दोस्तों यहां पर JEE Main 2021 20th July Shift 1 Chemistry का Solved Paper दिया गया है तथा आपको JEE Main का ऑनलाइन टेस्ट भी इस वेबसाइट पर दिया गया है।
| Section A |
1. 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 :
(1) secondary amine, nitrile compound, conc. NaOH
(2) primary amine, isonitrile compound, conc. HC1
(3) secondary amine, isonitrile compound, conc. NaOH
(4) primary amine, nitrile compound, conc. НСl
2. According to the valence bond theory, the hybridization of central metal atom is dsp² for which one of the following compounds ?
(1) Na₂[NiCl₄]
(2) NiCl₂.6H₂O
(3) K₂[Ni(CN)₄]
(4) [Ni(CO)₄]
3. The set in which compounds have different nature is :
(1) B(OH)₃ and H₃PO₃
(2) B(OH)₃ and Al(OH)3
(3) NaOH and Ca(OH)₂
(4) Be(OH)₂ and Al(OH)₃
4. 
For above chemical reactions, identify the correct statement from the following:
(1) compound ‘A’ is di-carboxylic acid and compound ‘B’ is diol
(2) compound ‘A’ is diol and compound ‘B’ is di-carboxylic acid
(3) both compound ‘A’ and compound ‘B” are diols
(4) both compound ‘A’ and compound ‘B’ are di-carboxylic acids
5. 
Which among the above compound/s does/ do not form Silver mirror when treated with Tollen’s reagent ?
(1) Only (II)
(2) (I), (III) and (IV) only
(3) (III) and (IV) only
(4) Only (IV)
6. Green chemistry in day-to-day life is in the use of:
(1) chlorine for bleaching of paper.
(2) liquified CO₂ for dry cleaning of clothes.
(3) large amount of water alone for washing clothes.
(4) tetrachloroethene for laundry.
7. 
Among the given species the resonance stabilised carbocations are:
(1) (III) and (IV) only
(2) (I), (II) and (III) only
(3) (I), (II) and (IV) only
(4) (I) and (II) only
8. The metal that can be purified economically by fractional distillation method is:
(1) Ni
(2) Cu
(3) Zn
(4) Fe
9. 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:
(1) (B) and (E) only
(2) (C) and (D) only
(3) (A) and (E) only
(4) (A) and (D) only
10. 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.
(1) Both A and R are correct but R is not the correct explanation of A.
(2) A is correct but R is not correct.
(3) Both A and R are correct and R is the correct explanation of A.
(4) A is not correct but R is correct.
11. Orlon fibres are made up of:
(1) Polyacrylonitrile
(2) Cellulose
(3) Polyamide
(4) Polyesters
12. In the given reaction,
C2H-OH 2-Bromo-3, 3-dimethyl butane 
Product A is :
(1) 2-Hydroxy-3, 3-dimethyl butane.
(2) 2-Ethoxy-2, 3-dimethyl butane.
(3) 2-Ethoxy-3, 3-dimethyl butane.
(4) 1-Ethoxy-3, 3-dimethyl butane
13. The correct order of intensity of colors of the compounds is :
(1) [Ni(CN)₄]2- > [Nicl₄)]2- > [Ni(H₂O)₆]2+
(2) [NiCl₄)]2- > [Ni(CN)₄]2- > [Ni(H₂O)₆]2+
(3) [NiCl₄)]2- > [Ni(H₂O)₆]2+ >[Ni(CN)₄)]2-
(4) [Ni(H₂O)]2+ > [Nicl₄)]2- > [Ni(CN)₄)]2-
14. An inorganic compound ‘X’ on treatment with concentrated H₂SO₄ produces brown fumes and gives dark brown ring with FeSO₄ in presence of concentrated H₂SO₄. Also compound ‘X’ gives precipitate ‘Y’, when its solution in dilute HCl is treated with H₂S gas. The precipitate ‘Y’ on treatment with concentrated HNO₃ followed by excess of NH₄OH further gives deep blue coloured solution, compound ‘X’ is :
(1) Cu(NO₃)₂
(2) Pb(NO₃)₂
(3) Pb(NO₂)₂
(4) CO(NO₃)₂
15. Identify the incorrect statement from the following:
(1) Glycogen is called as animal starch.
(2) β-Glycosidic linkage makes cellulose polymer.
(3) Amylose is a branched chain polymer of glucose.
(4) Starch is a polymer of α-D-glucose.
16. The correct structure of Ruhemann’s Purple, the compound formed in the reaction of ninhydrin with proteins is :
17. 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.
(1) Both A and R are true and R is the correct explanation of A.
(2) A is true but R is false.
(3) A is false but R is true.
(4) Both A and R are true but R is NOT the correct explanation of A.
18. Chemical nature of the nitrogen oxide compound obtained from a reaction of concentrated nitric acid and P₄O₁₀ (in 4:1 ratio) is:
(1) acidic
(2) amphoteric
(3) neutral
(4) basic
19. 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 :
(1) Na
(2) K
(3) Ca
(4) Mg
20. The species given below that does NOT show disproportionation reaction is :
(1) BrO–2
(2) BrO–₄
(3) Bro–
(4) BrO–₃
| Section B |
21. The number of lone pairs of electrons on the central I atom in l–₃ is_____.
22. An average person needs about 10000 kJ energy per day. The amount of glucose (molar mass = 180.0 g mol–¹) needed to meet this energy requirement is ____g.
(Nearest integer)
(Use : ΔCH(glucose) = -2700 kJ mol–¹)
23. To synthesise 1.0 mole of 2-methylpropan-2mol fromEthylethanoate_____ equivalents of CH₃MgBr reagent will be required. (Integer value)
24. The Azimuthal quantum number for the valence electrons of Ga+ ion is____
(Atomic number of Ga =31)
25. At 20°C, the vapour pressure of benzene is 70 torr and that of methyl benzene is 20 torr. The mole fraction of benzene in the vapour phase at 20°C above an equimolar mixture of benzene and methyl benzene is_____x
10–²(Nearest integer)
26. 250 mL of 0.5 M NaOH was added to 500 mL of 1 M HCl. The number of unreacted HCl molecules in the solution after complete reaction is _____ x 10²¹. (Nearest integer)
(NA= 6.022 x 10²³)
27. The number of nitrogen atoms in a semicarbazone molecule of acetone is_____
28. The spin-only magnetic moment value for the complex [Co(CN₆)]⁴– is________ BM
[At. no. of Co = 27]
29. 2SO₂(g) + O₂(g) ⇌ 2SO₃(g)
In an equilibrium mixture, the partial pressures are
PSO₂ = 43 kPa; Po₂ = 530 Pa and
PSO₂ = 45 kPa The equilibrium constant
KP =____ x 10–². (Nearest integer)
30. The inactivation rate of a viral preparation is proportional to the amount of virus. In the first minute after preparation, 10% of the virus is inactivated. The rate constant for viral inactivation is______ x 10–³ min–¹ (Nearest integer)
[Use : In 10 = 2.303; log₁₀3 = 0.477; property of logarithm : log xy = y log x].
JEE Main Solved Paper Question Answer With Solutions
JEE Main 2021 Paper with Solutions
| ⚫ | JEE Main 2021 Paper with Solutions – 20th July – Shift 1 |
| 1. | JEE Main Physics Question Paper |
| 2. | JEE Main Chemistry Question Paper |
| 3. | JEE Main Maths Question Paper |
