JAMB - Chemistry (2005 - No. 19)

25cm\(^3\) of a mixture of noble gases was obtained from air after the removal of other constituents. What was the original volume of air?

2,500 cm³

1250 cm³

125 cm³

80 cm³

Noble gases, primarily argon, make up about 1% of Earth's atmosphere, with argon being the most abundant at 0.934%.

Volume of noble gases in air mixture = % composition of noble gas X Total volume of air mixture

25cm\(^3\) = 1% X V\(_T\)

25cm\(^3\) = \(\frac{1}{100}\times {V_T}\)

25cm\(^3\) = \(\frac{V_T}{100}\)

V\(_T\) = 25 X 100

∴ V\(_T\) = 2,500cm\(^3\)