Saturday, May 14, 2011

Final Exam Review Question

23)    Percent Yield:
a.     The decomposition of potassium chlorate yields oxygen gas. If the yield is 95%, how many grams of KClO3 are needed to produce 10.0 L of O2?

b. If 5.0 g of H2 are reacted with excess CO, how many grams of CH3OH are produced, based on a yield of 86%?


  1. I see sig fig issues with both parts. For part (a), 40.12 g becomes 40 g, but it should have two sig figs. The answer should be 4.0E1 g. For part (b), the same problem arises. 39.73 g becomes 40 g, but it should also have two sig figs. the answer should be 39 g. Later on in part (b), you mess sig figs up again when you multiply .86 by 40, and then get an answer with two sig figs...

  2. right, behind both the 40's you mentioned there should be a decimal, and that would allow me to have an answer with 2 sig figs at the end

  3. THIS POST WAS DIVINE! however, you were quite blunt in your answer. Try answering a question like you're wooing a sophisticated woman. You must introduce yourself, explain your steps, and so on.