Answer to Question #186523 in General Chemistry for Jay an C. Agustin

Question

What is the mass of hydrogen gas produced from the reaction of 5.0g of lithium metal in excess water? ( Li:6.9g/mol, H:1.0g/mol, O:16.0g/mol

Answer 1

2Li + H2O ----> Li2O + H2

From the balanced equation above

2(6.9)g of Li produced 2.0g of H2

5.0g of Li will produce 2.0/13.8 x 5.0 = 0.72g of H2