Question

quiz - gas laws
name: ebteisam
questions

1. a canister filled with 2.25g of argon gas has a fixed volume of 455ml. if this canister is kept at a temperature of 32°c, the pressure inside of the canister will be ____ kpa.

your answer

Explanation:

Step1: Convert units

First, convert mass of argon to moles. Molar - mass of argon ($Ar$) is $M = 39.95g/mol$. Number of moles $n=\frac{m}{M}$, where $m = 2.25g$. So $n=\frac{2.25g}{39.95g/mol}\approx0.0563mol$. Also, convert temperature to Kelvin: $T=(32 + 273)K=305K$ and volume to liters: $V = 455mL=0.455L$.

Step2: Apply ideal - gas law

The ideal - gas law is $PV=nRT$, where $R = 8.314J/(mol\cdot K)$. We want to find pressure $P$, so $P=\frac{nRT}{V}$.
Substitute the values: $P=\frac{0.0563mol\times8.314J/(mol\cdot K)\times305K}{0.455L}$.
$P=\frac{0.0563\times8.314\times305}{0.455}kPa$ (since $1J = 1Pa\cdot m^{3}$ and $1L = 1dm^{3}=0.001m^{3}$, the units work out to kPa).
$P=\frac{0.0563\times8.314\times305}{0.455}\approx311kPa$.

Answer:

311