Question

1. how many calories of heat are needed to melt 75g of ice at 0°c?

Explanation:

Step1: Recall the latent heat of fusion for ice

The latent heat of fusion for ice (the heat required to melt 1 gram of ice at \(0^\circ\text{C}\) into water at \(0^\circ\text{C}\)) is \(80\) calories per gram (\(80\,\text{cal/g}\)).

Step2: Calculate the heat required

To find the total heat (\(Q\)) needed to melt a mass (\(m\)) of ice, we use the formula \(Q = m\times L_f\), where \(L_f\) is the latent heat of fusion. Here, \(m = 75\,\text{g}\) and \(L_f=80\,\text{cal/g}\).

So, \(Q = 75\,\text{g}\times80\,\text{cal/g}\)

Step3: Perform the multiplication

\(75\times80 = 6000\)

Answer:

6000 calories