NECO Chemistry Past Questions & Answers - Page 27

131.

A measure of the degree of disorderliness in a chemical system is known as the

A.

activation energy

B.

enthalpy

C.

entropy

D.

equilibrium

E.

free energy.

Correct answer is C

No explanation has been provided for this answer.

132.

Fructose and glucose are

A.

allotropes of each other.

B.

both disaccharides

C.

dimere of each other.

D.

isomers of each other

E.

isotopes of each other

Correct answer is D

No explanation has been provided for this answer.

133.

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.

134.

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.

135.

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.