JEE Main 2025 · ChemistryNumerical answerNumerical valueMediumMulti-step

JEE Main 4 April 2025, Shift 2, Chemistry Q73

Question 73 of 75 in this shift, Chemistry question 23 of 25, Section B.

Sea water, which can be considered as a 6 molar (6 M) solution of NaCl, has a density of

2\ \mathrm{g\,mL^{-1}}

. The concentration of dissolved oxygen

(\mathrm{O_2})

in sea water is 5.8 ppm. Then the concentration of dissolved oxygen

(\mathrm{O_2})

in sea water, is

x\times10^{-4}

x=

__________. (Nearest integer) Given : Molar mass of NaCl is

58.5\ \mathrm{g\,mol^{-1}}

Molar mass of

\mathrm{O_2}

32\ \mathrm{g\,mol^{-1}}

Official answer

NTA final key.

Chapter: Solutions
Topic: Mole Concept
Idea tested: PPM and Mass Percentage

Same idea in other shifts

Asked 4× in all

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9 Jan 2020, Shift 2 · Q4710.30 mg of $\mathrm{O_2}$ is dissolved into a liter of sea water of density 1.03 g/mL. The concentration of $\mathrm{O_2}$ in ppm is…EasyNumerical value

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.