Titration

Using an acid (or base) of known concentration to neutralize a base (or acid) of unknown concentration. –Using the burets and indicator

Acid-Base Titration Curve A plot of the pH of the soln with unknown concentration vs. the volume of the soln with known concentration.

Strong A/B Titration pH changes slowly until the equivalence point is neared, (the amount necessary to neutralize based on stoich), then it changes quickly. Once the equivalence point is passed, the curve flattens out once again.

Calculate the pH of a soln of 10mL 0.1M NaOH added to 25mL of 0.1M HCl.

What’s the pH of a soln of 15mL 0.1M NaOH and 25mL of 0.1M HCl?

Titration of Weak A by Strong B Weak A & Strong B produce a basic salt; therefore these curves start higher and the equivalence point is above 7.

Calc pH for a soln at the equivalence point when 25mL 0.1M nicotinic acid is titrated by 0.1M NaOH. K a = 1.4*10 -5

What is the pH at the equivalence point when 25mL of 0.1M HF is titrated by 0.15M NaOH?

Titration of Weak B with Strong A This curve is flipped from the other two – it starts with high pH and then goes low (adding acid).

What is the pH at the equivalence point when 35mL of 0.20M NH 3 is titrated by 0.12M HCl? K b = 1.8*10 -5

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