Question

When active metals such as magnesium are immersed in acid solution, hydrogen gas is evolved. (a)

Write the balanced equation (including physical states) for the reaction of magnesium metal with

hydrochloric acid (CH4 Activities series). (b) Calculate the volume of the H2(g) at 30.1°C and 0.85 atm

that can be formed when 275 mL of 0.725M HCl solution reacts with excess Mg according to the

balanced equation.

Answer 1

(a)Mg_(s) + 2HCl_(aq)-->MgCl_2(aq) + H_2(g) ;

(b) V₁(H₂)= (V(HCl)*C(HCl)*V_M)/2 = 0.275*0.725*22.4/2=2.23 L;

V₂(H₂)= V₁p₁T₂/p₂T₁ = 2.23*1*273/(0.85*303.1)=2.36 L;

Answer: 2.36 L