Question

While transferring the weighed salt to the test tube in the experiment, a student accidentally spilled some of their sample. How will this salt loss affect the salt solubilities calculated by the student? Will they be too high, too low, or unaffected? Explain.

Answer 1

Answer:

The spilling of part of the salt by students while measuring the solubility of a salt will make the calculated solubility by the student to be higher than the exact value.

Explanation:

Solubility is the maximum amount in gram or moles of a particular salt that can completely dissolve in a given solvent at a particular temperature. Therefore, in calculation of the solubility is requires three major factors:

1. The amount of salt,

2. The temperature, and

3. The volume of the solvent used.

This experiment and the mistake done by this student only caused an alteration in the amount of salt used while the volume of solvent was held constant. The student would have therefore thought that she/he had added a particular amount of salt; let's say: x moles, which we should assume to be the maximum amount that can be dissolved by the given solvent at that temperature. The spilled salt will generally reduce the moles of the salt that is eventually added by let's say: y moles. Therefore, the actual amount of salt that would have been added will be x - y moles. The solvent will still have room to accommodate more salt since the solubility is constant at this unaltered temperature. The addition of more salt, let"s say: m moles to make up for the loss will make the student record x + m moles of the salt per unit volume of the solvent instead of x - y + m which was eventually added.

Therefore, since the assumed x + m moles will always be higher than the actual x + m - y moles of the salt, the recorded solubility by the student will always be higher than the actual value.