Question

For each of the following situations during the density of water experiment, determine if the mistake would give a falsely high or falsely low density for water. For each situation, assume everything else in the experiment is done correctly. Note: It may be helpful to try some hypothetical calculations.

a. When weighing a volumetric flask full of water, a student does not notice that the outside of the flask is wet. ( Choose HIGH,LOW,or Unchanged). Explain Why?

b. When weighing an empty beaker, a student does not notice that there is some water inside. (Choose HIGH,LOW,or Unchanged). Explain Why?

c.  Before placing an empty 10mL graduated cylinder on the balance to get its mass, a student does not notice that the balance reads “-1.4444g.”. When the student weighs the full 10mL graduated cylinder later in the experiment, she correctly sets the balance to “0.0000g.” (Choose HIGH,LOW,or Unchanged). Explain Why?

Answer 1

(a) It will gives more mass which leads to falsely more density.

For example if 1ml water is outside the 1 liter volumetric flask. Now mass is 1.001kg in 1 L. Density= 1.001 g/ml, 0.001 is error

(b) It will gives less mass which leads to falsely low density.

For example if there is 1ml water is inside the beaker ( suppose to be empty). It will deduct in mass of water. For 1 kg water, now it is 0.999 kg in 1liter. Density 0.999g/ml. -0.001 is error.

(c) Student unchanged