Practice Questions

Q38.Which hydride among the following is less stable? (1) BeH2 (2) HF (3) NH3 (4) LiH

Q38.Which of the following reaction is correct? (1) Δ (2) Δ 2 LiNO3 →2 LiNO2 + O2 4 LiNO3 →2 Li2 O + 2N2O4 + O2 (3) Δ (4) Δ 4 LiNO3 →2 Li2 O + 4 NO2 + O2 2 LiNO3 →2Li + 2 NO2 + O2

Q38.In the depression of freezing point experiment A. Vapour pressure of the solution is less than that of pure solvent B. Vapour pressure of the solution is more than that of pure solvent C. Only solute molecules solidify at the freezing point D. Only solvent molecules solidify at the freezing point (1) A and D only (2) B and C only (3) A and C only (4) A only

Q38.The titration curve of weak acid vs. strong base with phenolphthalein as indicator is shown below. The Kphenolphthalein = 4 × 10−10 Given: log 2 = 0. 3 The number of following statement/s which is/are correct about phenolphthalein is _______ A. It can be used as an indicator for the titration of weak acid with weak base. B. It begins to change colour at pH = 8. 4 C. It is a weak organic base D. It is colourless in acidic medium Q39. 2 IO−3 + xI−+ 12H+ →6I2 + 6H2 What is the value of x ? (1) 2 (2) 12 (3) 10 (4) 6

Q38.Thin layer chromatography of a mixture shows the following observation: The correct order of elution in the silica gel column chromatography is (1) B, A, C (2) B, C, A (3) A, C, B (4) C, A, B

Q38.Decreasing order of reactivity towards electrophilic substitution for the following compounds is: (1) d > a > e > c > b (2) e > d > a > b > c (3) a > d > e > b > c (4) c > b > a > d > e

Q38.Using column chromatography, mixture of two compounds ‘A’ and ‘B’ was separated. ‘A’ eluted first, this indicates ‘B’ has (1) low Rf, stronger adsorption (2) high Rf, weaker adsorption (3) high Rf, stronger adsorption (4) low Rf, weaker adsorption

Q38.Given below are two statements, one is labelled as Assertion A and the other is labelled as Reason R. Assertion A : Order of acidic nature of the following compounds is A > B > C. Reason R: Fluoro is a stronger electron withdrawing group than Chloro group. In the light of the above statements, choose the correct answer from the options given below : (1) A is false but R is true (2) Both A and R are correct and R is the correct explanation of A (3) A is true but R is false (4) Both A and R are correct but R is NOT the correct explanation of A

Q38.Given below are two statements: One is labelled as Assertion A and the other is labelled as Reason R. Assertion A: Amongst He, Ne, Ar and Kr; 1 g of activated charcoal adsorbs more of Kr. Reason R: The critical volume Vc (cm3 mol – 1 ) and critical pressure Pc (atm) is highest for Krypton but the compressibility factor at critical point Zc is lowest for Krypton. In the light of the above statements, choose the correct answer from the options given below. (1) A is true but R is false (2) A is false but R is true (3) Both A and R are true but R is NOT the correct (4) Both A and R are true and R is the correct explanation of A explanation A

Q38.Given below are two statements: Statement-I : Methyl orange is a weak acid. Statement-II : The benzenoid form of methyl orange is more intense/deeply coloured than the quinonoid form. In the light of the above statement, choose the most appropriate answer from the options given below: (1) Both Statement-I and Statement-II are incorrect(2) Statement-I is incorrect but Statement-II is correct (3) Both Statement-I and Statement-II are correct (4) Statement-I is correct but Statement-II is incorrect

Q38.During the reaction of permanganate with thiosulphate, the change in oxidation of manganese occurs by value of 3. Identify which of the below medium will favour the reaction. (1) Both aqueous acidic and neutral (2) Aqueous neutral (3) Both aqueous acidic and faintly alkaline (4) Aqueous acidic

Q39.Given below are two statements : Statement I : Tropolone is an aromatic compound and has 8𝜋 electrons. Statement II : 𝜋 electrons of > C = O group in tropolone is involved in aromaticity. In the light of the above statements choose the correct answer from the options given below: (1) Statement I is true but Statement II is false (2) Statement I is false but Statement II is true (3) Both Statement I and Statement II are false (4) Both Statement I and Statement II are true

Q39.Which of the following represents the correct order of metallic character of the given elements? (1) Si < Be < Mg < K (2) Be < Si < Mg < K (3) K < Mg < Be < Si (4) Be < Si < K < Mg

Q39.Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): Gypsum is used for making fireproof wall boards. Reason (R): Gypsum is unstable at high temperatures. In the light of the above statements, choose the correct answer from the options given below: (1) Both (A) and (R) are correct but (R) is not the (2) (A) is correct but (R) is not correct. correct explanation of (A). (3) (A) is not correct but (R) is correct. (4) Both (A) and (R) are correct and (R) is the correct explanation of (A).

