Answer to Question #350149 in General Chemistry for DEBORAH

Question

 What weight of pure Na₂CO₃ should be taken so that about 25mL of  approximately 0.1M HCl will be used in a standardization titration using methyl    red end point?

Answer 1

Solution:

Balanced chemical equation:

Na₂CO₃ + 2HCl → 2NaCl + H₂O + CO₂

According to stoichiometry:

Moles of Na₂CO₃ = Moles of HCl / 2

Moles of Na₂CO₃ = (Molarity of HCl × Volume of HCl) / 2

Moles of Na₂CO₃ = (0.1 M × 0.025) / 2 = 0.00125 mol

The molar mass of Na₂CO₃ is 106 g/mol

Therefore,

Mass of Na₂CO₃ = (0.00125 mol Na₂CO₃) × (106 g Na₂CO₃ / 1 mol Na₂CO₃) = 0.1325 g Na₂CO₃

Answer: 0.1325 grams of Na₂CO₃