Question

Ammonia, NH3(g), and hydrogen chloride, HCl(g), react to form solid ammonium chloride, :
NH3(g) + HCl(g) ----> NH4Cl
Two 2.00 flasks at 30.0 are connected by a stopcock, as shown in the drawing. One flask contains 5.20g NH3(g), and the other contains 4.40g HCl(g). When the stopcockis opened, the gases react until one is completely consumed. What will be the final pressure of the system after the reaction is complete? (Neglect the volume of theammonium chloride formed.)

Answer 1

answer: 1.04 atm

first, convert g to moles for both
5.20 g NH3 x 1 mole/17 g = .306 moles
4.40 g Cl x 1mole/36.5 = .121 moles

Cl is the limiting reagent. with 1:1 so assume all but .185 mole of the NH3 reacts. that will be n.

The volume of the system is 4L. PV=nRT with r = .0821 L*atm/(K*mol)
Ignore the volume of the solid. assume 273 kelvin.