Question

An experimenter adds 979 J of heat to an ideal gas to heat it from 10.6 C to 26.4 C at constant pressure. The gas does +221 J of work during the expansion. Calculate the number of mol of gas. Give an answer with 3 significant figures.

Answer 1

n = 0.594 mol

Step-by-step explanation:

Parameters of the question.

Heat = 979J

Initial Temperature (T1) = 10.6 C = 283.6 K (converting to Kelvin by adding 273)

FinalTemperature (T2) = 26.4 C = 299.4 K (converting to Kelvin by adding 273)

ΔT = T2 -T1 = 299.4 - 283.6 = 15.8K

Work done (W) = 221 J

number of moles (n) = ?

Formular to be used;

W=PΔV

From ideal gas equation,

PV = nRT

PΔV = nRΔT

where R = gas constant = 8.314 J / mol·K

Sunstituting in the work done equation,

we have W=nRΔT

Making n subject of formular,

`n = (RT)/(W)`

n = [8.314 * 15.8]/221

n = 131.36/221

n = 0.594 mol