Calculate the heat in kJ required to convert 2.1 g of water at 52.1°C to steam at 100°C. The specific heat of water is 4.184 J/g°C and the heat of vaporization of water is 2260 J/g.

5.167 kJ

Explanation:

We have to divide the heating process into two steps: one for the heating process of liquid water (1) and the other for the phase transition from liquid water to steam at 100°C (2)

1 - heating from 52.1°C to 100°C:

heat(1) = m x Cp x ΔT = 2.1 g x 4.184 J/g°C x (100°C-52.1°C) = 420.9 J

2 - vaporization at 100°C:

heat(2) = m x ΔHv = 2.1 g x 2260 J/g = 4746 J

Finally, we add the heat values of the steps:

heat required = heat(1) + heat(2) = 420.9 J + 4746 J = 5166.9 J

Since 1 kJ= 1000 J, we convert from J to kJ:

5166.9 J x 1 kJ/1000 J = 5.1669 kJ ≅ 5.167 kJ

plants need sunlight, water, and carbon dioxide to make food. plants use the raw materials of water, nutrients they absorb from soil, and carbon dioxide to make sugars the plant can use. energy from the sun and chlorophyll are also needed.