Practice Questions
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Q34.Consider the species CH4, NH+4 and BH−4 . Choose the correct option with respect to the there species: (1) They are isoelectronic and only two have (2) They are isoelectronic and all have tetrahedral tetrahedral structures structures (3) Only two are isoelectronic and all have (4) Only two are isoelectronic and only two have tetrahedral structures tetrahedral structures
Q34.The formula of the purple colour formed in Laissaigne's test for sulphur using sodium nitroprusside is (1) Na4[Fe (CN)5(NOS)] (2) NaFe[Fe (CN)6] (3) Na[Cr (NH3)2(NCS)4] (4) Na2[Fe (CN)5(NO)]
Q34.In base vs. Acid titration, at the end point methyl orange is present as (1) quinonoid form (2) heterocyclic form (3) phenolic form (4) benzenoid form
Q34.Which one of the following alkaline earth metal ions has the highest ionic mobility in its aqueous solution? (1) Sr2 + (2) Mg2 + (3) Ca2 + (4) Be2 +
Q34.Given below are two statements: One is labelled as Assertion A and the other is labelled as Reason R Assertion A : The reduction of a metal oxide is easier if the metal formed is in liquid state than solid state. Reason R : The value of ΔGΘ becomes more on negative side as entropy is higher in liquid state than solid state. In the light of the above statements. Choose the most appropriate answer from the options given below (1) Both A and R are correct and R is the correct (2) Both A and R are correct but R is NOT the explanation of A correct explanation of A (3) A is correct but R is not correct (4) A is not correct but R is correct
Q34.The Ksp for bismuth sulphide Bi2S3 is 1 . 08 × 10-73. The solubility of Bi2S3 in molL-1 at 298 K is (1) 1 . 0 × 10-15 (2) 2 . 7 × 10-12 (3) 3 . 2 × 10-10 (4) 4 . 2 × 10-8
Q34.The Plot of pH -metric titration of weak base NH4 OH vs strong acid HCl looks like (1) (2) (3) (4)
Q34.In the structure of SF4 , the lone pair of electrons on S is in. (1) Equatorial position and there are two lone pair - (2) equatorial position and there are three lone pair - bond pair repulsions at 90° . bond pair repulsions at 90° . (3) axial position and there are three lone pair - bond (4) axial position and there are two lone pair - bond pair repulsion at 90° . pair repulsion at 90° .
Q34.Number of lone pairs of electrons in the central atom of SCl2, O3, ClF3 and SF6 , respectively, are (1) 0, 1, 2 & 2 (2) 2, 1, 2 & 0 (3) 1, 2, 2 & 0 (4) None of these
Q34.The metal salts formed during softening of hardwater using Clark's method are (1) CaOH2 and MgOH2 (2) CaCO3 and MgOH2 (3) CaOH2 and MgCO3 (4) CaCO3 and MgCO3
Q35.A compound 'X' is a weak acid and it exhibits colour change at pH close to the equivalence point during neutralization of NaOH with CH3COOH. Compound 'X' exists in ionized form in basic medium. The compound 'X' is JEE Main 2022 (29 Jul Shift 2) JEE Main Previous Year Paper (1) methyl orange (2) methyl red (3) phenolphthalein (4) erichrome Black T
Q35.At 25 °C and 1 atm pressure, the enthalpies of combustion are as given below: Substance H2 C (graphite) C2H6(g) ΔcHΘ −286. 0 −394. 0 −1560. 0 kJmol−1 The enthalpy of formation of ethane is JEE Main 2022 (24 Jun Shift 2) JEE Main Previous Year Paper (1) +54. 0 kJ mol−1 (2) −68. 0 kJ mol−1 (3) −86. 0 kJ mol−1 (4) +97. 0 kJ mol−1
Q35.An element A of group 1 shows similarity to an element B belonging to group 2 . If A has maximum hydration enthalpy in group 1 then B is (1) Mg (2) Be (3) Ca (4) Sr
Q35.The correct order of melting point is (1) Sr > Ca > Mg > Be (2) Be > Mg > Ca > Sr (3) Be > Ca > Sr > Mg (4) Be > Ca > Mg > Sr
Q35.Which of the following is most stable ? JEE Main 2022 (27 Jun Shift 2) JEE Main Previous Year Paper (1) (2) (3) (4)
Q35.Given below are two statements. One is labelled as Assertion A and the other is labelled as Reason R. Assertion A : Activated charcoal adsorbs SO2 more efficiently than CH4 . Reason R : Gases with lower critical temperatures are readily adsorbed by activated charcoal. 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) Both A and R are correct but R is NOT the explanation of A . correct explanation of A . (3) A is correct but R is not correct. (4) A is not correct but R is correct.
