set 3 MCQ Questions & Answers Detailed Explanation

Question : 1

Iron sheet kept in moist air covered with rust. Rust is

a) a mixture of iron and dust

b) an element

c) a compound

d) a mixture of iron, oxygen and water

Question : 2

The chemical formula of Borax is

a) BaS$O_4$

b) $Na_2B_4O_7$

c) CaOC$l_2$

d) Ca$(SO_4)_2$

Question : 3

The main of component of Biogas is

a) Propane

b) Methane

c) Ethane

d) Butane

Question : 4

Iodised salt is a

a) compound formed by combination of potassium iodide and common salt

b) mixture of potassium iodide and common salt

c) mixture of molecular iodide and common salt

d) compound formed by molecular iodine and common salt

Question : 5

Which of the following is a good lubricant ?

a) Molten carbon

b) Diamond powder

c) Graphite powder

d) Alloy of carbon and iron

Question : 6

A mixture of ethanol and water can be separated by

a) fractional distillation

b) decantation

c) filtration

d) sublimation