"Mg(s) + 2HCl(aq)=MgCl2(aq) +H2(g)

Question

so theres like 2 parts to this question,   a. How many grams of HCl are consumed by the reaction of 5.13 moles of magnesium? b. Whatis the mass in grams of H2 gas when 1.62 moles of Hcl is added to the reaction?

Answer 1

Mg(s) + 2HCl(aq) ===> MgCl2(aq) + H2(g)

a)  2 moles HCl/1 moles Mg x 5.13 moles Mg = 10.26 moles HCl x 36.5 g/mole HCl = 375 g HCl (3 sig. figs.)

 

b)  1 moles H2(g)/2 moles HCl x 1.62 moles HCl = 0.81 moles H2 gas x 2 g/mole = 1.62 g H2(g) (3 sig. figs)