2.16 g
Moles in 2.16 g Na2CO3 = (2.16 g) / (106
g/mol) = 0.0204 mol
Moles of H2SO4 needed to neutralize
0.0204 mol of Na2CO3 = 0.0204 mol
Concentration of H2SO4 solution = 0.1
N
= (0.1/2) M = 0.05 M
Moles of H2SO4 in 1000 mL (1 L) = 0.05
Moles of H2SO4 in 400 mL solution
= 0.05 × 400/1000 = 0.02 mol
Total moles of H2SO4 needed = 0.0204
Further amount of H2SO4 needed
= 0.0204 mol - 0.02 mol
= 0.0004 mol
Molar mass of H2SO4 = 98 g/mol
Mass of 0.0004 mol of H2SO4 = 98 g ×
0.0004
= 0.0392 g
Mass of H2SO4 further needed = 0.0392 gram