Reactions can have a wide range of yields. they can produce anything from fractions of percents all the way to almost exactly 100%. the reason that they almost never reach 100% is that almost all reactions are reversible, and once a certain concentration of product is reached, the reaction is no longer favorable.

hypothesize a way that you could force a reaction to reach 100%. explain why it would work and why the reverse reaction wouldn’t occur.

Explanation:

Let us proceed with a reaction

                          A(aq)+B(aq) C(aq) + D(g)

 Taking A, B and C are in aqueous solution. D being a gas. The reaction is carried out in a close vessel. As reaction proceeds, A and B react to give C and D. As the concentration of C and D increases, they react to give back A and B. Now suppose the reaction is carried out in a open vessel so that the gas D can escape in the atmosphere. So the gas D is no longer available to react with C. So reverse reaction will not occur. The forward reaction is forced to reach 100 %

Let us take another example.

                           A(aq)+B(aq) C(aq) + D(aq)

Here, D is a volatile liquid. As soon as D is formed, it is removed by distillation. So D is no longer available to react with C. So reverse reaction will not occur. The forward reaction is forced to reach 100 %