You start with 100mL of 14M HNO3 and 10grams of copper metal. How many moles of the nitrogen dioxide gas will be produced?

0.316 moles are produced.

Explanation:

We state the redox reaction:

4HNO₃   + Cu   →  Cu(NO₃)₂ + 2NO₂ + 2H₂O

We need to determine the limting reactant:

0.1 L . 14 M = 1.4 moles

10 g . 1mol/ 63.54g =0.158 mol

Cu is the limiting reactant. Let's see

4 moles of acid need 1 mol of Cu to react

1.4 moles of acid may react to (4 . 1) / 1.4 = 0.35 moles

We do not have enough Cu.

1 mol of Cu can produce 1 mol of NO₂

Then 0.158 moles will produce, 0.316 moles. (double of moles)

If we see stoichiometry, ratio is 1:2

trigonal pyramidal

tetrahedral

trigonal planar

bent