Chemistry MCQ 12th Standard

(01). Answer key for quiz on chemistry for 12th students

S.N.KeyExplanations
(01).cDipole-dipole interactions are electrostatic interactions between molecules. These have permanent dipoles.
(02).c
(03).bOlefin is known as alkene. It made up of hydrogen and carbon. Hydrogen and carbon contain one or more pairs of carbon. Olefins are examples of unsaturated hydrocarbons.
(04).dVitamin K plays an important role in formation of various proteins that are necessary for blood clotting. It is also needed in building of bones.
(05).cThe Brownian motion typically consists of random fluctuations in a particle’s position inside a fluid. It was renamed after the Scottish botanist Robert Brown.
S.N.KeyExplanations
(06).a
(07).bTyndall effect is observed in a medium in where small particles are suspended. Smoke or dust in a room is an example of Tyndall effect in presence of light.
(08).d
(09).aThe nitrogen atom is hydrogen bond acceptor. It accepts hydrogen from oxygen.
(10).c
S.N.KeyExplanations
(11).cPeriodic table is used in chemistry and physics. The table is divided into four blocks. The rows of the table are periods, and the columns are groups. The first periodic table was made by Russian chemist Dmitri Mendeleev.
(12).c
(13).d
(14).d
(15).a
S.N.KeyExplanations
(16).d
(17).c1. Vitamin A is retinal.
2. Vitamin B1 is thiamine.
3. Vitamin E is tocopherol.
4. Vitamin D is calciferol.
5. Vitamin C is Ascorbic acid.
(18).b
(19).c
(20).a
S.N.KeyExplanations
(21).b
(22).aFrom the definition of Oxford Language Dictionary:

“Protein is any of a class of nitrogenous organic compounds which have large molecules composed of one or more long chains of amino acids”.

“Proteins are an essential part of all living organisms, especially as structural components of body tissues such as muscle, hair, etc., and as enzymes and antibodies”.
(23).d1. Bohr model is also known as Rutherford-Bohr model (1913)..
2.  It consists of a small, dense nucleus surrounded by orbiting electrons.
3. It is similar to the structure of the Solar System.
(24).a
(25).b
S.N.KeyExplanations
(26).c
(27).dNitrogen, phosphorus, and potash are major or macronutrients. Zinc, manganese, boron, molybdenum, iron, etc. are micronutrients.
(28).d
(29).b
(30).a
S.N.KeyExplanations
(31).d
(32).a
(33).a
(34).dHydrolase is a class of enzyme. It is a biochemical catalyst.
(35).b
S.N.KeyExplanations
(36).cThe pH range of blood is about 7.35 to 7.45. Hence it is slightly basic.
(37).a
(38).d
(39).d
(40).aChromatography is a technique of separating components from a mixture. It includes two phase. Mobile phase: Mixture is dissolved in a solvent. Stationery phase: The liquid solvent carries it into a system.
Go to Quiz on chemistry for 12th students

For: Multiple choice objective questions, online mock test, and quiz on chemistry.

This page was last updated on January 07, 2022.