X g of ethylamine is subjected to reaction with NaNO₂/HCl followed by water; evolved dinitrogen gas which occupied 2.24 L volume at STP. X is _____

The Molarity of NaCl Solution | JEE Mains Previous Year Question | Mole Concept

Q. The Molarity (M) of an aqueous solution containing 5.85 g of NaCl in 500 mL water is : (Given : Molar Mass Na : 23 and Cl : 35.5 g mol⁻¹)

A. 20

B. 4

C. 2

D. 0.2

Step by Step Solution

Step 1: Calculate molar mass of NaCl

Molar mass of NaCl = 23 + 35.5 = 58.5 g mol⁻¹

Step 2: Calculate number of moles of NaCl

Moles of NaCl = 5.85 / 58.5 = 0.1 mol

Step 3: Convert volume into litres

500 mL = 0.5 L

Step 4: Calculate molarity

Molarity = Moles / Volume (L) = 0.1 / 0.5 = 0.2 M

Final Answer: 0.2 M

Previous Year Questions – Mole Concept