Final answer:
To find the final reading in a burette after adding water, multiply the number of drops by the volume of each drop and add this to the initial reading. For 20 drops of 0.4 cm³ each, the total addition is 8 cm³, which gives a final reading of 40 cm³ when added to the initial volume of 32 cm³.
Step-by-step explanation:
To calculate the final reading of water in a burette after adding 20 drops of water each with a volume of 0.4 cm³, we first need to find the total volume of water added. Since there are 20 drops, and each drop is 0.4 cm³, the total volume added is:
20 drops
×
0.4 cm³/drop
=
8 cm³
.
The initial level of water in the burette was 32 cm². To find the final reading, we add the volume of water added to the initial volume:
32 cm²
+
8 cm³
=
40 cm²
.
Therefore, the final reading on the burette would be 40 cm². It's important to note that burettes provide measurements in milliliters (mL), and typically the term cm² is used for area, not volume. Hence, the student might refer to cm³ instead, which is the correct unit for volume. However, assuming the intended unit is volume and not area, the correct final reading, in this case, would be given in cm³ or mL.