Practice Questions

Q40.Diborane B2H6 reacts independently with O2 and H2O to produce, respectively: - (1) HBO2 and H3BO3 (2) H3BO3 and B2O3 (3) B2O3 and [BH4] (4) B2O3 and H3BO3

Q40.The electronegativity of aluminum is similar to: (1) Beryllium (2) Boron (3) Carbon (4) Lithium

Q40.The layer of atmosphere between 10 km to 50 km above the sea level is called as: (1) stratosphere (2) troposphere (3) mesosphere (4) thermosphere

Q40.Which of the following conditions in drinking water causes methemoglobinemia? (1) > 50 ppm of nitrate (2) > 50 ppm of chloride (3) > 100 ppm of sulphate (4) > 50 ppm of lead

Q40.The correct order of catenation is: (1) Ge > Sn > Si > C (2) C > Sn > Si ≈Ge (3) C > Si > Ge ≈Sn (4) Si > Sn > C > Ge

Q40.The number of pentagons in C60 and trigons (triangles) in white phosphorus, are; (1) 12 and 3 (2) 20 and 4 (3) 20 and 3 (4) 12 and 4

Q40.The volume strength of 1M H2O2 is: (Molar mass of H2O2 = 34 g mol−1 ) (1) 5.6 (2) 22.4 (3) 11.2 (4) 16.8

Q40.Correct statements among regarding silicones are: ( 𝑎) They are polymers with hydrophobic character. ( 𝑏) They are biocompatible. ( 𝑐) In general, they have high thermal stability and low dielectric strength. ( 𝑑) Usually, they are resistant to oxidation and used as greases. (1) ( 𝑎) , ( 𝑏) and ( 𝑐) only (2) ( 𝑎) and ( 𝑏) only (3) ( 𝑎) , ( 𝑏) , ( 𝑐) and ( 𝑑) (4) ( 𝑎) , ( 𝑏) and ( 𝑑) only

Q41.The principle of column chromatography is: (1) Differential adsorption of the substances on the (2) Differential absorption of the substances on the solid phase. solid phase. (3) Gravitational force. (4) Capillary action

Q41.The basic structural unit of feldspar, zeolites mica, and asbestos is: (1) SiO4 4 - (2) (3) SiO3 2 - (4) SiO2 JEE Main 2019 (12 Apr Shift 1) JEE Main Previous Year Paper

Q42.The major product of the f following reaction is: JEE Main 2019 (08 Apr Shift 1) JEE Main Previous Year Paper (1) (2) (3) (4)

Q42.If Dichloromethane (DCM) and water H2O are used for differential extraction, which one of the following statements is correct? (1) DCM and H2O would stay as upper and lower (2) DCM and H2O will be miscible clearly layer respectively in the separating funnel (S.F.) (3) DCM and H2O would stay as lower and upper (4) DCM and H2O will make turbid/colloidal layer respectively in the S.F mixture JEE Main 2019 (10 Jan Shift 1) JEE Main Previous Year Paper

Q42.Taj Mahal is being slowly disfigured and discoloured. This is primarily due to (1) Global warming (2) Acid rain (3) Water pollution (4) Soil pollution

Q42.A solution of Ni(NO3)2 is electrolyzed between platinum electrode 0.1 Faraday electricity. How many mole of Ni will be deposited at the cathode? (1) 0.10 (2) 0.15 (3) 0.05 (4) 0.20

Q42.The amount of sugar (C12H22O11) required to prepare 2L of its 0 .1 M aqueous solution is: (1) 17 .1 g (2) 136 .8 g (3) 68 .4 g (4) 34 .2 g

Q43.The compound that is NOT a common component of photochemical smog is: (1) O3 (2) CF2Cl2 (3) (4) CH2 = CHCHO

Q43.Excessive release of CO2 into the atmosphere results in (1) global warming. (2) polar vortex. (3) depletion of ozone. (4) formation of smog.

Q43.The elevation in boiling point for 1 molal solution of glucose is 2 K. The depression in freezing point for 2 molal solution of glucose in the same solvent is 2 K. The relation between Kb and Kf is: (1) Kb = 2 Kf (2) Kb = 1 .5 Kf (3) Kb = Kf (4) Kb = 0 .5 Kf

Q43.The major product of the following reaction is: (1) (2) (3) (4)

Q43.Peroxyacetyl nitrate (PAN), an eye irritant, is produced by: (1) Classical smog (2) Acid rain (3) Organic waste (4) Photochemical smog

Q43.The regions of the atmosphere, where clouds form and where we live, respectively, are: (1) Troposphere and Troposphere (2) Stratosphere and Stratosphere (3) Stratosphere and Troposphere (4) Troposphere and Stratosphere

Q43.The maximum prescribed concentration of copper in drinking water is: JEE Main 2019 (08 Apr Shift 2) JEE Main Previous Year Paper (1) 3 ppm (2) 5 ppm (3) 0.5 ppm (4) 0.05 ppm

Q44.The concentration of dissolved oxygen (DO) in cold water can go upto (1) 14ppm (2) 8 ppm (3) 10ppm (4) 16pom

Q44.The primary pollutant that leads to photochemical smog is: (1) nitrogen oxides (2) ozone (3) acrolein (4) Sulphur dioxide

Q44.The upper stratosphere consisting of the ozone layer, protects us from the sun's radiation that falls in the wavelength region of (1) 200 −315 nm (2) 600 −750 nm (3) 400 −550 nm (4) 0 .8 −1 .5 nm