Question

if unlimited iron is available to react with 34.0g of copper (II) chloride, how many g of copper metal would be produced?

Answer 1

Here is a worked example, Follow the steps.
http://www.jiskha.com/science/chemistry/stoichiometry.html

Answer 2

how do you know what the actual yield will be?!

Answer 3

The example gives theoretical yield and that's all you can calculate from the data you posted. If you have the percent yield you can determine actual yield by
actual yield = theor yield x (%yield/100) = ??; otherwise, it can be done only by performing the experiment and measuring the actual yield.