Hydrogen & s-Block · JEE Main previous year questions

114 questions asked across 17 exam years, newest first

Year-wise papers Topic-wise questions

Practise this topic

2022 19 questions

Q782022 · 29 Jul 2022 · Shift 1
Lithium nitrate and sodium nitrate, when heated separately, respectively, give :
1. A. $LiN O_{2}$ and $NaN O_{2}$
2. B. $L i_{2} O$ and $N a_{2} O$
3. C. $L i_{2} O$ and $NaN O_{2}$
4. D. $LiN O_{2}$ and $N a_{2} O$
Show answer
Answer: C
Q652022 · 29 Jul 2022 · Shift 2
Given below are two statements. Statement I : Stannane is an example of a molecular hydride. Statement II : Stannane is a planar molecule. In the light of the above statement, choose the most appropriate answer from the options given below.
1. A.Both Statement I and Statement II are true.
2. B.Both Statement I and Statement II are false.
3. C.Statement I is true but Statement II is false.
4. D.Statement I is false but Statement II is true.
Show answer
Answer: C
Q772022 · 29 Jul 2022 · Shift 2
Portland cement contains 'X' to enhance the setting time. What is 'X'?
1. A. $CaS O_{4} \cdot \frac{1}{2} H_{2} O$
2. B. $CaS O_{4} \cdot 2 H_{2} O$
3. C. $CaS O_{4}$
4. D. $CaC O_{3}$
Show answer
Answer: B
Q732022 · 28 Jul 2022 · Shift 1
For kinetic study of the reaction of iodide ion with $H_{2} O_{2}$ at room temperature : (A) Always use freshly prepared starch solution. (B) Always keep the concentration of sodium thiosulphate solution less than that of $KI$ solution. (C) Record the time immediately after the appearance of blue colour. (D) Record the time immediately before the appearance of blue colour. (E) Always keep the concentration of sodium thiosulphate solution more than that of $KI$ solution. Choose the correct answer from the options given below :
1. A.(A), (B), (C) only
2. B.(A), (D), (E) only
3. C.(D), (E) only
4. D.(A), (B), (E) only
Show answer
Answer: A
Q752022 · 28 Jul 2022 · Shift 2
The products obtained during treatment of hard water using Clark's method are :
1. A. $CaC O_{3}$ and $MgC O_{3}$
2. B. $Ca (OH)_{2}$ and $Mg (OH)_{2}$
3. C. $CaC O_{3}$ and $Mg (OH)_{2}$
4. D. $Ca (OH)_{2}$ and $MgC O_{3}$
Show answer
Answer: C
Q762022 · 28 Jul 2022 · Shift 2
Statement I : An alloy of lithium and magnesium is used to make aircraft plates. Statement II : The magnesium ions are important for cell-membrane integrity. In the light the above statements, choose the correct answer from the options given below :
1. A.Both Statement I and Statement II are true
2. B.Both Statement I and Statement II are false
3. C.Statement I is true but Statement II is false
4. D.Statement I is false but Statement II is true
Show answer
Answer: B
Q782022 · 27 Jul 2022 · Shift 2
Given below are two statements: Statement I : The non bio-degradable fly ash and slag from steel industry can be used by cement industry. Statement II : The fuel obtained from plastic waste is lead free. In the light of the above statements, choose the most appropriate answer from the options given below :
1. A.Both Statement I and Statement II are correct
2. B.Both Statement I and Statement II are incorrect
3. C.Statement I is correct but Statement II is incorrect
4. D.Statement I is incorrect but Statement II is correct
Show answer
Answer: A
Q902022 · 27 Jul 2022 · Shift 2· Numerical answer
The oxidation state of manganese in the product obtained in a reaction of potassium permanganate and hydrogen peroxide in basic medium is ____________.
Show answer
Answer: 4
Q672022 · 25 Jul 2022 · Shift 2
Match List I with List II: | List I | List II | | :--- | :--- | | (A) Sulphate | (I) Pesticide | | (B) Fluoride | (II) Bending of bones | | (C) Nicotine | (III) Laxative effect | | (D) Sodium arsenite | (IV) Herbicide | Choose the correct answer from the options given below :
1. A.A-II, B-III, C-IV, D-I
2. B.A-IV, B-III, C-II, D-I
3. C.A-III, B-II, C-I, D-IV
4. D.A-III, B-II, C-IV, D-I
Show answer
Answer: C
Q872022 · 25 Jul 2022 · Shift 2· Numerical answer
