Question

A chemical reaction transfers 6650 J of thermal energy into 11.4 moles of an ideal gas while the system expands by 2.00 ✕ 10^−2 m^3 at a constant pressure of 1.33 ✕ 10^5 Pa.

(a) Find the change in the internal energy (in J). ___________J

(b) Calculate the change in temperature of the gas (in K). _______________K

Answer 1

Given

Heat transfer =6650 J

Number of moles n=11.4

Change in volume =+ 2.00 10^-2 m³ (+ sign represent expansion)

Pressure P=1.3310⁵ Pa

a) Change in internal energy is given by First Law of Thermodynamics

where is work done

=1.3310⁵ Pa 2.00 10^-2 m³ =2.66 10³ =2660 J

So = 6650 -2660 = 3990 J

b) For isobaric process (constant pressure) the work done is given by

where n is number of moles R is gas constant R=8.314 J K^-1mol^-1

we have =2660 J calculated in part a

so =2660

so  

so

Change in temprature 28.065 K