Final answer:
To melt 8.65 moles of isopropyl alcohol, 11.1 kilocalories of heat are required. This is calculated by converting moles to grams, multiplying by the heat of fusion, and converting calories to kilocalories.
Step-by-step explanation:
To calculate the amount of heat in kilocalories required to melt 8.65 moles of isopropyl alcohol, we first need to find the total heat in calories needed by using the heat of fusion value and then convert the total heat to kilocalories. The heat of fusion of isopropyl alcohol is 21.4 cal/g. To begin, we convert moles to grams using the molar mass of isopropyl alcohol which is 60.0 g/mol.
8.65 moles of isopropyl alcohol × 60.0 g/mol = 519 g of isopropyl alcohol
Next, we multiply the mass of isopropyl alcohol by its heat of fusion:
519 g × 21.4 cal/g = 11106.6 calories
Now, to convert calories to kilocalories, we divide by 1000, as there are 1000 calories in a kilocalorie:
11106.6 calories ÷ 1000 = 11.1 kilocalories
Therefore, 11.1 kilocalories of heat are required to melt 8.65 moles of isopropyl alcohol.