Question

Given: __ BaBr2 + ___Na2SO4 --> a) Determine the balanced equation b) How many grams of barium bromide are needed to react with 0.625 grams of sodium sulfate ?

Answer 1

a) The correct balancing of this reaction is:

BaBr2 + Na2SO4 -> BaSO4 + 2NaBr

Which is letter C

b) 0.625 grams of Na2SO4, we need to find the number of moles of Na2SO4 in the reaction, to do that we will need the molar mass, which is 142.04g/mol, therefore

142.04 g = 1 mol

0.625 g = x moles

x = 0.0044 moles of Na2SO4 in the reaction

In order to react, we need 1 Na2SO4 and 1 BaBr2, we know that by checking our balanced equation, so if we have a 1:1 ratio in the equation, if we have 0.0044 moles of Na2SO4, we will also need 0.0044 moles of BaBr2

Now to find the mass of BaBr2, we will also use its molar mass, which is 297.14g/mol

297.14 g = 1 mol

x grams = 0.0044 moles

x = 1.31 grams of BaBr2

Option D