A sample of 4.5 mg of an unknown monohydric alcohol, R-OH was added to methylmagnesium iodide. A gas is evolved and is collected and its volume measured to be 3.1 mL. The molecular weight of the unknown alcohol is __________ g/mol. [Nearest integer]
Show answer
Answer: 33
Q762022 · 30 Jun 2022 · Shift 1
Match List - I with List - II : | List-I | List-II | | :--- | :--- | | (a) Sodium hydride | (i) Lewis acid | | (b) Silane | (ii) Saline hydride | | (c) Vanadium hydride | (iii) Molecular hydride | | (d) Aluminium hydride | (iv) Non-stoichiometric hydride | Correct answer is :
1. A.(a)-(ii), (b)-(iii), (c)-(iv), (d)-(i)
2. B.(a)-(ii), (b)-(iv), (c)-(iii), (d)-(i)
3. C.(a)-(iii), (b)-(ii), (c)-(i), (d)-(iv)
4. D.(a)-(i), (b)-(iii), (c)-(iv), (d)-(ii)
Show answer
Answer: A
Q772022 · 30 Jun 2022 · Shift 1
Correct statement about alkali metal oxides is :
1. A.peroxides are colored.
2. B.superoxides are paramagnetic.
3. C.oxides are paramagnetic.
4. D.peroxides are both colored and paramagnetic.
Show answer
Answer: B
Q742022 · 27 Jun 2022 · Shift 2
Match List I with List II. | | List-I (Anion) | | List-II (gas evolved on reaction with dil. $H_{2} SO_{4}$ ) | |---|---|---|---| | (A) | $CO_{3}^{2 -}$ | I. | Colourless gas which turns lead acetate paper black. | | (B) | $S^{2 -}$ | II. | Colourless gas which turns acidified potassium dichromate solution green. | | (C) | $SO_{3}^{2 -}$ | III. | Brown fumes which turns acidified KI solution containing starch blue. | | (D) | $NO_{2}^{-}$ | IV. | Colourless gas evolved with brisk effervescence, which turns lime water milky. | Choose the correct answer from the options given below :
1. A.A-III, B-I, C-II, D-IV
2. B.A-II, B-I, C-IV, D-III
3. C.A-IV, B-I, C-III, D-II
4. D.A-IV, B-I, C-II, D-III
Show answer
Answer: D
Q762022 · 27 Jun 2022 · Shift 2
Statement I : Leaching of gold with cyanide ion in absence of air / $O_{2}$ leads to cyano complex of Au(III). Statement II : Zinc is oxidized during the displacement reaction carried out for gold extraction. In the light of the above statements, choose the correct answer from the options given below.
1. A.Both Statement I and Statement II are correct.
2. B.Both Statement I and Statement II are incorrect.
3. C.Statement I is correct but Statement II is incorrect.
4. D.Statement I is incorrect but Statement II is correct.
Show answer
Answer: D
Q772022 · 27 Jun 2022 · Shift 2
The gas produced by treating an aqueous solution of ammonium chloride with sodium nitrite is :
1. A. $NH_{3}$
2. B. $N_{2}$
3. C. $N_{2} O$
4. D. $Cl_{2}$
Show answer
Answer: B
Q772022 · 26 Jun 2022 · Shift 2
Boiling of hard water is helpful in removing the temporary hardness by converting calcium hydrogen carbonate and magnesium hydrogen carbonate to :
1. A. $CaC O_{3}$ and $Mg (OH)_{2}$
2. B. $CaC O_{3}$ and $MgC O_{3}$
3. C. $Ca (OH)_{2}$ and $MgC O_{3}$
4. D. $Ca (OH)_{2}$ and $Mg (OH)_{2}$
Show answer
Answer: A
Q822022 · 25 Jun 2022 · Shift 1· Numerical answer
The longest wavelength of light that can be used for the ionisation of lithium atom ( $Li$ ) in its ground state is $x \times 1 0^{- 8} m$ . The value of $x$ is . (Nearest Integer). (Given : Energy of the electron in the first shell of the hydrogen atom is $- 2.2 \times 1 0^{- 18} J$ ; $h = 6.63 \times 1 0^{- 34} Js$ and $c = 3 \times 1 0^{8} ms^{- 1}$ )
Show answer
Answer: 4
Q702022 · 25 Jun 2022 · Shift 2
During halogen test, sodium fusion extract is boiled with concentrated $HN O_{3}$ to
1. A.remove unreacted sodium
2. B.decompose cyanide or sulphide of sodium
3. C.extract halogen from organic compound
4. D.maintain the pH of extract.
Show answer
Answer: B
Q722022 · 24 Jun 2022 · Shift 2
Hex-4-ene-2-ol on treatment with PCC gives 'A'. 'A' on reaction with sodium hypoiodite gives 'B', which on further heating with soda lime gives 'C'. The compound 'C' is :
1. A.2-pentene
2. B.proponaldehyde
3. C.2-butene
4. D.4-methylpent-2-ene
Show answer
Answer: C