To calculate the internal energy and enthalpy of heating of 100 g of Na(s) from 60°C to 85°C, we need to use the following equations:
ΔU = nCvΔT
ΔH = nCpΔT
where ΔU is the change in internal energy, ΔH is the change in enthalpy, n is the number of moles of Na(s), Cv is the specific molar heat capacity at constant volume, Cp is the specific molar heat capacity at constant pressure, and ΔT is the change in temperature.
First, we need to calculate the number of moles of Na(s):
n = m / M
where m is the mass of Na(s) and M is the molar mass of Na. The molar mass of Na is 22.99 g/mol:
n = 100 g / 22.99 g/mol = 4.35 mol
Next, we can calculate the change in internal energy:
ΔU = nCvΔT = 4.35 mol x 31.51 J/(mol K) x (85°C - 60°C) = 3,135 J
Finally, we can calculate the change in enthalpy:
ΔH = nCpΔT = 4.35 mol x 28.20 J/(mol K) x (85°C - 60°C) = 2,738 J
Therefore, the internal energy of heating of 100 g of Na(s) from 60°C to 85°C is 3,135 J and the enthalpy of heating is 2,738 J.