Practice Questions

Q40.The measured BOD values tor four difterent water samples (A −D) are as tollows: A = 3 ppm; B = 18 ppm; C = 21 ppm; D = 4 ppm. The water samples which can be called as highly polluted with organic wastes, are (1) A&B (2) A&D (3) B&C (4) B&D

Q40.Match List I with List II List-I List-II Pollutant Source A Microorganisms I Strip mining B Plant nutrients II Domestic sewage C Toxic heavy metals III Chemical fertilizer D Sediment IV Chemical factory Choose the correct answer from the options given below (1) A - II, B - III, C - IV, D - I (2) A - II, B - I, C - IV, D - III (3) A - I, B - IV, C - II, D - III (4) A - I, B - IV, C - III, D - II

Q40.Given below are two statements. Statement I : The compound is optically active. Statement II : ​ is mirror image of above compound A. In the light of the above statement, choose the most appropriate answer from the options given below. JEE Main 2022 (29 Jul Shift 2) JEE Main Previous Year Paper (1) Both Statement I and Statement II are correct (2) Both Statement I and Statement II are incorrect. (3) Statement I is correct but Statement II is (4) Statement I is incorrect but Statement II is incorrect. correct.

Q40.The acid that is believed to be mainly responsible for the damage of Taj Mahal is (1) sulfuric acid. (2) hydrofluoric acid. (3) phosphoric acid. (4) hydrochloric acid.

Q40.Match List - I with List - II : List-I List-II (A) Sphalerite (I) FeCO3 (B) Calamine (II) PbS (C) Galena (III) ZnCO3 (D) Siderite (IV) ZnS Choose the most appropriate answer from the options given below : (1) (A) −(IV), (B) −(I), (C) −(II), (D) −(III) (2) (A) −(IV), (B) −(III), (C) −(II), (D) −(I) (3) (A) −(II), (B) −(II), (C) −(I), (D) −(IV) (4) (A) −(III), (B) −(IV), (C) −(II), (D) −(I)

Q41.Dihydrogen reacts with CuO to give (1) Cu (OH)2 (2) Cu(s) (3) Cu2 O (4) CuH2

Q41.The major product formed in the given reaction is: JEE Main 2022 (26 Jul Shift 1) JEE Main Previous Year Paper (1) (2) (3) (4)

Q41.The role of depressants in 'Froth Floation method' is to JEE Main 2022 (26 Jun Shift 2) JEE Main Previous Year Paper (1) selectively prevent one component of the ore (2) reduce the consumption of oil for froth from coming to the froth. formation. (3) stabilize the froth. (4) enhance non-wettability of the mineral particles.

Q41.In following pairs, the one in which both transition metal ions are colourless is (1) Sc3+, Zn2+ (2) Ti4+, Cu2+ (3) V2+, Ti3+ (4) Zn2+, Mn2+

Q41.In the metallurgical extraction of copper, following reaction is used : FeO + SiO2 →FeSiO3 FeO and FeSiO3 respectively are. (1) gangue and flux. (2) flux and slag (3) slag and flux. (4) Gauge and slag

Q41.The depression in freezing point observed for a formic acid solution of concentration 0 . 5 mL L-1 is 0 . 0405 °C. Density of formic acid is 1 . 05 g mL-1. The Van't Hoff factor of the formic acid solution is nearly: (Given for water kf = 1 . 86 K kg mol-1) (1) 0 . 8 (2) 1 . 1 (3) 1 . 9 (4) 2 . 4

Q42.The most stable trihalide of nitrogen is. (1) NF3 (2) NCl3 (3) NBr3 (4) NI3

Q42.Which of the following methods are not used to refine any metal? (A) Liquation (B) Calcination (C) Electrolysis (D) Leaching (E) Distillation Choose the correct answer from the options given below (1) B and D only (2) A, B, D and E only (3) B, D and E only (4) A, C and E only

Q42.Match List I with List II. List I With Ore List II Composition A.Siderite I. FeCO3 B.Malachite II. CuCO3 ⋅Cu(OH)2 C.Sphalerite III. ZnS D.Calamine IV. ZnCO3 Choose the correct answer from the options given below: (1) A-I, B-II, C-III, D-IV (2) A-III, B-IV, C-E, D-I (3) A-IV, B-III, C-I, D-II (4) A-I, B-II, C-IV, D-III

Q42.In liquation process used for tin Sn, the metal (1) is reacted with acid (2) is dissolved in water (3) is brought to molten form which is made to flow (4) is fused with NaOH, on a slope

Q42.The most common oxidation state of Lanthanoid elements is +3. Which of the following is likely to deviate easily from +3 oxidation state? (1) Ce(At. No, 58) (2) La(At. No, 57) (3) Lu(At. No, 71) (4) Gd(At. No, 64)

Q42.The compound(s) that is(are) removed as slag during the extraction of copper is : (1) CaO (2) FeO (3) Al2O3 (4) ZnO (5) NiO Choose the correct answer from the options given below (1) 3, 4 only (2) 2 only (3) 1, 2, 5 Only (4) 1, 2 only

Q43.Which one of the following elemental forms is not present in the enamel of the teeth? (1) Ca2+ (2) P3+ (3) F− (4) P5+

Q43.Given below are two statements. Statement I : Pig iron is obtained by heating cast iron with scrap iron. Statement II : Pig iron has a relatively lower carbon content than that of cast iron. In the light of the above statements, choose the correct answer from the options given below. (1) Both Statement I and Statement II are correct. (2) Both Statement I and Statement II are not correct. (3) Statement I is correct but Statement II is not (4) Statement I is not correct but Statement II is correct correct.

Q43.The metal that is not extracted from its sulphide ore is (1) Aluminium (2) Iron (3) Lead (4) Zinc

Q43.Dinitrogen is a robust compound, but reacts at hig altitude to form oxides. The oxide of nitrogen the can damage plant leaves and retard photosynthes is (1) NO (2) NO3- (3) NO2 (4) NO2-

Q43.The interhalogen compound formed from the reaction of bromine with excess of fluorine is a (1) hypohalite (2) halate (3) perhalate (4) halite

Q43.Polar stratospheric clouds facilitate the formation of (1) ClONO2 (2) HOCl (3) ClO (4) CH4

Q43.Which of the reaction is suitable for concentrating ore by leaching process? (1) 2Cu2 S + 3O2 →2Cu2O + 2SO2 (2) Fe3O4 + CO →3FeO + CO2 (3) Al2O3 + 2NaOH + 3H2O →2NaAlOH4 (4) Al2O3 + 6Mg →6MgO + 4Al

Q43.Refining using liquation method is the most suitable for metals with (1) Low melting point (2) High boiling point (3) High electrical conductivity (4) Less tendency to be soluble in melts than impurities