WAEC Chemistry Past Questions & Answers - Page 88

436.

Which of these radioactive elements is commonly used as a nuclear fuel

A.

uranium

B.

palladium

C.

actium

D.

thorium

Correct answer is A

Uranium is common nuclear because of its less stability as a result has a great tendency to increase energy than. Options B,C,D which are not stable

437.

A major source of oxide of nitrogen is from the burning of

A.

coal

B.

wood

C.

fuel

D.

chlorofluorocarbons

Correct answer is C

No explanation has been provided for this answer.

438.

Which of the following ions  requires the largest quantity of electricity for discharge at an electrode?

A.

2.0 mole of Q3+

B.

2.5 mole of R2+

C.

3.0 mole of T-

D.

4.0 mole of Y-

Correct answer is A

2.0 mole of Q3+ ions require the largest quantity of electricity for discharge at an electric. option B,C,D are all carrying a smaller quantity of electricity which not be proven for ant discharge

439.

P1V1 = P2V2 supports ?

A.

Charles’s law

B.

Boyles’s law

C.

Graham’s law

D.

Avogadro’s law

Correct answer is B

V = 1/P

cross multiply

K = VP

V1P1 = V2V2

For a fixed amount of an ideal gas kept at a fixed temperature, pressure and volume are inversely proportional. Or Boyle's law is a gas law, stating that the pressure and volume of a gas have an inverse relationship, when temperature is held constant.
The equations supports only Boyle’s law. Option A,C,D are not in support of the equation...

440.

A suitable reagent for distinguish between ethanoic and ethanol is

A.

bromine water

B.

Fehling’s solution

C.

sodium hydrogen trioxocarbonate (iv)

D.

Ammoniacal silver trioxonitrate(V)

Correct answer is C

Sodium hydrogen trionocarbonate iv is the only distinguishing reagent between ethanoic and ethanol. Option A, B, D are not conspicuous in distinguishing between ethanoic and ethanol