JAMB - Chemistry (1987 - No. 21)
A stream of air was successively passed through three tubes X, Y and Z containing a concentrated aqueous solution of KOH, red hot copper powder and fused calcium chloride respectively. What was the composition of the gas emanating from tube Z?
CO2 ad ithe inert gases
N2, CO2 and the inert gases
N2 and the inert gases
water vapour, N2 and the inert gases
Објашњење
When a stream of air is passed through a tube containing fused Calcium chloride, the calcium chloride absorbs moisture (water vapour) from the air because it is deliquiscent. Thus, the gas emanating from the tube will be dry air(Nitrogen and inert gas) with a significant reduced or negligible amount of water vapour.