Preparation and standardization of a 0.1 M H₂SO₄ solution involve dilution of concentrated acid and verification using titration.
Step 1: Calculate required moles
M = 0.1 M
V = 250 mL = 0.25 L
moles = M × V = 0.1 × 0.25 = 0.025 mol
Step 2: Dilution from concentrated H₂SO₄
- Concentrated H₂SO₄ is typically ~18 M
Use dilution formula:
M₁V₁ = M₂V₂
18 × V₁ = 0.1 × 250
V₁ = (25) / 18 = 1.39 mL
Step 3: Preparation procedure
- Take ~100 mL distilled water in a flask
- Carefully add 1.39 mL concentrated H₂SO₄ (always add acid to water)
- Mix and dilute up to 250 mL
- Stir well
Step 4: Standardization
- Use a standard solution (e.g., Na₂CO₃)
- Perform titration
- Use an appropriate indicator (like methyl orange)
- Calculate actual molarity using titration data
Safety Note:
- Always add acid to water, never the reverse
- Wear gloves and eye protection
Key Takeaway:
Prepare by dilution using M₁V₁ = M₂V₂, then standardize via titration to ensure accurate concentration.