Practice Questions

Q38.An analyst wants to convert 1 L HCl of pH = 1 to a solution of HCl of pH = 2. The volume of water needed to do this dilution is _____ mL. (Nearest integer)

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

Q45.For the first order reaction A →B the half life is 30 min. The time taken for 75% completion of the reaction is mm. (Nearest integer) Given : log 2 = 0. 3010 log 3 = 0. 4771 log 5 = 0. 6989

Q46.For conversion of compound A →B, the rate constant of the reaction was found to be 4. 6 × 10−5 Lmol −1 s−1 . The order of the reaction is _____ .

Q46.The number of units, which are used to express concentration of solutions from the following is _________. (Mass percent, Mole, Mole fraction, Molarity, ppm, Molality.)

Q48.The resistivity of a 0. 8M solution of an electrolyte is 5 × 10−3Ωcm. Its molar conductivity is 104Ω−1 cm2 mol−1 . (Nearest integer)

Q48. t87.5 is the time required for the reaction to undergo 87. 5% completion and t50 is the time required for the reaction to undergo 50% completion. The relation between t87.5 and t50 for a first order reaction is t87.5 = x × t50 The value of x is _________. (Nearest integer)

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

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

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)

Q52.For a metal ion, the calculated magnetic moment is 4 . 90 BM. This metal ion has _______ number of unpaired electrons

Q52.When 2 litre of ideal gas expands isothermally into vacuum to a total volume of 6 litre, the change in internal energy is _____ J. (Nearest integer) Q53.600mL of 0 . 01M HCl is mixed with 400mL of 0 . 01M H2SO4. The pH of the mixture is _____ × 10-2. (Nearest integer) [Given log2 = 0 . 30, log3 = 0 . 48, log5 = 0 . 69, log7 = 0 . 84, log11 = 1 . 04]

Q52.The orbital angular momentum of an electron in 3 s orbital is 2π.xh The value of Q53.20 mL of 0 . 1MNaOH is added to 50 mL of 0 . 1M acetic acid solution. The pH of the resulting solution is × 10-2. (Nearest integer) Given : pK𝑎CH3COOH = 4 . 76 log 2 = 0 . 30 log 3 = 0 . 48

Q53.The total change in the oxidation state of manganese involved in the reaction of KMnO4 and potassium iodide in the acidic medium is ________.

Q53.At constant temperature, a gas is at a pressure of 940 . 3 mm Hg. The pressure at which its volume decreases by 40% is ______ mm Hg. (Nearest integer) +2 . 2 V +0 . 70 V -0 . 45 V 2 - ⟶ Fe3 + ⟶ Fe2 + ⟶ Fe0

Q53.The denticity of the ligand present in the Fehling's reagent is _____ .

Q54.See the following chemical reaction: Cr2O72 - + XH+ + 6Fe2 + →YCr3 + + 6Fe3 + + ZH2O The sum of X, Y and Z is

Q55.The sum of oxidation state of the metals in Fe(CO)5 , VO2+ and WO3 is

Q55.When Fe0 . 93O is heated in presence of oxygen, it converts to Fe2O3. The number of correct statement/s from the following is ______ . A. The equivalent weight of Fe0 . 93O is Molecular0 . 79weight B. The number of moles of Fe2 + and Fe3 + in 1 mole of Fe0 . 93O is 0 . 79 and 0 . 14 respectively. C. Fe0 . 93O is metal deficient with lattice comprising of cubic closed packed arrangement of O2 - ions. D. The % composition of Fe2 + and Fe3 + in Fe0 . 93O is 85% and 15% respectively. Q56.5 g of NaOH was dissolved in deionized water to prepare a 450 mL stock solution. What volume (in mL) of this solution would be required to prepare 500 mL of 0 . 1 M solution ? Given : Molar Mass of Na, O and H is 23, 16 and 1 g mol – 1 respectively

Q56.In alkaline medium, the reduction of permanganate anion involves a gain of ____________ electrons.

Q57.In the following reaction, the total number of oxygen atoms in 𝑋 and 𝑌 is______ Na2O + H2O →2X Cl2O7 + H2O →2Y

Q58.Among the following, the number of tranquilizer/s is/are A. Chloroliazepoxide B. Veronal C. Valium D. Salvarsan

Q58.The number of correct statement/s from the following is _____ . A.Larger the activation energy, smaller is the value of the rate constant. B. The higher is the activation energy, higher is the value of the temperature coefficient. C. At lower temperatures, increase in temperature causes more change in the value of k than at higher temperature. D. A plot of ln k vs 1 is a straight line with slope equal to -Ea T R

Q59.The oxidation sate of phosphorus in hypophosphoric acid is