Post Utme Chemistry Past Questions and Answers

Question 986:

An aqueous solution of a crystalline salt reacts with dilute \(HCl\) to give a yellow precipitate and a gas that turned dichloromate paper green. The crystalline salt may be, ____________

A. \(Na _{2} S _{2} O _{3} \cdot 5 H _{2} O\)
B. \(Na _{2} CO _{3} \cdot 10 H _{2} O \)
C . Na _{2} S\)
C. \(NaHCO _{3}\)

Question 987:

The oxidation states of nitrogen in ammonium nitrate are, ____________

A. \(-3,+3\)
B. \(-3,+5\)
C. \(+3,-5\)
D. \(-3,+4\)

Question 988:

Which of these reagents can confirm the presence of a triple bond?

A. Hypochlorous acid
B. Bromine water
C. Acidified \(KMnO _{4}\)
D. Copper chloride

Question 989:

\({ }_{88}^{226} Ra \rightarrow{ }_{86}^{x} Rn +\alpha\) - particle. What is the value of \(x\) in the nuclear reaction?

A. 226
B. 220
C. 222
D. 174

Question 990:

In the electrolysis of copper (II) sulphate using copper electrodes, the processes that occur at the anode and cathode respectively are, ____________

A. Dissolution and evolution
B. Dissolution and deposition
C. Deposition and evolution
D. Evolution and deposition