Question

How mans, gram of HBr would exactly be

required to react with 2g of propyne ?
(Br=80,H=1, c=12) C3 H4+2HBr–> C3 H6 Br2

Answer 1

The number of moles of HBr required to react with 2 g of propyne can be calculated by using the balanced chemical equation:

C3 H4 + 2HBr → C3 H6 Br2

The molar mass of propyne is (3 x 12 + 4 x 1) = 40 g/mol

So, 2 g of propyne is equal to 2/40 = 0.05 moles of propyne.

Since 2 moles of HBr are required to react with 1 mole of propyne, then 0.05 moles of propyne would require 0.05 x 2 = 0.1 moles of HBr.

Finally, to find the number of grams of HBr, we multiply the number of moles by its molar mass, which is (1 x 1 + 80 x 1) = 81 g/mol

So, 0.1 moles of HBr is equal to 0.1 x 81 = 8.1 g of HBr.