Calculate the mass of sodium hydroxide to react with 20g of 5% sulfuric acid solution.

1. Caustic soda neutralizes sulfuric acid, this process describes the equation:

2NaOH + H2SO4 = Na2SO4 + 2H2O;

2. Find the mass of the acid contained in the solution:

m (H2SO4) = w (H2SO4) * m (solution) = 0.05 * 20 = 1 g;

3. Calculate the chemical amount of sulfuric acid:

n (H2SO4) = m (H2SO4): M (H2SO4);

M (H2SO4) = 2 + 32 + 4 * 16 = 98 g / mol;

n (H2SO4) = 1: 98 = 0.0102 mol;

4. Using the ratio of the reactants, we will establish the amount of the reacted alkali:

n (NaOH) = n (H2SO4) * 2 = 0.0102 * 2 = 0.0204 mol;

5. Let’s calculate the mass of sodium hydroxide:

m (NaOH) = n (NaOH) * M (NaOH);

M (NaOH) = 23 + 17 = 40 g / mol;

m (NaOH) = 0.0204 * 40 = 0.816 g.

Answer: 0.816 g.