Question

Hydrogen gas can be prepared in the laboratory by a single-displacement reaction in which solid zinc reacts with hydrochloric acid.How much zinc in grams is required to make 14.4 g of hydrogen gas through this reaction?

Answer 1

Zn +2 HCl ---------> ZnCl2 + H2  

17.0 g H2 * 1 mol H2 / (2 * 1.008 g H2) * (1 mol Zn / 1 mol H2) =  

8.432 mol Zn required  

8.432 mol Zn * (65.39 g Zn / mol Zn) = 551.4 g Zn

Answer 2

Answer:

Explanation:

the balanced chemical equation for the displacement reaction between zinc and hydrchloric acid is given as

                   Zn + 2HCl → ZnCl₂ + H₂

mole ratio;    1   :   2             1      :   1

atomic mass of Zinc = 65.38g

atomic mass of hydrogen =1g

molecular mass of hydrgen(H₂) = 1×2=2g

from the chemical reaction above, it can be deduced that;

   2g of hydrgen gas is produced from 65.38g of solid zinc

∴   14.4g of hydrogen will be needing xg of solid zinc

x=$\frac{14.4 X 65.38}{2}$

x = 941.472 ÷ 2

x=470.7g

14.4g of hydrogen requires 470.7g of solid zinc