Practice: The mass of an empty container at 28 ** ^{o}**C is 83.93 g. The mass of the container when filled with water from a 25-mL pipet is 108.70 g. Calculate the true volume of delivered water by the calibrated pipet.

Concept #1: Temperature can have an adverse effect on determing the true mass or volume of a solution.

Example #1: Massachusetts limits the amount of lead in drinking water to 219 ppb. a) Express this total in molarity. b) What will happen to the molarity of the solution as the temperature increases: will it increase, decrease or remain constant?

Example #2: If a 0.02135 M aqueous solution is prepared at 21^{o}C (d = 0.9979955 g/mL) what is the new concentration if the same experiment is performed a month later when the temperature is now 26 ^{o}C (d = 0.9967867 g/mL)?

Practice: The mass of an empty container at 28 ** ^{o}**C is 83.93 g. The mass of the container when filled with water from a 25-mL pipet is 108.70 g. Calculate the true volume of delivered water by the calibrated pipet.