An excess of sulfuric acid solution was added to a solution containing 20 g of sodium hydroxide. Calculate the mass of the salt obtained.

1) Find the molar mass of sodium hydroxide according to the periodic table: 23 + 16 + 1 = 40.
2) Find the amount of sodium hydroxide substance. To do this, divide its mass by the molar mass: 20/40 = 0.5 mol.
3) According to the reaction equation, there is one mole of sodium sulfate for two moles of sodium hydroxide. This means that the amount of sulfate substance is: 2 * 0.5 = 1 mol.
4) Molar mass of sodium sulfate: 23 * 2 + 39 + 4 * 16 = 149.
5) Mass of sodium sulfate: 1 * 149 = 149g – answer.