Precipitate is washed before estimating it. why?

Question

Precipitate is washed before estimating it. why?

Answer 1

Because,washing removes adsorbed impurities.

Answer 2

If you didn't, you would be including dissolved solids in your final weight.

Answer 3

If you wanted to know how much, say, lettuce weighed (I know it is silly!) would you wash off the dirt? I would because dirt is not lettuce so I wouldn't be getting a good idea of what the lettuce weighed if I didn't clean it first. I just want lettuce. Similarly, your product has other "stuff" in it so if you just plopped that whole thing on the scale (without washing) you would have no idea how much product you got.

Answer 4

To make sure that it's just solids, not aqueous solutions left over from the reactions.