Learn

Saturday, 31 October

JEE Main 2021 · ChemistryNumerical answerNumerical valueEasyCalculation

JEE Main 18 March 2021, Shift 2, Chemistry Q59

Question 59 of 90 in this shift, Chemistry question 29 of 30, Section B.

[figure: reaction scheme] Consider the above reaction where 6.1 g of Benzoic acid is used to get 7.8 g of m-bromo benzoic acid. The percentage yield of the product is __________. (Round off to the Nearest Integer). [Given : Atomic masses : C : 12.0 u, H : 1.0 u, O : 16.0 u, Br : 80.0 u]

The figure, in words

Drawn: benzene ring with COOH, + Br2, arrow labelled FeBr3, product benzene ring with COOH at top and Br on a ring carbon separated from the COOH carbon by one ring carbon (drawn at lower right), + HBr.

Official answer

78

NTA final key.

Chapter
Some Basic Concepts of Chemistry
Topic
Stoichiometry
Idea tested
Theoretical and Percent Yield

Same idea in other shifts

Asked 7× in all
  1. 27 Jul 2022, Shift 2 · Q90In the above reaction, 5 g of toluene is converted into benzaldehyde with 92% yield. The amount of benzaldehyde produced is __________…EasyNumerical valueHas a figure
  2. 29 Jul 2022, Shift 1 · Q89In bromination of Propyne, with Bromine 1, 1, 2, 2-tetrabromopropane is obtained in 27% yield. The amount of 1, 1, 2, 2-tetrabromopropane…MediumNumerical value
  3. 24 Feb 2021, Shift 2 · Q601.86 g of aniline completely reacts to form acetanilide. 10% of the product is lost during purification. Amount of acetanilide obtained…EasyNumerical value
  4. 22 Jul 2021, Shift 2 · Q60Methylation of 10 g of benzene gave 9.2 g of toluene. Calculate the percentage yield of toluene ________. (Nearest integer)EasyNumerical value
  5. 17 Mar 2021, Shift 1 · Q60[reaction drawn: see figure_note] In the above reaction, 3.9 g of benzene on nitration gives 4.92 g of nitrobenzene. The percentage yield…EasyNumerical valueHas a figure
  6. 17 Mar 2021, Shift 2 · Q60[reaction scheme] Consider the above reaction. The percentage yield of amide product is __________. (Round off to the Nearest Integer).…MediumNumerical valueHas a figure

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. This question needs a figure we do not reproduce; it is described in words above. Lumi analyses 108 of the 174 JEE Main shifts held from 2017 to 2026.