Experiment 2

35

The last calculated result on the report page is the ratio of moles of silver obtained to the

moles of copper wire that reacted. Predict the effect that the following experimental errors

would have on this ratio: would the result appear too high (H), too low (L), or would there be

no effect (N)? Briefly justify your answers. [In this kind of question, you assume you are

unaware that the error occurred.]

a) The silver had not been completely dried.

3.

b) The original mass of the copper wire had mistakenly been recorded too low.

c) Some of the solution spattered out the beaker in step 2.

4. Copper metal is used to precipitate silver ions from solution (by reducing them to silver

metal). Could copper also cause zinc ions to precipitate in this way? (Explain.)

5. A 2.000-g piece of copper wire was used to precipitate silver ions as silver from a solution.

When the copper metal reacts, Cu² ions are formed, which are soluble in water. If 0.750 g of

Ag(s) were produced in this process, what should the final mass of the copper wire be?