MCQs on a Few Basic Concepts of Chemistry for NEET

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Chemistry is defined as the study of composition, interaction of matter, and properties. Chemistry interlinks to the other branches of science. Also, the principles of chemistry are widely applied. There are a few basic concepts that help us to understand chemistry in a better way. These are the nature, state of a matter, physical and chemical properties, molar and moles mass composition, including various basic laws such as Avogadro’s law, Dalton’s theory, and more. The fundamental concepts of chemistry MCQs help the students to understand the concepts of chemistry in a quick manner.

There are many basic chemistry questions and answers. Some basic concepts of chemistry NEET questions are given below. Let us have a look at it.

Questions on Some Basic Concepts of Chemistry for NEET Concept

1. 10 dm3 of N2 gas, 10 dm3 of gas ‘X’ at a Similar Temperature have the Same Molecule Number. Thus, the Gas X is_______?

(a) CO 

(b) H2

(c) CO2

(d) NO

Answer: (a)


As Molecular mass of CO is 28 and

The molecular mass of N2 is 28

2. The Gram Molecule of Benzene is Equal to_____?

(a) 10 g C6H6

(b)70 g C6H6 

(c) 72 g C6H6

(d) 78 g C6H6

Answer: (d)


The molecular formula of benzene is C6H6.

Therefore, the molecular mass is the sum of the atomic weight of all the atoms

Thus, the molecular mass = 12 × 6 + 6 × 1

 = 72 + 6

 = 78

Thus, as per the Avogadro’s number, the gram molecules of benzene is equal to 78 g of C6H6

3. Under the Same Conditions, Nitrogen and Oxygen are Taken in the Same Mass. The Ratio of Their Volumes will be _____

(a) 7 : 8 

(b) 9 : 2

(c) 5 : 6

(d) 3 : 5

Answer: (a)


Nitrogen (14) : Oxygen (16)

Therefore, the Ratio is 7 : 8

4. Recently the Unit of Atomic Mass “amu” is replaced by______

(a) u

(b) mol

(c) g 

(d) kg

Answer: (a)


u is meant by unified mass. 

5. According to Avogadro’s law___

(A) V ∝ 1P 

(B) V ∝ n

(C) V ∝ T

(D) All the above

Answer: (b)


Volume of gas is always directly proportional to the number of molecules

6. Which of the Following Statements about a Compound is Incorrect One?

(a) A molecule of a compound has atoms with different elements.

(b) The ratio of atoms of different elements in a compound is fixed

(c) A compound retains physical properties of its associated constituent elements

(d) A compound cannot be separated into its constituent elements by physical methods of separation

Answer: (c)

7. If the Density of Oxygen (O2) gas at NTP is 1.429g/L, Calculate the Standard Molar Volume of the Oxygen Gas.

(a) 22.39litres

(b) 25 Litres

(c) 21.2 Litres

(d) None of the above

Answer: (a)

8. Calculate the Number of Oxygen Atoms in 50 g of CaCO3

(a) 6.033 × 1023 atoms

(b) 9.033 × 1023 atoms

(c) 8.033 × 1023 atoms

(d) 3.033 × 1023 atoms

Answer: (b)

9. The Mass of 2.044 × 10 23 Carbon Atoms is Given by_____

(a) 15 g

(b) 38 g

(c) 24 g

(d) 48 g

Answer: (c)

10. How Many Grams of Solute is Needed to Prepare 1.0 L of 1 M CaCl2.6H2O?

(a) 200 g

(b) 216 g

(c) 219 g

(d) None of the above

Answer: (c)

11. According to the Law of Conservation of Mass., Which of the Following Reactions is not Correct?

(a) 2Mg(s) + O2 (g) → 2MgO(s)

(b) C3H8(g) + O2 (g) → CO2(g) + H2O(g)

(c) CH4(g) + 2O2(g) → CO2(g) + 2H2O(g)

(d) P4(s) + 5O2(g) → P4O10(s)

Answer: (b)

12. How Many ml of Water Must be Added to 200 ml of .65 M HCL to Further Dilute the Solution to .20 M?

(a) 450 ml

(b) 750 ml

(c) 550 ml

(d) 500 ml

Answer: (a)

13. Calculate the Number of Gram Molecules of Oxygen in 6.02 × 10 2 4 CO Molecules.

(a) 10 gm molecules

(b) 5 gm molecules

(c) .1 gm molecules

(d) .5 gm molecules

Answer: (b)

14. Which of the Following one has the Largest Number of Atoms?

(a) 0.5 g atoms of Cu

(b) 0.635 g Cu

(c) 0.25moles of Cu atoms

(d) 1g of Cu

Answer: (a)

15. A Measured Temperature on the Fahrenheit Scale is 200 °F. What will This Reading be on the Celsius Scale?

(a) 45° C

(b) 93° C

(c) 93.3° C

(d) 35° C

Answer: (c)

16. The Elements X, Y Combine to Form Two Compounds as XY and X2Y. Find the Atomic Weight of X and Y, When the Weight of 0.1 Moles of XY is 10g and 0.05 Moles of X2Y is 9g.

(a) 60, 40

(b) 80, 20

(c) 30, 20

(d) 20, 30

Answer: (b)

17. Which One will have Maximum Numbers of Water Molecules?

(a) 18 molecules of water

(b) 18 grams of water

(c) 1.8 grams of water

(d) 18 moles of water

Answer: (d)

FAQ (Frequently Asked Questions)

1. The Number of Atoms that are Present in 0.1 Moles of a Triatomic Gas is____

(a) 1.806 × 1023

(b) 3.600 × 1023

(c) 1.806 × 1022

(d) 6.026 × 1022

Answer: (a)

2. A gas ‘X’ has the Cp and Cv Ratio as 1.4, at NTP 11.2 L of Gas X will Contain how many Atoms?

(a) 3.01 × 1023

(b) 1.2 × 1023

(c) 2.01 × 1023

(d) 6.02 × 1023

Answer: (d)

3.The Pressure has the Same Dimension as ____

(a) energy per unit volume

(b) energy

(c) force per unit volume

(d) force

Answer: (a)

4. There are Two Chlorides of Sulphur S2Cl2 and SCl2. What is the Equivalent Mass of SCl2 ?

(a) 8 g/mole

(b) 64.8 g/mole

(c) 16 g/mole

(d) 6 g/mole

Answer: (c)

5. Boron exists as Two Stable Isotopes as, 10B (19%) and 11B (81%). Find out the Average Atomic Weight of Boron as per the Periodic Table.

(a) 10.0

(b) 10.5

(c) 11.4

(d) 10.8

Answer: (d)

6. Which of the Following Terms is Unitless?

(a) Molarity

(b) Molality

(c) Mass percent

(d) Mole fraction

Answer: (c), (d)