Learn

Friday, 9 October

JEE Main 2024 · ChemistryMultiple choiceSingle correctMediumCalculation

JEE Main 31 January 2024, Shift 2, Chemistry Q61

Question 61 of 90 in this shift, Chemistry question 1 of 30, Section A.

A sample of CaCO3\mathrm{CaCO_3} and MgCO3\mathrm{MgCO_3} 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^{-1} CaCO3\mathrm{CaCO_3} : 100, MgCO3\mathrm{MgCO_3} : 84)
  1. (1)1.023 g CaCO3\mathrm{CaCO_3} + 1.187 g MgCO3\mathrm{MgCO_3}
  2. (2)1.187 g CaCO3\mathrm{CaCO_3} + 1.023 g MgCO3\mathrm{MgCO_3}Official answer
  3. (3)1.023 g CaCO3\mathrm{CaCO_3} + 1.023 g MgCO3\mathrm{MgCO_3}
  4. (4)1.187 g CaCO3\mathrm{CaCO_3} + 1.187 g MgCO3\mathrm{MgCO_3}

Official answer

Option 2

NTA final key.

Chapter
Some Basic Concepts of Chemistry
Topic
Stoichiometry
Idea tested
Thermal Decomposition of Carbonates

Same topic in other shifts

All Stoichiometry questions
  1. 2 Apr 2026, Shift 1 · Q51The mass of iron converted into Fe3O4\mathrm{Fe_3O_4} by the action of 1818 g of steam is : (Given : Molar mass of H, O and Fe are 1,161, 16…EasySingle correct
  2. 2 Apr 2026, Shift 2 · Q51The 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)CO_2(g) formed…MediumSingle correct
  3. 2 Apr 2026, Shift 2 · Q62Complete combustion of X g of an organic compound gave 0.25 g of CO2CO_2 and 0.12 g of H2OH_2O. If the % of carbon is 25% and of hydrogen is…MediumSingle correct
  4. 2 Apr 2026, Shift 2 · Q75Consider the following reactions sequence…MediumNumerical value
  5. 4 Apr 2026, Shift 2 · Q75In sulphur estimation, 2.0×10−32.0\times10^{-3} mol of an organic compound (X) (molar mass 76 g mol−1\mathrm{g\ mol^{-1}}) gave 0.4813 g of barium…EasyNumerical value
  6. 5 Apr 2026, Shift 1 · Q51How 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…EasySingle correct

Question text from the official JEE Main paper published by NTA; answer from the final answer key. Chapter, topic and idea tags, difficulty and skill are Lumi’s. Lumi analyses 42 of the 174 JEE Main shifts held from 2017 to 2026.