- #1

HelloCthulhu

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## Homework Statement

2 moles of water at 20°C undergoes electrolysis at 5A/40V inside of a closed 40mL container for 1 min at standard external/internal pressure. What is the final volume of the system?

## Homework Equations

(Q*M)/(F*z)=m

Q=c x m x ΔT

Vi/Ti = Vf/Tf

## The Attempt at a Solution

Gas Produced

(5A*60s*4g)/(F*4)=0.00311g H2

(5A*60s*32g)/(F*4)=0.024875g O2

0.00311g + 0.024875g = 0.02798g

Temperature of the system

Q=cmΔT

5A*40V*60s=12kJ

Liquid 36g x 4.18J/(g⋅K)=150.48J/(g⋅K)

Gas 0.02798g x 2.080J/(g⋅K)=0.0582J/(g⋅K)

150.48J/(g⋅K) + 0.0582J/(g⋅K)=150.538J/(g⋅K)

12kJ=150.538J/(g⋅K)/(g⋅K)*ΔT

12kJ/150.538J/(g⋅K)=(T2-20°C)

79.7 + 20°C=99.7°C

Does the rise in temperature cause the total volume of the system to increase? If so, how do I calculate the change in volume? I think I'm supposed to use the volume of the container as initial volume and use Charle's law to calculate the change but I'm not sure in this case.

Vi/Ti = Vf/Tf

0.040L/293K=Vf/372.85

Vf=0.05L