NECO Chemistry Past Questions & Answers - Page 10

46.

Which of the following equations is NOT balanced?

A.

CH4(g) + 202(9) → CO2(g) + 2H2O(g)

B.

CU(S) + HNO3(aq) → Cu(NO3)2(aq) + 4H2O(I) + NO(g)

C.

2KCIO3(s) → 2KCI(s)+ 3O2(g)

D.

NaH(s) + H2O(1) → NaOH(aq) +H2(g)

E.

Na2SO4(aq) + BaCl2(aq) → BaSO4(s) + 2NaCl(aq)

Correct answer is B

No explanation has been provided for this answer.

47.

A colourless gas with characteristics odour which dissolves in water to form an alkaline solution is

A.

ammonia

B.

carbon(IV)oxide

C.

hydrogen chloride

D.

sulphur (IV) oxide

E.

sulphur (VI) oxide

Correct answer is A

No explanation has been provided for this answer.

48.

In which of the following equations can Le-chartelier’s principle be applied?

A.

H2(g)+S(g) → H2(g)

B.

2H2S(g) + O2 (g) → 2H2O(l) + 2SO2(g)

C.

N2(g) +3H2(g) ⇌ 2NH3(g)

D.

NaOH(aq) +CO2(g) → Na2CO3(aq) + H2O(l)

E.

S(s) + 02(g) → SO2(g)

Correct answer is C

According to Le Chatelier's Principle, this will be favored if you lower the temperature. The system will respond by moving the position of equilibrium to counteract this - in other words by producing more heat. To get as much ammonia as possible in the equilibrium mixture, you need as low a temperature as possible

49.

In which of these groups will all the substances be insoluble in water?

A.

Na2CO3, KNO3,(NH4)2C03

B.

NaHCO3, PbSO4, CaSO4

C.

K2C03, CaSO4, AgNO3

D.

PbCl2, NaCl, ZnCl2

E.

ZnCO3, BaSO4,AgCl

Correct answer is E

No explanation has been provided for this answer.

50.

What is the maximum number of electrons that an f-orbital can accommodate?

A.

2

B.

6

C.

7

D.

10

E.

14

Correct answer is E

No explanation has been provided for this answer.