Question

) A 1.0kW kettle contains 500g of boiling waterCalculate the time needed to evaporate all the water

Answer 1

Answer:

t = 1130 s = 18.83 min

Explanation:

First, we will calculate the energy required to evaporate 500 g of water:

$E = mL$

where,

E = Energy Required for evaporation of water =?

m = mass of water = 500 g = 0.5 kg

L = Latent heat of vaporization of water = 2.26 MJ/kg = 2260 KJ/kg

Therefore,

$E = (0.5\ kg)(2260\ KJ/kg)\\E = 1130\ KJ$

Now, we will calculate the time required:

$P = \frac{W}{t}\\\\t = \frac{W}{P}$

where,

t = time = ?

P = Power of kettle = 1 KW

Therefore,

$t = \frac{1130\ KJ}{1 KW}$

t = 1130 s = 18.83 min