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NECO Chemistry Past Questions & Answers - Page 9

41.

Compound with the general formula CnH2n+2 belong to the_______ group

A.

alkanal

B.

alkane

C.

alkanoate

D.

alkene

E.

alkyne

Correct answer is B

Alkanes have the general formula of CnH2n+2 where n is the number of carbon atoms.

Alkenes have the general formula CnH2n.

The general formula for Alkynes is CnH2n-2.

42.

The process involved in the decomposition of sugar by an enzyme is called

A.

dehydration

B.

esterification

C.

fermentation

D.

polymerization

E.

saponification

Correct answer is C

No explanation has been provided for this answer.

43.

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.

44.

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.

45.

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