Post Utme Chemistry Past Questions and Answers

Question 816:

In the reaption \(SnO _{2}+2 C \rightarrow Sn \rightarrow 2 CO\), the mass of coke containing \(80 \%\) carbon required to reduce \(0.302 kg\) of pure tin oxide is (Sn=119, \(S =16 C =12)\)

A. \(40 kg\)
B. \(0.20 kg\)
C. \(0.06 kg\)
D. \(0.0 kg\)

Question 817:

The Avogadro nymber of \(24 g\) of magnesium is the same as that of ____________

A. 1g of hydrogen molecules
B. \(16 g\) of oxygen molecules
C. \(12 g\) of carbon molecules
D. \(35.5 g\) of chlorine molecules

Question 818:

If gas ocgúpies a container of volume \(146 cm ^{3}\) at \(18^{\circ} C\) and \(0.971 atm\), its volume in \(cm ^{3}\) at STP is ____________

A. 133
B. 146
C. 266
D. 292

Question 819:

The volume occupied by \(1.58 g\) of a gas at STP is \(500 cm ^{3}\). what is the relative molecular mass of the gas?
(GMV at STP \(=22.40 dm ^{3}\) )

A. 28
B. 32
C. 44
D. 71

Question 820:

Equal volume of \(CO _{2}, SO _{2}, NO _{2}\) and \(H _{2} S\) were released into a room at the same point and time.
Which of the following gives the order of diffusion of the gases to the opposite comer of the room? ( S =32, C =12 ; O =16, N =14, H =1)

A. \(CO , SO _{2}, NO _{2}, H _{2} S
B. \(SO _{2}, NO _{2} SO _{2}, H _{2} S , CO\)
C. \(CO , H _{2} S , SO _{2} NO _{2}\)
D. \(CO , H _{2} S , NO _{2} SO _{2}\)