Question

Cuvettes should be conditioned before using them. There are two possible errors that can occur if this is not done: a) sample can be poured into a cuvette that has water remaining in it; b) sample can be poured into a cuvette that has leftover dye in it. What effect does each of these errors have on the absorbance measurements in the standard curve? (Write complete sentences that describe each error and its effect.)

Answer 1

Solution:

A) If water is remaining in cuvette:

The absorbance of a sample depends upon the concentration. It is directly proportional to concentration (C).

A = E C l

Thus, the presence of water decreases the concentration and therefore, the measured absorbance is lower than expected.

B) if dye remains in cuvette:

If dye is left in cuvette, then due to color of dye tge sample appears more darker, hence the absorbance will be higher than expected. Thus, the measured absorbance is higher.