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.

411.

What mass of water is produced when 8.0g of hydrogen reacts with excess oxygen?

A.

8.0g

B.

16.0g

C.

36.0g

D.

72.0g

Correct answer is D

2H\(_2\) + O\(_2\)  ⇒ 2H\(_2\)O

From the equation:

4g of Hydrogen produces 36g of water

: 8g of Hydrogen will produce 72g of water

412.

The chlorinated alkane often used industrially to remove grease is?

A.

Tetrachloromethane

B.

Chloromethane

C.

Trichloromethane

D.

Dichloromethane

Correct answer is A

Tetrachloromethane ( carbon tetrachloride) is an effective solvent within the chemical industry and is used to clean machinery and electrical equipment. 

I.e as a solvent for oils, fats, lacquers, varnishes, rubber waxes, and resins, and as a grain fumigant.

413.

The substance often used for vulcanization of rubber is?

A.

Chlorine

B.

Hydrogen peroxide

C.

Sulphur

D.

Tetraoxosulphate(vi) acid

Correct answer is C

One of the several uses of sulfur is for the vulcanization of rubber.

414.

An organic compound that does not undergo a reaction with both hydrogen cyanide and hydroxylamine can be?

A.

Alkene

B.

Alkanal

C.

Alkanone

D.

Alkanoic Acid

Correct answer is A

Alkanone & alkanal react with HCN to form compounds known as cyanohyderins. They also react with hydroxylamine to form oximes.

415.

Which of the following types of bonding does not involve the formation of new substances?

A.

Metallic

B.

Covalent

C.

Co-ordinate

D.

Electrovalent

Correct answer is A

Metallic bond does not involve the formation of a new substance. It is responsible for several characteristic properties of metals such as their shiny lustre, their malleability, and their conductivities for heat and electricity