please help me with this

Question

If 64.1 g of sulfur dioxide react completely with 159.9 g of bromine and an unknown amount of water to form 161.9 g of hydrogen bromide and 98.1 g of sulfuric acid, then how many grams of water react?

 

Answer 1

Using the law of conservation of matter, we know that the mass on the left side of the equation must equal the mass on the right side of the equation, assuming no losses and that the reaction is complete.

mass on left side = 64.1 g + 159.9 g + x g = 224 + x g

mass on right side = 161.9 g + 98.1 g = 260 g

224 + x g = 260 g

x = 36 g of water

Answer 2

Here is the reaction:

SO₂ + Br₂ + 2H₂O = 2HBr + H₂SO₄

64.1 grams of SO₂ is equal to 1 mol, so we have 1 mol of SO₂.

159.9 grams of Br₂ is how much 1 mol of bromine would weigh.

161.9 grams of HBr = mass of 2 mol

98.1 grams of H₂SO₄ = mass of 1 mol of H₂SO₄.

Then, from the equation of this reaction we can see that it requires 2 mols of H₂O (about 36 grams).