Question

1. a gas evolved during the fermentation of sugar was collected at 295.5 k and 702 mm hg. 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. 23.6 mol

Explanation:

Step1: Convert pressure to atm

We know that \(1\space atm = 760\space mm\space Hg\).
So, \(P=\frac{702}{760}\space atm\approx0.924\space atm\)

Step2: Use ideal gas law \(PV = nRT\)

The ideal gas law is \(n=\frac{PV}{RT}\), where \(R = 0.0821\space L\cdot atm/(mol\cdot K)\), \(V = 25.0\space L\), \(T=295.5\space K\), and \(P = 0.924\space atm\)
Substitute the values: \(n=\frac{0.924\times25.0}{0.0821\times295.5}\)
First calculate the numerator: \(0.924\times25.0 = 23.1\)
Then calculate the denominator: \(0.0821\times295.5\approx24.26\)
Now, \(n=\frac{23.1}{24.26}\approx0.95\space mol\)

Answer:

A. \(0.95\space mol\)