Pre-lab questions:
Q 1. Based on the Three Source of Error
Three sources of error in acid-base titration
1. We notice the colour change of the solution due to presenceof indicator at the end point (one extra drop from buret added tosolution in conical flask after equivalence point) and not at theequivalence point (when a number of moles of acid=number of molesof base).
2. Parallax error: When we take the reading of solution in theburet from an angle rather than looking straight at the lowermeniscus in colorless solutions and upper meniscus in coloredsolutions, this gives an error in the final calculation of themolarity of our acid.
3. The precision of the buret: Some burets may be less precisethan others in giving the correct reading. This increases theuncertainty in the measurement of the volume of titrant used.
a) Give specific ways that you might avoid each one
b) During titration of an acid with a base, the sides of theErlenmeyer flask are washed with distilled water. Do you think thisrinsing will affect the outcome of the titration? Why or whynot?
