What is the mass of 40% sodium hydroxide, you need to take for the reaction with 35.1 liters of sulfur oxide.

1. Let’s write the equation of the chemical reaction:

2NaOH + SO2 = Na2SO3 + H2O.

2. Find the chemical amount of sulfur dioxide (Vm – molar volume, constant equal to 22.4 l / mol):

n (SO2) = V (SO2) / Vm = 35.1 L / 22.4 L / mol = 1.57 mol.

3. Using the reaction equation, we find the chemical amount, and then the mass of sodium hydroxide:

n (NaOH) = n (SO2) * 2 = 1.57 mol * 2 = 3.13 mol.

m (NaOH) = n (NaOH) * M (NaOH) = 3.13 mol * 40 g / mol = 125.4 g.

4. Find the mass of the sodium hydroxide solution:

m (solution) = m (NaOH) * 100% / ω (NaOH) = 125.4 g * 100% / 40% = 313.4 g.

Answer: m (solution) = 313.4 g.