Question

Hydrobromic acid dissolves solid iron according to the followiaung reaction:

Fe(s)+2HBr(aq)→ FeBr2(aq)+ H2(g)

Part A. What mass of HBr (in g) would you need to dissolve a 3.6-g pure iron bar on a padlock?

Part B. What mass of H2 would be produced by the complete reaction of the iron bar?

Answer 1

Let x be the mass of HBr required to dissolve 3.6 g of Fe

2*80.91 g of HBr requires--------> 56 g of Fe

X g of HBr requires-----------------> 3.6 g of Fe

Cross multiply

2*80.91*3.6= 56 x

X=10.4027142857 g of HBr

Let x be the mass of hydrogen produced by 3.6 g of Fe

56 g of Fe gives-----> 2 g of H2

3.6 g of Fe gives-----> x g of H2

Cross multiply

56*x=3.6*2

X=0.12857142857 g of Hydrogen