Question

A chemist carefully measures the amount of heat needed to raise the temperature of a 0.47 kg sample of C6H7N from 30.5 degrees C to 48.4 degrees C. The experiment shows that 1.65 x 10^4 J of heat are needed. What can the chemist report for the molar heat capacity of C6H7N? Be sure your answer has the correct number of significant digits.

Answer 1

The molar heat capacity of C6H7N is 6.79 J/(mol·°C)

Step-by-step explanation:

The molar heat capacity (Cp) of a substance is the amount of energy needed to increase the temperature of 1 mol of the substance by 1°C. In this case, the chemist wants to find the molar heat capacity of C6H7N. To do this, we can use the equation:

q = m × Cp × ΔT

Where q is the heat transferred, m is the mass of the substance, Cp is the molar heat capacity, and ΔT is the change in temperature.

From the question, we know that the mass of the sample is 0.47 kg, the heat transferred is 1.65 x 10^4 J, and the change in temperature is 48.4°C - 30.5°C = 17.9°C

Plugging these values into the equation:

1.65 x 10^4 J = 0.47 kg × Cp × 17.9°C

Solving for Cp:

Cp = (1.65 x 10^4 J) / (0.47 kg × 17.9°C) = 6.79 J/(mol·°C)

Therefore, the chemist can report the molar heat capacity of C6H7N as 6.79 J/(mol·°C).

Answer 2

`\bull\sf m=0.47kg`

`\bull\sf \Delta T=T_f-T_i=48.4-30.5=17.9°C`

`\bull\sf Q=1.65* 10^4J`

We know according to thermodynamics

`\\ \sf\longmapsto Q=mc\Delta T`

`\\ \sf\longmapsto c=(Q)/(m\Delta T)`

`\\ \sf\longmapsto c=(1.65* 10^4)/(0.47* 17.9)`

`\\ \sf\longmapsto c=(1.65* 10^4)/(8.413)`

`\\ \sf\longmapsto c=0.1961* 10^4J/kg°C`

`\\ \sf\longmapsto c=1961J/kg°C`