Join TSR now and get all your revision questions answeredSign up now

Enthalpy question? Watch

    • Thread Starter
    Offline

    3
    ReputationRep:
    A large kettle operates at 1000 W and holds 5400 g of water when full. The temperature of tap water in spring is 10°C. Assume the water to be pure H2O with the following properties:

    molar mass = 18 g mol-1;
    CP = 4.2 J mol-1 K-1;
    ΔvapH = 41 kJ mol-1 (at 100°C).

    (i) How long would the kettle take to boil if filled with tap water? [6 marks]

    ΔT = (273+100) - (10 +273) = 90
    ΔH = q = CPΔT
    therefore, 4.2 J mol-1K-1 x 90K = 378 J mol-1 = q


    do we use this equation by anychance:
    S (final) = S(initial) + CP ln (T/Ti)


    Thank you!


    nevermind! I think I've got it!
 
 
 
Poll
Should gherkins be in burgers?

The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE

Quick reply
Reputation gems: You get these gems as you gain rep from other members for making good contributions and giving helpful advice.