In a titration experiment, a balanced equation is provided and the concentrations of the NaOH(aq) and H₂SO₄(aq) are calculated as 2.0 mol/dm³ and 2.16 mol/dm³, respectively. The concentration of H₂SO₄(aq) is also calculated in g/dm², which is 211.307 g/dm². Additionally, five precautions to be taken during the titration experiment are stated.
(a) Balanced equation:
H₂SO₄ (aq) + 2NaOH (aq) → Na₂SO₄ (aq) + 2H₂O (l)
(b) Concentration:
- (i) NaOH(aq) in mol/dm³: Since 25.0 cm³ of NaOH(aq) contains 2.00 g of NaOH, we can calculate the molar mass of NaOH as 40.00 g/mol. Therefore, 2.00 g of NaOH is equal to 0.05 mol. So, the concentration of NaOH(aq) is 0.05 mol/0.025 dm³ or 2.0 mol/dm³.
- (ii) H₂SO₄(aq) in mol/dm³: From the balanced equation, we see that 1 mol of H₂SO₄ reacts with 2 mol of NaOH. Since it took 21.60 cm³ of H₂SO₄ to react with 25.0 cm³ of NaOH, the concentration of H₂SO₄ can be calculated as (0.05 mol/0.025 dm³) × (21.60 cm³/25.0 cm³) or 2.16 mol/dm³.
- (III) H₂SO₄(aq) in g/dm²: To calculate the concentration in g/dm², we multiply the molar mass of H₂SO₄ by its concentration in mol/dm³. The molar mass of H₂SO₄ is 98.09 g/mol, so the concentration in g/dm² is 2.16 mol/dm³ × 98.09 g/mol or 211.307 g/dm².
(c) Precautions:
- Use proper protective equipment like goggles and gloves.
- Measure the volumes accurately using a pipette or burette.
- Ensure the solutions are mixed thoroughly.
- Avoid parallax errors when reading the burette or pipette.
- Perform the titration in a well-ventilated area to avoid inhaling any fumes.