Post Utme Chemistry Past Questions and Answers

Question 976:

An element \(Y\) has the electronic configuration of \(1 s ^{2} 2 s ^{2} 2 p -\) \(63 s ^{2} 3 p ^{3} .\)

A. \(Y\) is a period III element
B. Y contains three electrons in the outer shell
C. \(Y\) is a transition metal
D. \(Y\) can engage in bonding with the \(s\) and \(p\) orbitals

Question 977:

Which of the following is NOT implicated as a major cause of global warming?

A. \(NO _{2}\)
B. \(CO _{2}\)
C. \(CFCl _{3}\)
D. \(CF _{2} Cl _{2}\)

Question 978:

Which of the following shows little or no net reaction when the volume of the system is decreased?

A. \(2 O _{3( g )} \leftrightarrow 2 HI _{\text {(g) }}\)
B. \(2 NO _{2( g )} \leftrightarrow N _{2} O _{4( g )}\)
C. \(H _{2( g )}+ I _{2( g )} \leftrightarrow 2 HI ( g )\)
D. \(PCl _{5( g )} \leftrightarrow PCl _{3( g )}+ Cl _{2( g )}\)

Question 979:

C \(H _{2( g )}+ I _{2( g )} \leftrightarrow 2 HI ( g ) \quad\) D. \(PCl ( sg ) \leftrightarrow PCl _{3( g )}+ Cl _{2( g )}\)
A solution of \(0.20\) mole of \(NaBr\) and \(0.20\) mole of \(MgBr _{2}\) in \(2.0 dm ^{3}\) of water is to be analysed. How many moles of \(Po \left( NO _{1}\right)_{2}\) must be added to precipitate all the bromide as insoluble \(PbBr _{2}\) ?

A. \(0.30 mol\)
B. \(0.10 mol\)
C. \(0.20 mol\)
D. \(0.40 mol\)

Question 980:

A given volume of methane diffuses in 20 s. How long will it take the same volume of sulphur (IV) oxide to diffuse under the same conditions?
\([ C =12, H =1, S =32, O =\) 16]

A. 5s
B. 20s
C. 40s
D. \(60 s\)