Post Utme Chemistry Past Questions and Answers

Question 936:

An organic compound with the molecular of \(C _{4} H _{8} O\) has the isomers (i) butanal (ii) cyclobutanol (iii) cyclobutanone (iv) 2 - methylpropanal

A. (i) and (ii)
B. (i), (ii) and (iv)
C. (i), (ii) and (iii)
D. (ii) and (iv)

Question 937:

\(0.125 mol\) of magnesium is dropped into \(25 cm ^{3}\) of \(4.0 moldm ^{-3} HCl\), how many moles of hydrogen gas are evolved?
[ Mg =24]

A. 0 .050
B. 0.250
C. \(0.125\)
D. \(0.063\)

Question 938:

Which of the followings is thermally stable?

A. \(CuCO _{3}\)
B. \(Pb \left( NO _{3}\right)_{2}\)
C. \(NaNO _{3}\)
D. \(Na _{2} CO _{3}\)

Question 939:

An atom has a core and outside the core an electron occupies an orbital for which the principal quantum number, \(n\) \(=4,1=0, m=0\) and \(s=+1 / 2\) or \(-1 / 2\). The atom is likely to be ____________

A. Boron
B. Sodium
C. Potassium
D. Fluorine

Question 940:

An element \(B\), has two isotopes \({ }_{10}^{20} B\) and \({ }_{10}^{22} R\) present in ratio \(2: 3\). The relative atomic mass of \(B\) is ____________

A. \(20.5\)
B. \(21.2\)
C. \(23.4\)
D. \(25.0\)