Question

A reaction taking place in a container with a piston-cylinder assembly absorbs 4850. J of heat and has a change in the internal energy of 1618.5 j. What is the final volume of the container if the reaction occurs under a constant external pressure of 5.5 atm and the initial volume of the container is 10.5 l?

Answer 1

`V_f = 16.3 Ltr`

Step-by-step explanation:

As per first law of thermodynamics we know that

heat absorbed = change in internal energy + Work done

so we have

`Heat = 4850 J`

`\Delta U = 1618.5 J`

so work done is given as

`4850 = 1618.5 + W`

`W = 3231.5 J`

now we know that at constant pressure the work done is given as

`W = P\Delta V`

`3231.5 = P(V_f - V_i)`

`3231.5 = 5.5 * 1.01 * 10^5(V_f - 10.5 * 10^(-3))`

`V_f = 16.3 * 10^(-3) m^3`

or we have

`V_f = 16.3 Ltr`