NECO Past Questions and Answers - Page 88

436.

The following gases are diatomic EXCEPT

A.

Fluorine

B.

Helium

C.

Hydrogen

D.

Nitrogen

E.

Oxygen

Correct answer is B

No explanation has been provided for this answer.

437.

If two elements X and Z with electronic configurations 2,8.3 and2,8,6 respectively combine, the compound formed will have the formula

A.

XZ

B.

XZ2

C.

X2Z

D.

X2Z3

E.

X3Z2

Correct answer is D

No explanation has been provided for this answer.

438.

The reaction of hydrochloric acid and calcium trioxocarbonate (IV) produces

A.

calcium chloride, carbon (IV) oxide and water

B.

calcium chloride, and trioxocarbonate (IV) acid

C.

calcium hydroxide, carbon (IV) oxide and chlorine gas

D.

calcium hydroxide, carbon (IV) oxide and water

E.

calcium metal and water.

Correct answer is A

No explanation has been provided for this answer.

439.

Brownian motion explains

A.

Boyle’s law

B.

Collision theory

C.

Laws of chemical combination

D.

Molecular motion in liquids and gases

E.

Vibrational motion in liquids.

Correct answer is D

No explanation has been provided for this answer.

440.

A chemical system is at equilibrium when

A.

δ G is positive

B.

δ G is zero

C.

δ S is negative

D.

δ S is positive

E.

δ S is zero.

Correct answer is B

No explanation has been provided for this answer.