Question

0.62 g of Na₂CO₃.H₂O is added to 100 ml. of 0.1 N sulphuric acid. Will the resulting solution be acidic, basic, or neutral? [At. wt. H = 1, C = 12, O = 16, Na = 23, S = 32].

Answer 1

Calculation of equivalents in 0.62 g of Na₂CO₃

Eq. wt. of Na₂CO₃.H₂O = \(\frac{\text{Mol. wt.}}2 = \frac{124}2= 62\)

62 g of sod. carbonate = 1 eq. sod. carbonate

0.62 g of sod. carbonate = \(\frac{1\times 0.62}{62}\) = 0.01 equi.

Calculation of equivalents of H₂SO₄ in 100 ml. of 0.1 N H₂SO₄

Equivalents of H₂SO₄ = \(\frac{0.1 \times 100}{1000}\) = 0.01 equi.

Since the two substances (Na₂CO₃ and H₂SO₄) are present in same equivalents they will completely neutralise each other and hence the resulting solution will be neutral.