Preparation of 0.1M solution of Sulfuric Acid (H₂SO₄), start by calculating the volume of concentrated acid required. Concentrated sulfuric acid (98% by weight, density ~1.84 g/mL) contains approximately 1.8032 g of H₂SO₄ per mL. To prepare 1 liter of 0.1 M solution, you need 0.1 moles of H₂SO₄, equivalent to 9.808 g, which corresponds to 5.44 mL of concentrated acid. Always prioritize safety by wearing gloves, goggles, and a lab coat and work in a well-ventilated area. Using a pipette or burette, carefully measure 5.44 mL of concentrated sulfuric acid and slowly add it to about 800 mL of distilled water in a large container—always adding acid to water to prevent splashing or a violent reaction. Stir the solution gently, then transfer it to a 1 L volumetric flask. Rinse the container with distilled water, add the washings to the flask, and dilute with distilled water to the 1 L mark. Finally, mix the solution thoroughly and label it with the concentration and preparation date.
Materials Needed:
- Concentrated sulfuric acid (H₂SO₄, usually 98% by weight with a density of ~1.84 g/mL).
- Distilled or deionized water.
- Volumetric flask (1 L capacity for 1 liter of solution, or appropriate size for the volume you need).
- Pipette or burette for measuring concentrated sulfuric acid.
- Protective equipment (gloves, safety goggles, lab coat).
Calculation:
The molar mass of H₂SO₄ is approximately 98.08 g/mol.
1.0 Concentrated sulfuric acid (98%) has:
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- Density: ~1.84 g/mL.
- Mass percent: 98% H₂SO₄ by weight.
Thus, 1 mL of concentrated sulfuric acid contains:
Mass of H₂SO₄ in 1 mL=Density×Mass percent=1.84g/mL×0.98≈1.8032g/mL.
2.0 To prepare a 0.1 M solution:
Moles of H₂SO₄ required in 1 L=0.1mol.
Mass of H₂SO₄ required=0.1mol×98.08g/mol≈9.808g.
3.0 Volume of concentrated H₂SO₄ to use:
Volume (mL)=Mass of H₂SO₄/Mass of H₂SO₄ per mL=9.808/1.8032≈5.44mL.
Procedure:
- Safety first: Put on gloves, safety goggles, and a lab coat. Work in a fume hood if possible.
- Dilution:
- Measure 5.44 mL of concentrated sulfuric acid using a pipette or burette.
- Slowly add the acid to about 800 mL of distilled water in a large beaker or flask. Always add acid to water, never water to acid, to prevent splashing or exothermic reactions.
- Mix the solution gently to ensure proper dilution.
- Transfer and adjust volume:
- Transfer the diluted solution to a 1 L volumetric flask.
- Rinse the beaker and transfer washings into the flask to ensure no acid is left behind.
- Add distilled water up to the 1 L mark on the flask.
- Mix thoroughly: Invert the flask several times to ensure homogeneity.
Notes:
- Always handle concentrated acids with care.
- Ensure accurate measurements for precise molarity.
- Label the prepared solution with its concentration and preparation date.