JAMB Chemistry Past Questions & Answers - Page 161

801.

H 2O (g) + C (s) → H2(g) + CO(g)

The oxidizing agent in the reaction above is

A.

CO(g)

B.

C(s)

C.

H2O(g)

D.

H(2)(g)

Correct answer is C

No explanation has been provided for this answer.

802.

Zn (s) + CuSO 4(aq) → ZnSO 4(aq) + Cu (s)
In the reaction above, the oxidation number of the reducing agent changes from

A.

0 to + 4

B.

0 to + 2

C.

+ 1 to + 2

D.

+ 1 to + 3

Correct answer is B

No explanation has been provided for this answer.

803.

Which of the following salts will turn blue litmus red?

A.

Sodium tetrahydroxozincate (ll)

B.

Sodium hydrogentetraoxosulphate (VI)

C.

Sodium trioxocarbonate (lV)

D.

Zinc chloride hydroxide

Correct answer is B

No explanation has been provided for this answer.

804.

The mathematical expression of PH is

A.

log 10[OH-]

B.

log 101/[H 3 O+]

C.

log 10[H 3 O+]

D.

log 101/[OH -]

Correct answer is B

No explanation has been provided for this answer.

805.

The colour of litmus in a neutral medium is

A.

purple

B.

pink

C.

yellow

D.

orange

Correct answer is A

The colour of a neutral litmus solution is purple.

Litmus solution is made up of purple dye which is extracted from Lichens.

It is a natural Indicator and it is used to indicate the presence of an acid or a base.

A litmus paper will turn red in the presence of an acid and it turns blue in the presence of a base.