Calculate the mass of the formed silicic acid as a result of the interaction of sodium silicate

Calculate the mass of the formed silicic acid as a result of the interaction of sodium silicate with 100 g. 20% hydrochloric acid solution.

Given:

m (solution HCl) = 100 g

w% (HCl) = 20%

Find:

m (H2SiO3) -?

Solution:

2HCl + Na2SiO3 = 2NaCl + H2SiO3, – we solve the problem, relying on the composed reaction equation:

1) Find the mass of hydrochloric acid in the reacted solution:

m (HCl) = 100 g * 0.2 = 20 g

2) Find the amount of hydrochloric acid:

n (HCl) = m: M = 20 g: 36.5 g / mol = 0.55 mol

3) We compose a logical expression:

If 2 mol of HCl gives 1 mol of H2SiO3,

then 0.55 mol HCl will give x mol H2SiO3,

then x = 0.275 mol.

4) Find the mass of silicic acid precipitated during the reaction:

m (H2SiO3) = n * M = 0.275 mol * 78 g / mol = 21.45 g.

Answer: m (H2SiO3) = 21.45 g.