250+ TOP MCQs on p-Block Elements – Important Compounds of Carbon and Silicon and Answers

Chemistry Multiple Choice Questions on “p-Block Elements – Important Compounds of Carbon and Silicon”.

1. Which of the following mixture is known as producer gas?
a) carbon dioxide and hydrogen
b) carbon monoxide and hydrogen
c) carbon monoxide and nitrogen
d) carbon dioxide and nitrogen
Answer: c
Clarification: The mixture of carbon monoxide and nitrogen is known as producer gas and the mixture of carbon monoxide and hydrogen known as water gas. At 1273 K carbon combines with oxygen and nitrogen in order to form producer gas.

2. Which of the following is not a property of carbon monoxide?
a) odourless
b) colourless
c) water-insoluble
d) oxidising agent
Answer: d
Clarification: Carbon monoxide is a colourless, odourless and almost water-insoluble gas. It is a powerful reducing agent. It is also used in the extraction of many metals from their oxide ores like ferrous oxide and zinc oxide.

3. Carbon dioxide forms carbonic acid with water.
a) true
b) false
Answer: a
Clarification: Carbon dioxide is given chemically by CO₂ and it is a colourless and odourless gas with water, it forms carbonic acid. The chemically balanced equation is given as H₂CO_3(aq) + H₂O → HCO₃^– + H₃O⁺.

4. What is the basic structural unit of a silicate?
a) Si₄^–
b) SiO^–
c) SiO₄
d) SiO₄^4-
Answer: d
Clarification: Silicates are the metal derivatives of silicic acid, H₂SiO₃ and can be obtained by fusing metal oxides or metal carbonates with sand. The basic structural unit of silicates is SiO₄^4-. An example is Zircon (ZrSiO₄).

5. What is the chemical formula of beryl?
a) Be₃Al₂Si₆O₁₈
b) Be₃AlSi₆O₁₈
c) Be₃Al₂Si₆O
d) BeAl₂Si₆O₁₈
Answer: a
Clarification: The chemical formula of beryl is given as Be₃Al₂Si₆O₁₈. Beryl is a type of cyclic silicate and it has two oxygen atoms shared and the basic unit is Si₆O₁₈^12-. It is known as beryllium aluminium cyclosilicate.

6. Talcum powder has a slippery touch.
a) True
b) False
Answer: a
Clarification: Talc consists of planar sheets which can slip over one another due to the weak forces of attraction and it is a constituent of talcum powder. That’s the reason why talcum powder has a slippery touch, So the above statement can be considered to be true.

7. What is the second hardest material known?
a) Coke
b) Carborundum
c) Graphite
d) Diamond
Answer: b
Clarification: Carborundum is the second hardest material known and has a formula of silicon carbide that is SiC. It is used as a semiconductor at high-temperature and also in transistor diode rectifiers. Diamond is the first hardest material known.

8. The cross-linked polymer compounds containing silicone which are linear and the cyclic are called ___________
a) coal
b) silicones
c) silicate
d) silicanes
Answer: b
Clarification: The linear, cyclic or cross-linked polymer compounds containing R₂SiO, as a repeating unit, is known as Silicones. They are manufactured from alkyl substituted chlorosilanes they are chemically inert, water repellent and also heat resistant.

9. Which of the following is not a component of glass?
a) Sodium chloride
b) Calcium carbonate
c) Silica
d) Sodium carbonate
Answer: a
Clarification: Glass is a transparent or translucent amorphous substance, which is obtained by fusion of sodium carbonate or sodium sulphate, calcium carbonate and sand (which is also known as silica), the general formula of glass is Na₂O.CaO.6SiO₂

10. When aluminium ions replace silicon ions and silicon dioxide what is it called?
a) silicanes
b) silicates
c) silicons
d) zeolites
Answer: d
Clarification: When aluminium ions replace few ions in a three-dimensional network of silicon dioxide, the overall structure is known as aluminosilicate and it also requires negative charge cations like sodium, potassium or calcium to balance negative charge. Few examples are zeolites and feldspar.

11. which of the following is not a part of the composition of natural gas?
a) hydrocarbons
b) methane
c) ethane
d) benzene
Answer: d
Clarification: Natural gas is found along with petroleum below the surface of the earth, its composition is methane, higher hydrocarbons, ethane and propane. It is used as a fuel and its combustion is carbon black which is a reinforcing agent for rubber.

12. What is the full form of LPG?
a) liquefied phenolic gas
b) liquefied pentane gas
c) liquefied petroleum gas
d) liquid petroleum gas
Answer: c
Clarification: The full form of LPG is liquefied petroleum gas and its composition is N-butane and isobutene. It is used as a domestic fuel. LPG, that is liquefied petroleum gas is commonly used in household for cooking.