Practice Questions

Q41.Which of the following can reduce decomposition of H2O2 on exposure to light (1) Urea (2) Alkali (3) Glass containers (4) Dust

Q41.An ammoniacal metal salt solution gives a brilliant red precipitate on addition of dimethylglyoxime. The metal ion is : (1) 𝐶𝑢2 + (2) 𝑁𝑖2 + (3) 𝐹𝑒2 + (4) Co2 +

Q41.Which of the following is used as a stabilizer during the concentration of sulphide ores? (1) Pine oils (2) Fatty acids (3) Xanthates (4) Cresols

Q41.The density of alkali metals is in the order (1) K < Cs < Na < Rb (2) Na < Rb < K < Cs (3) Na < K < Cs < Rb (4) K < Na < Rb < Cs

Q41.The delicate balance of CO2 and O2 is NOT disturbed by (1) Respiration (2) Burning of coal (3) Deforestation (4) Burning of petroleum

Q42.The correct relationships between unit cell edge length ‘a’ and radius of sphere ‘r’ for face-centred and body- centred cubic structures respectively are: (1) 2√2r = a and √3r = 4a (2) r = 2√2a and 4r = √3a (3) r = 2√2a and √3r = 4a (4) 2√2r = a and 4r = √3a

Q42.The correct order of basicity of oxides of vanadium is JEE Main 2023 (31 Jan Shift 1) JEE Main Previous Year Paper (1) V2O3 > V2O4 > V2O5 (2) V2O3 > V2O5 > V2O4 (3) V2O5 > V2O4 > V2O3 (4) V2O4 > V2O3 > V2O5

Q42.The concentration of dissolved Oxygen in water for growth of fish should be more than X ppm and ¯ Biochemical Oxygen Demand in clean water should be less than Y ppm. X and Y in ppm are, respectively. ¯ (1) X Y (2) X Y 6 5 4 8 (3) X Y (4) X Y 4 15 6 12

Q42.Which one of the following is not an example of calcination? (1) CaCO3 Δ→CaO + CO2 (2) Fe2 O3. xH2 O Δ→Fe2 O3 + xH2 O (3) (4) 2PbS + 3O2 Δ→2PbO + 2 SO2 CaCO3. MgCO3 Δ→CaO + MgO + 2 CO2

Q42.For a good quality cement, the ratio of lime to the total of the oxides of Si, Al and Fe should be as close as to (1) 4 (2) 1 (3) 2 (4) 3

Q43.Given below are two statements: One is labelled as Assertion A and the other is labelled as Reason R. Assertion A: can be easily reduced using Zn −Hg / HCl to Reason R: Zn −Hg / HCl is used to reduce carbonyl group to – CH2 – 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) A is true but R is false (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 of A

Q43.In Dumas method for the estimation of N2 , the sample is heated with copper oxide and the gas evolved is passed over: (1) Copper gauze (2) Pd (3) Ni (4) Copper oxide

Q43.Nd2 + = ______ (1) 4f26s2 (2) 4f4 (3) 4f3 (4) 4f46s2

Q43.Prolonged heating is avoided during the preparation of ferrous ammonium sulphate to (1) Prevent hydrolysis (2) Prevent reduction (3) Prevent breaking (4) Prevent oxidation

Q43.Match List I with List II List-I List-2 Species Maximum allowed concentration in ppm in drinking water A F− I < 50 ppm JEE Main 2023 (08 Apr Shift 1) JEE Main Previous Year Paper B SO2−4 II < 5 ppm C NO−3 III < 2 ppm D Zn IV < 500 ppm Choose the correct answer from the options given below. (1) A-I, B-II, C-III, D-IV (2) A-II, B-I, C-III, D-IV (3) A-IV, B-III, C-II, D-I (4) A-III, B-II, C-I, D-IV

Q43.Given below are two statements, one is labelled as Assertion A and the other is labelled as Reason R . Assertion A: can be subjected to Wolff-Kishner reduction to give Reason R: Wolff-Kishner reduction is used to convert into 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 and R is the correct (4) Both A and R are true and R is NOT the correct explanation of A explanation of A

Q43.The magnetic moment of a transition metal compound has been calculated to be 3 . 87 BM. The metal ion is (1) Cr2 + (2) Mn2 + (3) V2 + (4) Ti2 +

Q44.The industrial activity held least responsible for global warming is : (1) manufacturing of cement (2) steel manufacturing (3) Electricity generation in thermal power plants. (4) Industrial production of urea

Q44.The group of chemicals used as pesticide is (1) Aldrin, Sodium Chlorate, Sodium arsinite (2) DDT, Aldrin (3) Sodium chlorate, DDT, PAN (4) Dieldrin, Sodium arsinite, Tetrachloroethene

Q44.Three organic compounds A, B and C were allowed to run in thin layer chromatography using hexane and gave the following result (see figure). The Rf value of the most polar compound is _____ ×10–2

Q44.The primary and secondary valencies of cobalt respectively in Co ( NH3 ) 5ClCl2 are: (1) 3 and 5 (2) 2 and 6 (3) 2 and 8 (4) 3 and 6

Q44.Match List I with List II. List I List II A.van't Hoff I. Cryoscopic constant factor, i B. kf II. Isotonic solutions Solutions with same C. III. Normal molar mass osmotic pressure Abnormal molar mas Solutions with same composition D.Azeotropes IV. of vapour above it Choose the correct answer from the options given below: (1) A-III, B-I, C-II, D-IV (2) A-III, B-II, C-I, D-IV (3) A-III, B-I, C-IV, D-II (4) A-I, B-III, C-II, D-IV

Q44.The water quality of a pond was analysed and its BOD was found to be 4. The pond has (1) Highly polluted water (2) Water has high amount of fluoride compounds (3) Very clean water (4) Slightly polluted water

Q44.The covalency and oxidation state respectively of boron in BF4 -, are (1) 3 and 5 (2) 3 and 4 (3) 4 and 4 (4) 4 and 3

Q45. (i) O3 −2 −hexene → Products (ii) H2O The two products formed in above reaction are (1) Butanal and acetaldehyde (2) Butanoic acid and acetaldehyde (3) Butanal and acetic acid (4) Butanoic acid and acetic acid