Question

When the NaOH dissolves, the temperature of the solution increases from 18.2 C to 24.5 C. Assuming the specific heat and density of the solution is approximately that of water, what is the heat of solution of NaOH in kJ/mol?

Answer 1

Answer:

The heat of solution is 1.05 kJ/mol

Explanation:

NaOH → Molar mass 40 g/m

This is the mass in 1 mol

Calorimetry formula:

Q = m . c . ΔT

ΔT = T° final - T° initial = 24.5°C - 18.2°C = 6.3°C

mass = 40 g

c = 4.186 kJ/kg°C (the same as water)

So we have to convert 40 g to kg

40 g/1000 = 0.04 kg

Q = 0.04 kg . 4.186 kJ/kg°C . 6.3 °C = 1.05 kJ