possible experimental errors?

Question

if your mass differance for massing salt and water before they are mixed and after they are mixed is a negative outcome what might be some experimental errors not human errors to this lab

Answer 1

It would be the salt or the water (otherwise the scales)

Did you heat the water? (evaporation)
Try spooning salt into a dry container ... was there a cloud of finer salt dust not go in?
Could there have been something foreign in the water that the salt reacted with a bit to give off a vapor? (Would flouride do this?)

on the human error side ... did you calculate the containers you weighed the ingrediants separately with? (ie, had water in a beaker sitting on a dish , then salt poured onto the dish ... you weighed the dish twice)

Answer 2

Did you use the same balance? Did you tare the balance prior to use? Were there drafts on the balance pans? Are the balance pans properly calibrated? How close to the limits of tolerance of your balance are you weighing any of your substances? Are you including the mass of the containers (two) that you measured your salt & water in prior to mixing?

Of course, there could be some human errors as well. Technically speaking, the last question above addresses a human error, but a likely explanation is that you spilled some of your solution, salt, or water.

Answer 3

Hi. Salt dissolves and can give unusual numbers due to this.