Calculate the heat energy required to vapourize 50g of water initially at 80^oC if the specific heat capacity of water is 4.2Jg^-1K (specific latent heat of vapourization of water is 2260Jg^-1).

Mrnoah

1 year ago

To calculate the heat energy required, we need to consider two steps:

1. Heating the water from 80°C to 100°C (boiling point).
2. Vaporizing the water at 100°C.

Step 1: Heating the water from 80°C to 100°C:

Q1 = mcΔT

where:

m = 50 g
c = 4.2 J/gK
ΔT = 100°C - 80°C = 20 K

Q1 = 50 g × 4.2 J/gK × 20 K = 4200 J

Step 2: Vaporizing the water at 100°C:

Q2 = mL

where:

m = 50 g
L = 2260 J/g

Q2 = 50 g × 2260 J/g = 113000 J

Total heat energy required:

Q = Q1 + Q2 = 4200 J + 113000 J = 117200 J

Therefore, the heat energy required to vaporize 50g of water initially at 80°C is approximately 117200 J or 117.2 kJ.

NursePro

3 months ago

where is the 100 -80 from