Question

how many moles of propane gas are in a 7.0 l tank at 20°c and 5.45 atm of pressure? 1.59 mol 25.2 mol 917 mol 0.629 mol

Explanation:

Step1: Convert temperature to Kelvin

$$T = 20 + 273.15 = 293.15\ K$$

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

We know \(P = 5.45\ atm\), \(V = 7.0\ L\), \(R=0.0821\ L\cdot atm/(mol\cdot K)\)
Rearrange for \(n\): \(n=\frac{PV}{RT}\)
Substitute values: \(n=\frac{5.45\times7.0}{0.0821\times293.15}\)
Calculate numerator: \(5.45\times7.0 = 38.15\)
Calculate denominator: \(0.0821\times293.15\approx24.07\)
Then \(n=\frac{38.15}{24.07}\approx1.59\ mol\)

Answer:

\(1.59\ mol\)