Chemistry Labs

Problem 1

A mixture of hydrogen and chlorine kept in a closed flask at constant temperature was irradiated by scattered light. After a certain time the chlorine content had decreased by 20 % compared with that of the starting mixture, and the resulting mixture had the composition: 60 volume % chlorine, 10 volume % hydrogen and 30 volume % hydrogen chloride. (a) What was the composition of the initial gaseous mixture? (b) How are chlorine, hydrogen and hydrogen chloride produced industrially?
Step 2 of 3: Initial composition
φ0(ClX2)=60+15=75 %,φ0(HX2)=10+15=25 %\varphi_0(\ce{Cl2}) = 60 + 15 = 75\ \%, \quad \varphi_0(\ce{H2}) = 10 + 15 = 25\ \%
Analysis

Adding the consumed volumes back to the measured final composition gives 75 % Cl2 and 25 % H2. Check: Cl2 fell from 75 to 60, i.e. exactly by 20 % as stated.