JEE Main PYQs Mole Concept – Some Basic Concepts of Chemistry | NEET JEE Rankers

10 mL of 2 M NaOH solution is added to 20 mL of 1 M HCl solution kept in a beaker. Now, 10 mL of this mixture is poured into a volumetric flask of 100 mL containing 2 moles of HCl and made the volume upto the mark with distilled water. The solution in this flask is :

Step by Step Solution

Step 1: Moles of NaOH = 2 × (10 / 1000) = 0.02 moles

Step 2: Moles of HCl = 1 × (20 / 1000) = 0.02 moles

Step 3: Equal moles of NaOH and HCl neutralise each other completely.

Step 4: 10 mL of this neutral solution is taken and added to a flask containing 2 moles of HCl.

Step 5: Final volume = 100 mL = 0.1 L

Step 6: Molarity of HCl = 2 / 0.1 = 20 M

✅ Final Answer: 20 M HCl solution