Q.26 Molarity is defined as

1. No. of moles of solute in 1 liter of solution
2. No. of moles of solute in 1 kg of solvent
3. No. of moles of solvent in 1 kg of solute
4. No. of moles of salt in 1 liter of solvent

   Molarity is defined as the number of moles of solute dissolved in 1 liter of solution, a key measure of concentration in chemistry.

   Correct Answer

   1. No. of moles of solute in 1 liter of solution

   Option Analysis

   • 1. No. of moles of solute in 1 liter of solution: Correct. Molarity (M) quantifies solute concentration as moles per liter of total solution volume (M = n/V, where n = moles solute, V = liters solution), temperature-sensitive due to volume changes.

   • 2. No. of moles of solute in 1 kg of solvent: Incorrect. This defines molality (m), a mass-based unit independent of temperature, used for colligative properties.

   • 3. No. of moles of solvent in 1 kg of solute: Incorrect. This resembles mole fraction inverse or unrelated; no standard term matches, as it focuses on solvent rather than solute.​

   • 4. No. of moles of salt in 1 liter of solvent: Incorrect. This confuses solution (solute + solvent) with pure solvent volume; molarity uses total solution volume, and “salt” limits to ionic compounds.​

   Molarity definition moles solute 1 liter solution is the standard for expressing concentration in aqueous chemistry. Denoted as M (mol/L), it equals moles of solute divided by solution volume in liters, crucial for titrations and stoichiometry.

   Molarity Formula

   M = n / V (n = moles solute = mass/molar mass; V = liters solution). Example: 58.5 g NaCl (1 mol) in 1 L water yields ~1 M (actual volume slightly over 1 L).

   Comparisons

   Term	Definition	Unit Basis
   Molarity	Moles solute per liter solution	Volume ​
   Molality	Moles solute per kg solvent	Mass ​
   Moles solvent/kg solute	Non-standard	Inverse ​
   Moles salt/liter solvent	Incorrect for molarity	Solvent only ​

   Applications

   Molarity definition moles solute 1 liter solution standardizes reactions; temperature affects it unlike molality. Used in labs for dilutions (M1V1 = M2V2).