would read it as 20.18 mL.

Someone else might have a

slightly different estimation of

the last digit maybe they think

it is 20.16 mL or 20.19 mL.

This slight disagreement is fine

and gives an approximation of

the uncertainty of the

measurement. I would record

this value with four significant

digits since my last recorded

digit should be the one that

has uncertainty.

Buret readings should be

recorded to 2 decimal

places.

We determine the volume of

liquid delivered by reading the

volume at the beginning of the

titration and then reading the

volume again at the end of the

titration. The volume delivered

is then the difference between

those two readings:

Buret Preparation

We prep the buret by first rinsing with water multiple times and then rinsing

multiple times with the titrant solution we are using. To rinse the buret, we use

about 15 mL of liquid for each rinsing. Put the liquid into the buret with the

stopcock closed (perpendicular to the tip). Then slowly tilt the buret so that the

liquid touches all of the interior surface and finally allow the liquid to run out the

tip of the buret.

47

Figure 6.2: "Buret" by photobunny is licensed under CC BY-NC-

ND 2.0.