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Some Basic Concepts of Chemistry

Previous year questions with solutions · 2024 – 2026

65Questions
52Papers covered
3.79%Weightage 2026▼ 33.3% vs last year
’24
’25
’26
Year-wise statistics questions · papers · average per paper · weightage
YearQuestionsPapersAvg / paperWeightage
202618190.953.79% ▼ 33.3% vs last year
202527191.45.68% ▲ 70.8% vs last year
202420210.953.33%

28 questions · newest paper first

Ques. 1JEE Main 2026, 5 April (Morning Shift)

How many grams of residue is obtained by heating 2.76 g of silver carbonate? (Given : Molar mass of C, O and Ag are 12, 16 and 108 g mol-1 respectively)

  1. 1.08 g
  2. 2.16 g
  3. 3.24 g
  4. 4.32 g
Ques. 2JEE Main 2026, 5 April (Evening Shift)

What volume of hydrogen gas at STP would be liberated by action of 50 mL of H2SO4 of 50% purity (density = 1.3 g mL-1) on 20 g of zinc? Given : Molar mass of H, O, S, Zn are 1, 16, 32, 65 g mol-1 respectively.

  1. 5.824 L
  2. 7.428 L
  3. 6.892 L
  4. 8.375 L
Ques. 3JEE Main 2026, 2 April (Morning Shift)

The mass of iron converted into Fe3O4 by the action of 18 g of steam is : (Given : Molar mass of H, O and Fe are 1, 16 and 56 g mol-1 respectively) Assume iron is present in excess :

  1. 2.1 g
  2. 4.2 g
  3. 21 g
  4. 42 g
Ques. 4JEE Main 2026, 2 April (Evening Shift)

The ratio of mass percentage (w/w) of C : H in a hydrocarbon is 12 : 1. It has two carbon atoms. The weight (in g) of CO2(g) formed when 3.38 g of this hydrocarbon is completely burnt in oxygen is : (Given : Molar mass in g mol-1 C : 12, H : 1, O : 16)

  1. 5.68
  2. 11.44
  3. 22.74
  4. 17.05
Ques. 5JEE Main 2026, 28 January (Evening Shift)

For the given reaction; CaCO3 + 2HCl CaCl2 + H2O + CO2 If 90 g CaCO3 is added to 300 mL of HCl which contains 38.55% HCl by mass and has density 1.13 g mL-1, then which of the following option is correct? Given molar mass of H, Cl, Ca and O are 1, 35.5, 40 and 16 g mol-1 respectively.

  1. 64.97 g of HCl remains unreacted
  2. 60.32 g of HCl remains unreacted
  3. 32.85 g of CaCO3 remains unreacted
  4. 97.30 g of HCl reacted
Ques. 6JEE Main 2026, 22 January (Morning Shift)

In the reaction, 2Al(s) + 6HCl(aq) 2Al3+(aq) + 6Cl-(aq) + 3H2(g)

  1. 12 L HCl(aq) is consumed for every 6 L H2(g) produced.
  2. 11.2 L H2(g) at STP is produced for every mole of HCl consumed.
  3. 33.6 L H2(g) is produced regardless of temperature and pressure for every mole of Al that reacts.
  4. 67.2 L H2(g) at STP is produced for every mole of Al that reacts.
Ques. 7JEE Main 2026, 22 January (Evening Shift)

A + 2B AB2 36.0 g of 'A' (Molar mass : 60 g mol-1) and 56.0 g of 'B' (Molar mass : 80 g mol-1) are allowed to react. Which of the following statements are correct ? Choose the correct answer from the options given below :

  1. A and C Only
  2. A and B Only
  3. C and D Only
  4. B and D Only
Ques. 8JEE Main 2026, 21 January (Morning Shift)

14.0 g of calcium metal is allowed to react with excess HCl at 1.0 atm pressure and 273 K. Which of the following statements is incorrect? [Given : Molar mass in g mol-1 of Ca – 40, Cl – 35.5, H – 1]