Q35.Assertion: The amphoteric behaviour of water is explained by Lewis acid base theory Reason: water acts as acid with NH3 and base with H2S (1) Both Assertion and Reason are true and Reason is (2) Both Assertion and Reason are true but Reason is the correct explanation of Assertion. NOT the correct explanation of Assertion. (3) Assertion is true but Reason is false. (4) Assertion is false but Reason is true.
Q35.Reaction of BeCl2 with LiAlH4 gives : (A) AlCl3 (B) BeH2 (C) LiH (D) LiCl (E) BeAlH4 Choose the correct answer from options given below (1) (A), (D) & (E) (2) (A), (B) & (D) (3) (D) & (E) (4) (B), (C) & (D)
Q35.Phenol on reaction with dilute nitric acid, gives two products. Which method will be most efficient for large scale separation? (1) Chromatographic separation (2) Steam distillation (3) Fractional Crystallisation (4) Sublimation
Q35.Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R. Assertion A :Phenolphthalein is a pH dependent indicator, remains colourless in acidic solution and gives pink colour in basic medium Reason R : Phenolphthalein is a weak acid. It doesn't dissociate in basic medium. In the light of the above statements, choose the most appropriate answer from the options given below (1) Both A and R are true and R is the correct (2) Both A and R are true but R is NOT the correct explanation of A explanation of A. (3) A is true but R is false (4) A is false but R is true
Q35.High purity (> 99. 95%) dihydrogen is obtained by (1) reaction of zinc with aqueous alkali. (2) electrolysis of warm aqueous barium hydroxide solution between nickel electrodes. (3) electrolysis of acidified water using platinum (4) reaction of zinc with dilute acid. electrodes.
Q35.Given below are two statements: One is labelled as Assertion A and the other is labelled as Reason R Assertion A : Permanganate titration are not performed in presence of hydrochloric acid. Reason R : Chlorine is formed as a consequence of oxidation of hydrochloric acid. In the light of the above statements, choose the correct answer from the options given below (1) Both A and R are true and R is the correct (2) Both A and R are true but R is NOT the correct explanation of A explanation of A (3) A is true but R is false (4) A is false but R is true
Q35. BeCl2 reacts with LiAlH4 to give (1) Be + Li[AlCl4] + H2 (2) Be + AlH3 + LiCl + HCl (3) BeH2 + LiCl + AlCl3 (4) BeH2 + Li[AlCl4]
Q35.Which of the following statements are correct ? (A) Both LiCl and MgCl2 are soluble in ethanol. JEE Main 2022 (24 Jun Shift 1) JEE Main Previous Year Paper (B) The oxides Li2 O and MgO combine with excess of oxygen to give superoxide. (C) LiF is less soluble in water than other alkali metal fluorides. (D) Li2 O is more soluble in water than other alkali metal oxides. Choose the most appropriate answer from the options given below (1) (A) and (C) only (2) (A), (C) and (D) only (3) (B) and (C) only (4) (A) and (D) only
Q35.A student needs to prepare a buffer solution of propanoic acid and its sodium salt with pH 4. The ratio of [CH3 CH2 COO−] required to make buffer is Given : Ka(CH3 CH2 COOH) = 1. 3 × 10−5 [CH3 CH2 COOH] (1) 0. 03 (2) 0. 13 (3) 0. 23 (4) 0. 33