Question

Water in an electric Kettle is brought to boil in 180s by raising its temperature from 20°c to 100°c.It then takes a further 1200s to boil the kettle dry. Calculate the specific latent heat of vaporisation of water,L,at 100°c.The specific heat capacity of water is 4200J/kg/k.
State any assumptions made.​

Answer 1

Answer:

2-24×10^6J/kg

Explanation:

first calculate amount of heat required to raise temperature of water from 20 deree C 100 Degree C. divide this by time 180 to get power of kettle . assume there is 1 kg of water. using power of kettle calculate heat energy required to vapourise water by multiplying it by 1200. now calculate Lv by using formula

Lv = heat given / mass vapourised

see attachment