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"My titration is taking more than 50
mL?"
Titrations requiring more than 50 mL of titrant are not expected. The buret is designed to deliver volumes up to 50 mL. When the buret is filled more than once the error due to successive volume readings is significant.
The volume of titrant required can be optimized before laboratory. The standard solution used in the titration experiment should be prepared so that the required volume does not exceed 50 mL. Thus, by approximating the concentration of the unknown, the desired concentration of the standard solution can be determined (see the example below).
Example
Determine the approximate concentration of a standard sodium hydroxide solution needed to titrate 5 mL of ~3.3 M HCl(aq).
M of base = unknown
V of base = 40 mL (half-way between 30 and 50 mL, the volume range where a buret is accurate)
M of acid = 3.3 M
V of acid = 5 mL
(M of base needed)(V of base needed) = (M of acid)(V of acid)
(M of base needed)(40 mL) = (3.3 M)(5 mL)
M of base needed = 0.4 M
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