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.

2,846.

Potassium tetraoxomanganate (VII) is often added to impure water to?

A.

reduce organic impurities

B.

reduce inorganic impurities

C.

destroy bacteria and algae

D.

remove permanent hardness

Correct answer is C

Potassium permanganate is a point-of-entry treatment method that oxidizes dissolved iron, manganese, and hydrogen sulfide into solid particles that are filtered out of the water. It can also be used to control iron bacteria growth in wells.

2,847.

The property used in obtaining oxygen and nitrogen industrially from air is the?

A.

boiling point

B.

density

C.

rate of diffusion

D.

solubility

Correct answer is A

No explanation has been provided for this answer.

2,848.

The line observed in the sample hydrogen spectrum are due to emission of?

A.

electrons from the atoms

B.

energy by proton transition

C.

energy by electron transition

D.

neutron from the atom

Correct answer is C

No explanation has been provided for this answer.

2,849.

Which of the following electron configurations indicates an atom with the highest ionization energy?

A.

2,8,7

B.

2,8,8,1

C.

2,8,8,2

D.

2,8,8,7

Correct answer is A

No explanation has been provided for this answer.

2,850.

A solid begins to melt when?

A.

constituent particles acquires a greater kinetic energy

B.

energy of vibration of particles of the solid is less than the intermolecular forces

C.

constituent particles acquires energy above the average kinetic energy

D.

energy of vibration of particles of the solid equals the intermolecular forces

Correct answer is D

When a solid is heated, the particles are given more energy and start to vibrate faster. At a certain temperature, the particles vibrate so much that their ordered structure breaks down. At this point the solid melts into liquid.