Question

If the heat of fusion for water is 80. cal/g, how many calories are needed to melt 45.0 g of ice at 0 °C?

1) 3.6 cal
2) 3.6 x 10³ cal
3) 1.8 cal
4) 80. cal
5) 0.56 cal

Answer 1

To melt 45.0 g of ice at 0 °C, the total amount of heat needed is calculated by multiplying the mass of the ice by the heat of fusion, resulting in 3600 calories, which corresponds to option 2) 3.6 x 10³ cal.

Step-by-step explanation:

The question asks how many calories are needed to melt 45.0 g of ice at 0 °C given the heat of fusion for water is 80. cal/g. To find the total amount of heat (Q) required, we use the formula:

Q = mass of ice (g) × heat of fusion (cal/g)

So, for 45.0 g of ice:

Q = 45.0 g × 80. cal/g = 3600 cal

This result shows that it takes 3600 calories to melt 45 g of ice at 0 °C. Therefore, the correct answer is 2) 3.6 x 10³ cal.