Practice Questions

Q50.The reaction used for preparation of soap from fat is : (1) An addition reaction (2) Reduction reaction (3) Alkaline hydrolysis reaction (4) An oxidation reaction

Q50.Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): Ketoses give Seliwanoff’s test faster than Aldoses. Reason (R): Ketoses undergo 𝛽-elimination followed by formation of furfural. 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 true and (R) is the correct explanation of (A) (3) (A) is true but (R) is false (4) Both (A) and (R) are true but (R) is not the correct explanation of (A)

Q50.Coagulating value of the electrolytes AlCl3 and NaCl tor As2 S3 are 0. 09 and 50. 04 respectively. The coagulating power of AlCl3 is x times the coagulating power of NaCl. The value of x is

Q50.The one that does not stabilize 2∘ and 3∘ structures of proteins is (1) – S – S – linkage (2) H - bonding (3) – O – O – linkage (4) van der Waals forces

Q51.The total number of isoelectronic species from the given set is ________. O2−, F–, Al, Mg2+, Na+, O+, Mg, Al3+, F Q52. 30. 4 kJ of heat is required to melt one mole of sodium chloride and the entropy change at the melting point is 28. 4 J K–1 mol–1 at 1 atm. The melting point of sodium chloride is _______ K (Nearest Integer)

Q51. K2 Cr2 O7 paper acidified with dilute H2 SO4 turns green when exposed to (1) Carbon dioxide (2) Sulphur trioxide (3) Hydrogen sulphide (4) Sulphur dioxide

Q51. The electron in the nth orbit of Li2 + is excited to ( n + 1 ) orbit using the radiation of energy 1 . 47 × 10-17 J (as shown in the diagram). The value of n is ___________ Given : RH = 2 . 18 × 10-18 J

Q51.The energy of one mole of photons of radiation of frequency 2 × 1012 Hz in Jmol-1 is _____ . (Nearest integer) (Given: h = 6 . 626 × 10-34Js NA = 6 . 022 × 1023 mol-1)

Q51.Given below are two statements, one is labelled as Assertion A and the other is labelled as Reasom R. Assertion A: A solution of the product obtained by heating a mole of glycine with a mole of chlorine in presence of red phosphorous generates chiral carbon atom. Reason R: A molecule with 2 chiral carbons is always optically active. In the light of above statements, chose the correct answer from the options given below: (1) A is true but R is false (2) Both A and R are true but R is the correct explaination of A (3) A is false but R is true (4) Both A and R are true but R is NOT the correct explaination of A

Q51.Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R Assertion A: In the Ellingham diagram, a sharp change in slope of the line is observed from Mg →MgO at ~1120oC Reason R: There is a large change of entropy associated with the change of state In the light of the above statements, choose the correct answer from the options given below (1) Both A and R are true but R is NOT the correct (2) A is false but R is true explanation of A (3) Both A and R are true and R is the correct (4) A is true but R is false explanation of A

Q51.The set of correct statements is: (i) Manganese exhibits +7 oxidation state in its oxide. (ii) Ruthenium and Osmium exhibit +8 oxidation in their oxides. (iii) Sc shows +4 oxidation state which is oxidizing in nature. (iv) Cr shows oxidising nature in +6 oxidation state. (1) (ii) and (iii) (2) (i), (ii) and (iv) (3) (i) and (iii) (4) (ii), (iii) and (iv)

Q51.Among following compounds, the number of those present in copper matte is A. CuCO3 B. Cu2 S C. Cu2 O D. FeO

Q51.The number of bent-shaped molecule/s from the following is ______ N3- , NO2- , I3- , O3, SO2

Q51.A solution of sugar is obtained by mixing 200 g of its 25% solution and 500 g of its 40 % solution (both by mass). The mass percentage of the resulting sugar solution is _______ (Nearest integer) JEE Main 2023 (11 Apr Shift 1) JEE Main Previous Year Paper

Q51.Formulae for Nessler's reagent is: (1) KHg2 I2 (2) KHgI3 (3) K2 HgI4 (4) HgI2

Q51.Which one of the following statements is incorrect ? (1) van Arkel method is used to purify tungsten. (2) The malleable iron is prepared from cast iron by oxidising impurities in a reverberatory furnace. (3) Cast iron is obtained by melting pig iron with (4) Boron and Indium can be purified by zone scrap iron and coke using hot air blast. refining method.

Q51.Potassium dichromate acts as a strong oxidizing agent in acidic solution. During this process, the oxidation state changes from (1) +3 to +1 (2) +6 to +3 (3) +2 to +1 (4) +6 to +2

Q51.The reaction representing the Mond process for metal refining is ______ (1) Δ (2) Δ Ni + 4CO 2K[Au(CN)2] + Zn →K2[Zn(CN)4] + 2 Au →Ni(CO)4 (3) Δ (4) Δ Zr + 2I2 →ZrI4 ZnO + C →Zn + CO Q52.“ A ” obtained by Ostwald's method involving air oxidation of NH3 , upon further air oxidation produces “ B ”. “ B ” on hydration forms an oxoacid of Nitrogen along with evolution of “ A ”. The oxoacid also produces “ A ” and gives positive brown ring test (1) NO2, N2O5 (2) NO2, N2O4 (3) NO, NO2 (4) N2O3, NO2

Q51.The incorrect statement from the following for borazine is: (1) It contains banana bonds (2) It can react with water (3) It is a cyclic compound (4) It has electronic delocalization

Q51.The density of 3M solution of NaCl is 1 . 0 g mL-1. Molality of the solution is ______ × 10-2 m (Nearest integer). Given: Molar mass of Na and Cl is 23 and 35 . 5 g mol-1 respectively.

Q51.In chromyl chloride, the number of d-electrons present on chromium is same as in (Given at no. of Ti : 22, V : 23, Cr : 24, Mn : 25, Fe : 26 ) (1) V (IV) (2) Mn (VII) (3) Fe (III) (4) Ti (III)

Q51.If 5 moles of BaCl2 is mixed with 2 moles of Na3PO4, the maximum number of moles of Ba3PO42formed is _________ (Nearest integer)

Q51.In Hall-Heroult process, the following is used for reducing Al2 O3 :- (1) Magnesium (2) Na3 AlF6 (3) Graphite (4) CaF2

Q51.The number of paramagnetic species from the following is [Ni(CN)4]2−, [Ni(CO)4], [NiCl4]2− [Fe(CN)6]4−, [Cu (NH3)4]2+ [Fe(CN)6]3− and [Fe (H2O)6]2+

Q51.On complete combustion, 0 . 492 g of an organic compound gave 0 . 792 g of CO2. The % of carbon in the organic compound is (Nearest integer)