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.

1,091.

Detergents are better than soaps for washing in hard water because

A.

hard water contains insoluble calcium salts.

B.

they contain bleaching powder.

C.

they contain palmitic acid.

D.

they do not form insoluble calcium and magnesium salts.

E.

they are organic compounds.

Correct answer is D

No explanation has been provided for this answer.

1,092.

Which method is NOT used to determine rate of a reaction?

A.

change in amount of precipitate formed

B.

change in equilibrium constant

C.

change in intensity of colour

D.

change in pH values.

E.

change in total gas pressure

Correct answer is B

No explanation has been provided for this answer.

1,093.

Ethanol is a product of fermentation of simple sugars. Which method is used to separate ethanol from the other products?

A.

boiling off the ethanoic

B.

filtration

C.

fractional crystallisation

D.

fractional distillation

E.

isomerisation

Correct answer is D

No explanation has been provided for this answer.

1,094.

To test for the presence of chloride ions in ion, correct sequence of reagents to use is

A.

Ba(NO3)2(aq) then HNO3(aq).

B.

HCl(aq) then Ba(NO3)2(aq).

C.

HCl(aq) then Ag3(aq).

D.

HNO3(aq) then fresh FeSO4(aq).

E.

HNO3(aq) then AgNO3(aq).

Correct answer is E

No explanation has been provided for this answer.

1,095.

NaCl(s) does NOT conduct electricity, but N(aq) does. This is because

A.

NaCl(s) is non-ionic but NaCl(aq) is ion

B.

NaCl(aq) contains mobile electrons, where absent in NaCl(s).

C.

NaCl(aq) contains mobile ions which Nacl,) does not contain.

D.

NaCl(s) ionizes partiality while NaCl(aq) iodizes completely.

E.

NaCl(s) decomposes when heated but NCl(aq) is stable to heat.

Correct answer is C

No explanation has been provided for this answer.