JAMB Chemistry Past Questions & Answers - Page 206

1,027.

The atomic numbers of two elements X and Y are 12 and 19 respectively. The bond of these two elements is?

A.

ionic

B.

covalent

C.

Metallic

D.

co-ordinate

Correct answer is C

- Both elements are Magnesium and Potassium respectively 

- In general, covalent bonds form between nonmetals, ionic bonds form between metals and nonmetals, and metallic bonds form between metals.

1,028.

If 24.83 cm3 of 0.15 M NaOH is titrated to its end point with 39.45 cm3
of HCl, what is the molarity of the HCl?

A.

0.094 M

B.

0.150 M

C.

0.940 M

D.

1.500 M

Correct answer is A

NaOH + HCl → NaCl + H2O moles ratio = 1/1
↔ (MaVa) / Mb x 39.45 = 0.094

1,029.

In which of the following are the aqueous solutions of each of the substances correctly arranged in order to decreasing acidity?

A.

Ethanoic acid, milk or magnesia, sodium chloride, hydrochloric acid and sodium hydroxide

B.

Ethanoic acid, hydrochloric acid, milk of magnesia, sodium chloride and sodium chloride and sodium hydroxide

C.

Hydrochloride acid, ethanol acid, sodium chloride, milk of magnesia and sodium hydroxide

D.

Hydrochloride acid, sodium hydroxide sodium chloride, ethanol acid, and milk of magnesia

Correct answer is C

No explanation has been provided for this answer.