How much energy is required to melt 1.5 kg of lead?

Answer 1

36.8 kj

Answer 2

(Explanation): use latent heat of fusion value to solve. we will be using Q=(m)(Hfus) to solve this. Q=(1.5)(24.5) = 36.75, or 36.8. We don't need to convert kg to grams for this one because the units of Hfus are already in kg.

Answer 3

Strictly speaking, lead won't melt at 10 °C. You could do a theoretical calculation however by calculating the enthalpy change to take solid lead at 10 °C up its melting point at 327.5 °C, add the enthalpy of melting, and then subtract the enthalpy to cool liquid lead back to 10 °C. This last measurement would be only theoretical since lead will not remain liquid as you cool it below its melting point.

Enthalpy of melting = 22.4 kJ/kg

Specific heat of solid lead is ~130 J/kg/°C (its actually a function of temperature, but this average should suffice)

Specific heat of liquid lead is ~152 J/kg/°C (note that this is only theoretical below the melting point of lead.

Using these values, the theoretical energy required to melt 1 kg of lead at 10 °C would be:

130(327.5-10)J + 22400 J + 152(10-327.5)J = 15415 j = 15.415 kJ

Answer 4

36.8kJ

Answer 5

1935