WAEC Past Questions and Answers - Page 1615

8,071.

Acidic industrial waste can be treated with

A.

lime

B.

brine

C.

water

D.

enthanol

Correct answer is A

No explanation has been provided for this answer.

8,072.

Which of the following reactions represents the change that occurs when a photographic film is exposed to sunlight?

A.

Ag → Ag+ + e-

B.

Ag+ + e- → Ag

C.

2Ag + Br22 → AgBr

D.

Ag+ + Br- → AgBr

Correct answer is B

No explanation has been provided for this answer.

8,073.

If 10 cm 3 of distilled water is added to 10 cm3 of an aqueous salt solution, the concentration of the solution

A.

increases

B.

decreases

C.

remains constant

D.

doubles

Correct answer is B

No explanation has been provided for this answer.

8,074.

Sugars can be hydrolyzed at room temperature by the action of

A.

mineral acids

B.

strong bases

C.

enzymes

D.

oxidants

Correct answer is C

Simple sugar molecules (monosaccharide ) when combined to form larger molecules (dissacharides or polysaccharides) is called condenation , water molecules is generated in the process, the reverse process is known as hydrolysis. sugar can be hydrolyszed at room temperature by the action of enzymes.

8,075.

Which of the following constitutes an advantage in the use of hard water?

A.

Formation of scum with soap

B.

Furring of kettles

C.

Blockage of water pipes

D.

Formation of strong bones

Correct answer is D

No explanation has been provided for this answer.