Question

Какому веществу парафину или свинцу потребуется большее количество теплоты, если надо расплавить 5 кг парафина и 30 кг свинца, находящихся каждый при своей температуре плавления?

Answer 1

Свинцу больше потребуется потому что его больше

Answer 2

Comparing Heat Required to Melt Paraffin and Lead

To determine which substance, paraffin or lead, requires more heat to melt, we can use the formula:

Q = m * L

Where: - Q is the heat required, - m is the mass of the substance, and - L is the specific latent heat of fusion.

Specific Latent Heat of Fusion

The specific latent heat of fusion for paraffin is 200 kJ/kg, and for lead is 24.5 kJ/kg.

Calculating the Heat Required

For paraffin: - Mass (m) = 5 kg - Specific latent heat of fusion (L) = 200 kJ/kg

For lead: - Mass (m) = 30 kg - Specific latent heat of fusion (L) = 24.5 kJ/kg

Using the formula Q = m * L, we can calculate the heat required for each substance.

For paraffin: Q_paraffin = 5 kg * 200 kJ/kg = 1000 kJ.

For lead: Q_lead = 30 kg * 24.5 kJ/kg = 735 kJ.

Conclusion

Therefore, it will require a greater amount of heat to melt 30 kg of lead compared to 5 kg of paraffin.