An excess of dilute sulfuric acid was added to a mixture of 34.8 pyrolusite and 41.2 g

An excess of dilute sulfuric acid was added to a mixture of 34.8 pyrolusite and 41.2 g of sodium bromide, and bromine was collected in 80% yield. How much 1-butylene can react with the bromine produced?

2NaBr + MnO2 + 2H2SO4 = Br2 + MnSO4 + Na2SO4 + 2H2O
n (MnO2) = 34.8 / 87 = 0.4 mol
n (NaBr) = 41.2 / 103 = 0.4 mol
This means that manganese oxide is in excess, since sodium bromide according to the reaction equation requires twice as much. We count by lack
n teor (br2) = 1 / 2n (NaBr) = 0.2 mol
n prak (Br2) = 0.2 * 0.8 = 1.6 mol
The interaction of bromine with butylene proceeds in a 1: 1 ratio, therefore the amount of butylene substance is equal to the amount of bromine substance = 1.6 mol
V (C4H8) = 1.6 * 22.4 = 3.584 l