Question

When 2. 0 mol CO2 is heated at a constant pressure of 1. 25 atm, its temperature increases from 250 K to 277 K. Given that the molar heat capacity of CO2 at constant pressure is 37. 11 JK-1mol-1 , calculate q, ∆ H and ∆ U

Answer 1

Answer: See below

Step-by-step explanation:

`\mathrm{At \ constant \ pressure \ the \ heat \ generated \ and \ change \ in \ enthalpy \ are \ equal:} \\\begin{aligned}Q &=\Delta H=n C_(p) \Delta T \\&=2 *(37.11)(277-250) \\&=2003.94 \mathrm{~J} \\Q &=\Delta H=2.0 * 10^(3) \mathrm{~J}\end{aligned}`

`\mathrm{Calculate \ the \ change \ in \ internal \ energy:} \\$$\begin{aligned}\Delta H &=\Delta U+\Delta(P V) \\\Delta U &=\Delta H-n R \Delta T \\&=(2003.94)-(2 * 8.314 *(277-250)) \\&=(2003.94)-(448.96) \\\Delta U &=1554.98 \mathrm{~J}\end{aligned}`