Science 4

31.

Potassium nitrate is used in

A. medicine

B. fertiliser

C. salt

D. glass

Answer: Option B

32.

Permanent hardness of water may be removed by the addition of

A. sodium carbonate

B. alum

C. potassium permanganate

D. lime

Answer: Option A

33.

Soda water contains

A. carbonic acid

B. sulphuric acid

C. carbon dioxide

D. nitrous acid

Answer: Option C

34.

The most important ore of aluminium is

A. galena

B. calamine

C. calcite

D. bauxite

Answer: Option D

35.

Most soluble in water is

A. camphor

B. sulphur

C. common salt

D. sugar

Answer: Option D

36.

Which of the following was to be discovered first in the chromospheres of the sun?

A. Krypton

B. Xenon

C. Neon

D. Helium

Answer: Option D

37.

Which of the following is in liquid form at room temperature?

A. Lithium

B. Sodium

C. Francium

D. Cerium

Answer: Option C

38.

Sodium metal is kept under

A. petrol

B. alcohol

C. water

D. kerosene

Answer: Option D

39.

Which of the following are the ingredients of gun metal?

A. Iron, Zinc, Titanium

B. Iron, tin

C. Iron, Brass, Tin

D. Copper, Tin

Answer: Option D

40.

From which mineral is radium obtained?

A. Rutile

B. Haematite

C. Limestone

D. Pitchblende

Answer: Option D

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