JAMB Chemistry Past Questions & Answers - Page 427

2,131.

What properties of duralumin make it more useful than its constituent metals?

A.

It is heavy with a high melting point

B.

It is malleable and has high density

C.

It is strong and light

D.

It is hard and ductile

Correct answer is C

No explanation has been provided for this answer.

2,132.

Hydrogen is used in oxy-hydrogen flames for melting metals because it

A.

evolves a lot of heat when burnt

B.

combines explosively with oxygen

C.

is a very light gas

D.

is a rocket fuel

Correct answer is A

No explanation has been provided for this answer.

2,133.

A pair of compounds that can be used to generate a gas which has physiological effect on human beings is

A.

sodium trioxonitrate (V) and calcium chloride

B.

sodium dioxonitrate (III) and ammonium chloride

C.

sodium trioxonitrate (V) and ammonium chloride

D.

sodium dioxonitrate (III) and potassium chloride

Correct answer is C

The reaction between NaNO\(_3\) and NH\(_4\)Cl gives NaCl and NH\(_4\)NO\(_3\).

Upon heating, NH\(_4\)NO\(_3\) yields 2 moles of H\(_2\)O and N\(_2\)O.

2,135.

Chlorine, bromine and iodine resemble one another in that they?

A.

dissolve in alkalis

B.

react violently with hydorgen without heating

C.

are liquids

D.

displace one another from solutiions of their salts

Correct answer is D

Halogens undergo displacement reactions with halides solutions. A more reactive halogen can displace a less reactive halogen from its halide