  1. The limiting reagent is calcium metal.
  2. 33.3 g of CaCl2 is produced.
  3. 7.84 L of H2 gas is evolved.
  4. 0.35 mol of H2 gas is evolved.
Ques. 9JEE Main 2026, 21 January (Morning Shift)

80 mL of a hydrocarbon on mixing with 264 mL of oxygen in a closed U-tube undergoes complete combustion. The residual gases after cooling to 273 K occupy 224 mL. When the system is treated with KOH solution, the volume decreases to 64 mL. The formula of the hydrocarbon is :

  1. C2H2
  2. C2H4
  3. C4H10
  4. C2H6
Ques. 10JEE Main 2026, 21 January (Evening Shift)

Aqueous HCl reacts with MnO2(s) to form MnCl2(aq), Cl2(g), and H2O(l). What is the weight (in g) of Cl2 liberated when 8.7 g of MnO2(s) is reacted with excess aqueous HCl solution? (Given Molar mass in g mol-1 Mn = 55, Cl = 35.5, O = 16, H = 1)

  1. 14.2
  2. 21.3
  3. 7.1
  4. 71
Ques. 11JEE Main 2025, 8 April (Evening Shift)

20 mL of sodium iodide solution gave 4.74 g silver iodide when treated with excess of silver nitrate solution. The molarity of the sodium iodide solution is M. (Nearest Integer value) (Given : Na = 23, I = 127, Ag = 108, N = 14, O = 16 g mol-1)

Ques. 12JEE Main 2025, 7 April (Evening Shift)

Butane reacts with oxygen to produce carbon dioxide and water following the equation given below. C4H10(g) + 132O2(g) 4CO2(g) + 5H2O(l) If 174.0 kg of butane is mixed with 320.0 kg of O2, the volume of water formed in liters is . (Nearest integer) [Given : (a) Molar mass of C, H, O are 12, 1, 16 g mol-1 respectively, (b) Density of water = 1 g mL-1]

Ques. 13JEE Main 2025, 3 April (Evening Shift)

Mass of magnesium required to produce 220 mL of hydrogen gas at STP on reaction with excess of dil. HCl is Given: Molar mass of Mg is 24 g mol-1.

  1. 0.24 mg
  2. 235.7 g
  3. 2.444 g
  4. 236 mg
Ques. 14JEE Main 2025, 3 April (Evening Shift)

X g of nitrobenzene on nitration gave 4.2 g of m-dinitrobenzene. X = g. (nearest integer) [Given : molar mass (in g mol-1) C : 12, H : 1, O : 16, N : 14]

Ques. 15JEE Main 2025, 2 April (Morning Shift)

CaCO3(s)+2HCl(aq) CaCl2(aq)+CO2(g)+H2O(l) Consider the above reaction, what mass of CaCl2 will be formed if 250 mL of 0.76 M HCl reacts with 1000 g of CaCO3 ? (Given : Molar mass of Ca, C, O, H and Cl are 40, 12, 16, 1 and 35.5 g mol-1, respectively)

  1. 3.908 g
  2. 2.636 g
  3. 10.545 g
  4. 5.272 g
Ques. 16JEE Main 2025, 29 January (Evening Shift)

0.1 M solution of KI reacts with excess of H2SO4 and KIO3 solutions. According to equation 5I- + IO3- + 6H+ 3I2 + 3H2O Identify the correct statements : Choose the correct answer from the options given below :

  1. (C) and (D) only
  2. (A) and (B) only
  3. (B) and (C) only
  4. (A) and (D) only
Ques. 17JEE Main 2025, 24 January (Morning Shift)

Consider the following reaction occurring in the blast furnace: Fe3O4(s) + 4CO(g) 3Fe(l) + 4CO2(g) 'x' kg of iron is produced when 2.32 103 kg Fe3O4 and 2.8 102 kg CO are brought together in the furnace. The value of 'x' is . (nearest integer) Given: molar mass of Fe3O4 = 232 g mol-1 molar mass of CO = 28 g mol-1 molar mass of Fe = 56 g mol-1

Ques. 18JEE Main 2025, 24 January (Morning Shift)

Xg of benzoic acid on reaction with aq NaHCO3 released CO2 that occupied 11.2 L volume at STP. X is g.

