Question

50g of water were heated to boiling point at constant rate of 2.28KJ per munite. After boiling for 10 minutes, the mass of water decreased to 40g. Calculate the heat of vaporization of water.

Answer 1

please clarify what to find? specific latent heat of vapourisation or the temp of vapour

Answer 2

Answer:

using the formula Q=mHv, where Q is the quantity of heat in joules or kilo joules, m is mass in grams and Hv is the heat of vaporization in J/g.

The heat flow per min is 2.28kj/min, therefore, in 10 mins the total heat will be 2.28kj/min x 10mins= 22.8kj

so Q=22.8kj

recall, that 50g became 40g. That means 10g of water was vaporise by the 22.8kj of heat.

so; HV = Q/m

HV = 22.8kj÷ 10g

HV = 2.28kj/g

HV = 2280j/g