Q39.The compound which will have the lowest rate towards nucleophilic aromatic substitution on treatment with OH– is JEE Main 2023 (25 Jan Shift 1) JEE Main Previous Year Paper (1) (2) (3) (4)

Q39.The methods NOT involved in concentration of ore are (A) Liquation (B) Leaching (C) Electrolysis (D) Hydraulic washing (E) Froth floatation Choose the correct answer from the options given below: (1) B, D and C only (2) C, D and E only (3) A and C only (4) B, D and E only

Q39.Given below are two statements : Statement I : H2O2 is used in the synthesis of Cephalosporin Statement II : H2O2 is used for the restoration of aerobic conditions to sewage wastes. In the light of the above statements, choose the most appropriate answer from the options given below : (1) Statement I is correct but Statement II is (2) Both Statement I and Statement II are correct incorrect (3) Statement I is incorrect but Statement II is (4) Both Statement I and Statement II are incorrect correct

Q39.Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason 𝑅 Assertion A: In an Ellingham diagram, the oxidation of carbon to carbon monoxide shows a negative slope with respect to temperature. Reason R: CO tends to get decomposed at higher temperature. In the light of the above statements, choose the correct answer from the options given below (1) Both A and R are correct and R is the correct (2) A is not correct but R is correct explanation of A (3) (3) Both A and R are correct but R is NOT the (4) A is correct but R is not correct correct explanation of A

Q39.Identify the correct statements about alkali metals. A. The order of standard reduction potential (M+ | M) for alkali metal ions is Na > Rb > Li. B. CsI is highly soluble in water. C. Lithium carbonate is highly stable to heat. D. Potassium dissolved in concentrated liquid ammonia is blue and paramagnetic. E. All alkali metal hydrides are ionic solids. Choose the correct answer from the options given below (1) A, B, D only (2) C and E only (3) A and E only (4) A, B and E only

Q39.Match List I with List II List I List II Type of Hydride Example A Electron deficient hydride I MgH2 B Electron rich hydride II HF C Electron precise hydride III B2H6 D Saline hydride IV CH4 Choose the correct answer from the options given below : (1) A-III, B-II, C-IV, D-I (2) A-II, B-III, C-I, D-IV (3) A-II, B-III, C-IV, D-I (4) A-III, B-II, C-I, D-IV

Q39.Given below are two statements: Statement I : Nickel is being used as the catalyst for producing syn gas and edible fats. Statement II : Silicon forms both electron rich and electron deficient hydrides. In the light of the above statements, choose the most appropriate answer from the options given below: (1) Both the statements I and II are correct (2) Statement I is incorrect but statement II is correct (3) Both the statements I and II are incorrect (4) Statement I is correct but statement II is incorrect

Q39.Boric acid in solid, whereas BF3 is gas at room temperature because of (1) Strong ionic bond in Boric acid (2) Strong van der Waal's interaction in Boric acid (3) Strong hydrogen bond in Boric acid (4) Strong covalent bond in BF3

Q39.Alkali metal from the following with least melting point is (1) Cs (2) Rb (3) Na (4) K

Q39.The solubility product of BaSO4 is 1 × 10−10 at 298 K. The solubility of BaSO4 in 0. 1M K2 SO4(aq) solution is ------ ×10−9 g L−1 (nearest integer). Given: Molar mass of BaSO4 is 233 g mol−1

Q39.The magnetic behaviour of Li2 O, Na2 O2 and KO2 , respectively, are (1) diamagnetic, paramagnetic and diamagnetic (2) paramagnetic, paramagnetic and diamagnetic (3) paramagnetic, diamagnetic and paramagnetic (4) diamagnetic, diamagnetic and paramagnetic