Ques. 19JEE Main 2025, 23 January (Morning Shift)

What amount of bromine will be required to convert 2 g of phenol into 2,4,6-tribromophenol? (Given molar mass in g mol-1 of C, H, O, Br are 12, 1, 16, 80 respectively )

  1. 6.0 g
  2. 10.22 g
  3. 20.44 g
  4. 4.0 g
Ques. 20JEE Main 2025, 23 January (Evening Shift)

When 81.0 g of aluminium is allowed to react with 128.0 g of oxygen gas, the mass of aluminium oxide produced in grams is . (Nearest integer) Given : Molar mass of Al is 27.0 g mol-1 Molar mass of O is 16.0 g mol-1

Ques. 21JEE Main 2025, 22 January (Morning Shift)

Some CO2 gas was kept in a sealed container at a pressure of 1 atm and at 273 K. This entire amount of CO2 gas was later passed through an aqueous solution of Ca(OH)2. The excess unreacted Ca(OH)2 was later neutralized with 0.1 M of 40 mL HCl. If the volume of the sealed container of CO2 was x, then x is cm3 (nearest integer). [Given : The entire amount of CO2(g) reacted with exactly half the initial amount of Ca(OH)2 present in the aqueous solution.]

Ques. 22JEE Main 2024, 8 April (Morning Shift)

Combustion of glucose ( C6H12O6) produces CO2 and water. The amount of oxygen (in g) required for the complete combustion of 900 g of glucose is : [Molar mass of glucose in g mol-1 = 180]

  1. 32
  2. 480
  3. 800
  4. 960
Ques. 23JEE Main 2024, 5 April (Evening Shift)

The number of moles of methane required to produce 11 g CO2(g) after complete combustion is : (Given molar mass of methane in g mol-1 : 16)

  1. 0.35
  2. 0.25
  3. 0.5
  4. 0.75
Ques. 24JEE Main 2024, 1 February (Morning Shift)

Consider the following reaction : 3PbCl2 + 2(NH4)3PO4 Pb3(PO4)2 + 6NH4Cl If 72 mmol of PbCl2 is mixed with 50 mmol of (NH4)3PO4, then the amount of Pb3(PO4)2 formed is mmol (nearest integer).

Ques. 25JEE Main 2024, 1 February (Evening Shift)

10 mL of gaseous hydrocarbon on combustion gives 40 mL of CO2(g) and 50 mL of water vapour. Total number of carbon and hydrogen atoms in the hydrocarbon is .

Ques. 26JEE Main 2024, 31 January (Morning Shift)

Number of moles of methane required to produce 22 g CO2(g) after combustion is x 10-2 moles. The value of x is .

Ques. 27JEE Main 2024, 31 January (Evening Shift)

A sample of CaCO3 and MgCO3 weighed 2.21 g is ignited to constant weight of 1.152 g. The composition of mixture is : (Given molar mass in g mol-1 CaCO3 : 100, MgCO3 : 84)

  1. 1.187 g CaCO3 + 1.187 g MgCO3
  2. 1.187 g CaCO3 + 1.023 g MgCO3
  3. 1.023 g CaCO3 + 1.187 g MgCO3
  4. 1.023 g CaCO3 + 1.023 g MgCO3
Ques. 28JEE Main 2024, 27 January (Morning Shift)

Mass of methane required to produce 22 g of CO2 after complete combustion is g. (Given Molar mass in g mol-1 C = 12.0, H = 1.0, O = 16.0)