Chemistry questions and answers

Chemistry Questions and Answers

Learn more about the properties, composition, and structure of substances (elements and compounds) with these Chemistry questions and answers. This Test can be used by students preparing for Chemistry in JAMB, WAEC, NECO or Post UTME.

2,801.

In the reaction of oxygen with hydrogen to produce water, which of the following statements is true?

A.

One atom of hydrogen reacts with two atoms of oxygen to give one molecule of water

B.

Two atoms of hydrogen react with two atoms of oxygen to give two molecules of water

C.

One molecule of oxygen reacts with one molecule of hydrogen to give two molecules of water

D.

One molecule of hydrogen reaccts with two molecules of oxygen to give three molecules of water

E.

One molecule of oxygen reacts with two molecules of hydrogen to give two molecules of water

Correct answer is E

The oxidation of hydrogen by oxygen gives water and a certain amount of heat of formation.

2,802.

Which of the following is the electronic configuration of sodium?
(Atomic number of Na = 11)

A.

1s2 2s22p6 3s2

B.

1s2 2s22p6 3s2 3p1s2 2s22p6 3s1

C.

1s2 2s22p6 3s1

D.

1s2 2s22p6 3s°

E.

1s2 2s22p6 4s1

Correct answer is C

No explanation has been provided for this answer.

2,803.

A polymerization reaction is one in which?

A.

small molecules form giant molecules

B.

atoms form molecules

C.

giant molecules form small molecules

D.

molecules form volatile compounds

E.

a molecule rearranges itself

Correct answer is A

No explanation has been provided for this answer.

2,804.

Allotropes are elements having?

A.

different physical but the same chemical properties

B.

different chemical but the same physical properties

C.

the same chemical and physical properties

D.

different atomic structure

E.

the same position in the periodic table

Correct answer is A

Allotropes: These are the different forms of elements having different physical properties but the same chemical properties.

For example, the allotropes of carbon. Crystalline form: Diamond, Graphite and Fullerene

2,805.

Which of the following can have an isomer?

A.

C2H4

B.

C4H10

C.

C3H8

D.

C2H6

E.

C6H6

Correct answer is B

Butane is an alkane with four carbon atoms so molecular formula is C4H10. It has two isomers; n-butane and isobutane.