Final answer:
To melt 2.6 moles of isopropyl alcohol, we calculate the mass (2.6 mol x 60.0 g/mol) and then multiply by the heat of fusion (21.4 cal/g) to find the heat required in calories (3339.6 cal) and then convert to kilocalories, resulting in 3.34 kilocalories.
Step-by-step explanation:
The question asks how much heat is required to melt 2.6 moles of isopropyl alcohol, given that its heat of fusion is 21.4 cal/g. To answer this, we'll start by calculating the total mass of isopropyl alcohol and then use the heat of fusion to determine the total amount of heat in calories. Lastly, we'll convert the heat from calories to kilocalories.
First, we find the total mass of isopropyl alcohol by multiplying the molar mass by the number of moles:
Total mass = 2.6 mol x 60.0 g/mol = 156.0 grams
Next, we calculate the heat needed to melt this mass using the heat of fusion:
Heat required (in calories) = Total mass x Heat of fusion = 156.0 g x 21.4 cal/g = 3339.6 calories
To convert the heat into kilocalories, we divide by 1000:
Heat required (in kilocalories) = 3339.6 calories / 1000 = 3.34 kilocalories