The reaction below is used to produce hydrogen gas 2 HCl aq

The reaction below is used to produce hydrogen gas

2 HCl (aq) + Zn (s) -------> ZnCl2 (aq) + H2 (g)

156 mL of H2 gas is collected at 19 oC. The total pressure of water vapor and hydrogen gas is 769 mm Hg. The partial pressure of the hydrogen gas is 752 mm Hg.

a. How many moles of H2 are collected? (Use PV=nRT, R = 0.0821(L atm/K mol)

b. If the temperature is raised to 60 oC and the volume kept constant, what will the total pressure be?

Solution

pv=nrt

(752/760)*0.156=n*0.0821*292

n=6.438*10-3

p1t2=p2t2

752*333=p2*292

p2=857.58 mm hg