Post Utme Obafemi Awolowo University Chemistry Past Questions and Answers

Question 11:

During electrolysis, two cells each containing molten $A{l}_2{O}_3$ and fuse $CaC{l}_2$ were connected in series. A current of $15Amp$ was passed through the cells for a given period of time. At the end of the electrolysis $9g$ of calcium was found to have been deposited at the cathode. What mass of aluminum would be deposited in the second cell. [A = $27,Ca=40]$

A. $8.82g$
B. $4.44g$
C. $17.60g$
D. $4.05g$

Question 12:

The balanced equation for the reaction of tin(II) salt with potassium heptaoxodichloromate (VI) in an acidic medium can be represented as $SS{n}^{2+}+fC{r}_{2}2O_7^{2-}+g{H}^{+}\to hS{n}^{4+}+i-$ $C{r}^{3+}+j{H}_{2}O.$ e, $f,g,i$ and $j$ respectively

A. $3,5,6,1$ and $4$
B. $3,1,14,3,2$ and 7
C. $3,2,6,1,5$ and 6
D. $5,2,1,5,3$ and 2

Question 13:

The $pH$ of a solution containing $0.5\times {10}^{-6}M{H}_{2}S{O}_4$ is ____________

A. $6.3$
B. $6.5$
C. $6.0$
D. $5.0$

Question 14:

Which of the following oxides will NOT dissolve in both dilute hydrochloric acid and $2M$ sodium hydroxide solution?

A. Lead (II) oxide
B. Aluminum oxide
C. Zinc (II) oxide
D. Calcium oxide

Question 15:

The I.U.P . A . C . name for the compound [image] is ____________

A. Pent $-3$ - enoic acid
B. Pent $-4$ - enoic acid
C. Pent 2 - enoic acid
D. Pent $-3$ - ene $-1-$ oic acid