JEE Main 2020ChemistrySome Basic Concepts Of ChemistryConcentration TermsmediumMCQ

JEE Main 2020Some Basic Concepts Of Chemistry Question with Solution

From: JEE Main 2020 (Online) 6th September Morning Slot

Question

A solution of two components containing n1 moles of the 1st component and n2 moles of the 2nd component is prepared. M1 and M2 are the molecular weights of component 1 and 2 respectively. If d is the density of the solution in g mL–1, C2 is the molarity and x2 is the mole fraction of the 2nd component, then C2 can be expressed as :

Choose an option

Show full solutionCorrect option: B
Correct answer
B

Step-by-step explanation

1st component 2nd component
Mole n1 n2
Molecular
Weight
M1 M2
Mass n1M1 n2M2


Mass of solution = n1M1 + n2M2

density of the solution = d

C2 = Molarity of 2nd Component

x2 = Mole-fraction of 2nd Component

x2 =

1 - x2 =

Molarity of 2nd Component,

C2 =
n2
Volume of solution(ml)
1000

=

=

= (Dividing componendo and dividendo by n1 + n2)

=

=

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About this question

This is a previous-year question from JEE Main 2020, covering the Some Basic Concepts Of Chemistry chapter of Chemistry. PrepSharp catalogues every PYQ from JEE Main with a verified answer key and step-by-step solution prepared by IIT alumni — so you can search by chapter, topic or year and revise efficiently.