JEE Mains 2023 : Best Question Collection in Chemistry | JEE Main Chemistry Test Series-1

1. The polymer formed on heating Novolac with formaldehyde is :

2. Which one of the following methods is most suitable for preparing deionized water ?

3. Which one of the following is correct for the adsorption of a gas at a given temperature on a solid surface ?

4. Given below are two statements :
Statements I : According to Bohr’s model of an atom, qualitatively the magnitude of velocity of electron increases with decre ase in positive charges on the nucleus as there is no strong hold on the electron by the nucleus.

Statement II : According to Bohr’s model of an atom, qualitatively the magnitude of velocity of electron increases with decrease in principal quantum number. In the light of the above statements, choose the most appropriate answer from the options given below :

5. These are physical properties of an elements.

6. Compound A is converted to B on reaction with CHCl₃ and KOH. The compound B is toxic and can be decomposed by C. A, B and C respectively are :

7. The metal that can be purified economically by fractional distillation method is:

8. The conditions given below are in the context of observing Tyndall effect in colloidal solutions:

(A) The diameter of the colloidal particles is comparable to the wavelength of light used.
(B) The diameter of the colloidal particles is much smaller than the wavelength of light used.
(C) The diameter of the colloidal particles is much larger than the wavelength of light used.
(D) The refractive indices of the dispersed phase and the dispersion medium are comparable.
(E) The dispersed phase has a very different refractive index from the dispersion medium

Choose the most appropriate conditions from the options given below:

9. Given below are two statements : One is labelled as Assertion A and other is labelled as Reason R. Assertion A : The dihedral angles in H,O, in gaseous phase is 90.2° and in solid phase is 111.5°

Reason R : The change in dihedral angle in solid and gaseous phase is due to the difference in the intermolecular forces. Choose the most appropriate answer from the options given below for A and R.

10. Orlon fibres are made up of:

11. Identify the incorrect statement from the following:

12. Given below are two statements. One is labelled as Assertion A and the other is labelled as Reason R.
Assertion A : Sharp glass edge becomes smooth on heating it upto its melting point.
Reason R : The viscosity of glass decreases on melting.
Choose the most appropriate answer from the options given below.

13. A s-block element (M) reacts with oxygen to form an oxide of the formula MO₂. The oxide is pale yellow in colour and paramagnetic. The element (M) is :

14. In chromatography technique, the purification of compound is independent of:

15. Which among the following pairs of Vitamins is stored in our body relatively for longer duration ?