Question

All alkali metals react with water to produce hydrogen gas and the corresponding alkali
metal bydroxide. A typical reaction is that between lithium and water:
2Li(s) + 2H20(1) - +2LiOH(aq) + H2(g)
How many grams of Li are needed to produce 9.89 g of H2?

Answer 1

Resposta: 69,23 is the mass of Li necessary to produce 9,89 g of H2 .

Explicação:

The equation is adjusted.

Considering weight mass of Li = 7 u and H = 1 u, we write:

2 Li ============ H2

2x7                         2x1

w                             9,89 g

w = 2x7x9,89//2 = 69,23 g