Chemistry questions and answers

Chemistry Questions and Answers

Learn more about the properties, composition, and structure of substances (elements and compounds) with these Chemistry questions and answers. This Test can be used by students preparing for Chemistry in JAMB, WAEC, NECO or Post UTME.

946.

The following compounds decolorize acidified potassium tetraoxomanganate (VII) solution EXCEPT

A.

HOCH2 – CH2OH

B.

H2C –C =C– CH3

C.

H3C – HC = CH2

D.

H2C = CH2

E.

H3C – C =CH

Correct answer is A

No explanation has been provided for this answer.

947.

The percentage composition of a hydrocarbon is 79.2 carbon 20.8 hydrogen. Calculate its empirical formula [H = 1, C = 12]

A.

CH

B.

CH3

C.

CH4

D.

C2H2

E.

C2H6

Correct answer is B

Relative No of Moles for Carbon = 79.2% ÷ 12 = 6.6

Relative No of Moles for Hydrogen = 20.8% ÷ 1 = 20.8

Ratio of Moles = Carbon 6.6 ÷ 6.6 = 1                 Hydrogen = 20.8 ÷ 6.6 ~ 3

EMPIRICAL FORMULA IS      CH\(_3\)

948.

Compound with the general formula CnH\(_{2n+2}\) 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.

949.

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.

950.

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.