A 150 W heater was placed in 1 kg of methanol and turned on exactly fo...
Calculation of Molar Heat Capacity of Methanol
Formula Used
The formula used to calculate the molar heat capacity is:
Cp = Q/mΔT
Where,
Cp = molar heat capacity of the substance
Q = heat energy supplied
m = mass of the substance
ΔT = change in temperature
Calculation
Given,
Power of the heater (P) = 150 W
Time for which heater was turned on (t) = 1 min = 60 s
Change in temperature (ΔT) = 3.54 K
Mass of methanol (m) = 1 kg
Molar mass of methanol (M) = 32 g/mol
We know that,
Power (P) = energy/time
So, energy (Q) supplied by the heater in 1 minute can be calculated as:
Q = P × t
= 150 W × 60 s
= 9000 J
Using the formula mentioned above, we can calculate the molar heat capacity as:
Cp = Q/mΔT
= (9000 J) / (1 kg × 3.54 K)
= 2540.11 J/mol K
Answer
Therefore, the molar heat capacity of methanol is 2540.11 J/mol K.