Question

what is the change in heat when 50.0 g of isopropyl alcohol (c3h8o) melts, given that δhfus of isopropyl alcohol = 5.37 kj/mol?

Answer 1

The change in heat when 50.0 g of isopropyl alcohol (
`C_3H_8O`) melts is approximately 4.46 kJ

To find the change in heat when isopropyl alcohol (
`C_3H_8O`) melts, you can use the formula:

Change in heat = moles of substance × ΔHfus

First, let's find the number of moles of isopropyl alcohol:

Molar mass of isopropyl alcohol (
`C_3H_8O`) = 3 × (atomic mass of C) + 8 × (atomic mass of H) + 1 × (atomic mass of O)

= 3 × (12.01 g/mol) + 8 × (1.01 g/mol) + 1 × (16.00 g/mol)

= 36.03 g/mol + 8.08 g/mol + 16.00 g/mol

= 60.11 g/mol

Now, calculate the moles of isopropyl alcohol:

moles = mass / molar mass = 50.0 g / 60.11 g/mol

moles ≈ 0.831 mol

Now, use the formula to find the change in heat:

Change in heat = moles × ΔHfus

Change in heat = 0.831 mol × 5.37 kJ/mol

Change in heat ≈ 4.46 kJ

Therefore, the change in heat when 50.0 g of isopropyl alcohol melts is approximately 4.46 kJ.