When 1224 J of heat energy is added to 39.6 g of ethanol, C 2 H 6 O, the temperature increases by 12.6 ∘ C. Calculate the molar heat capacity of C 2 H 6 O.

The molar heat capacity is 112.96 J/mol°C

Explanation:

Step 1: Data given

Amount of energy = 1224 J

Mass of ethanol = 39.6 grams

Temperature increases by 12.6 °C

Step 2:

Molar heat capacity is a measure of the amount of heat necessary to raise the temperature of one mole of a pure substance by one degree K.

Specific heat capacity is a measure of the amount of heat necessary to raise the temperature of one gram of a pure substance by one degree K.

Step 3: Calculate moles of ethanol

Moles ethanol = mass of ethanol / molar mass ethanol

Moles ethanol = 39.6g / 46.07 g/mol

Moles ethanol = 0.860 moles

Step 4: Calculate the specific heat capacity

q = m*c*ΔT

1224 = 39.6 * c * 12.6

the specific heat capacity of ethanol = 2.45 J/g°C

Step 5: Calculate the molar heat capacity

q = n * c * ΔT

1224 J = 0.860 moles * c * 12.6 °C

c = 112.96 J/mol°C

This can be controlled by: specific heat capacity * molar mass

2.45 J / g°C * 46.07 g/mol = 112.9 J / mol °C

The molar heat capacity is 112.96 J/mol°C