Question

predict the mass of hydrogen gas produced when 2.73g of aluminum reacts in a single replacement reaction with excess sulphuric acid.
2Al+ 3H2SO4--> 3H2+Al2(SO4)3

Answer 1

For answering this question you need the next:
Molecular weight of Al = 26.98
Molecular weight of H2 = 2.01

& 2.73g m
2Al & + 3H2SO4--> 3H 2+Al2(SO4)3
2*26.98 & 3*2.01


m= 2.73 * 3*2.01/ (2*26.98& ) = 0,0363 g