Question

A gas evolved during the fermentation of sugar was collected at 22.5°C and 702 mmHg. After purification its volume was found to be 25.0 L. How many moles of gas were collected?
A) 0.95 mol
B) 1.05 mol
C) 12.5 mol
D) 22.4 mol
E) 724 mol

Answer 1

Answer:

A) 0.95 mol

Explanation:

We will assume the gas given off in the fermentation is an ideal gas because that allows us to use the ideal gas equation.

PV  = nRT

First let's convert all measurements to units that we can use

P = 702 mmHg * 1 atm/760 mmHg = 0.92368 atm

V = 25.0 L

R = 0.08206 L-atm/mol-K

T = 22.5 °C +273.15 = 295.65 K

PV  = nRT

0.92368 atm * 25.0 L = n * 0.08206 L-atm/mol-K * 295.65 K

                                  n = 0.9518 mol