PLEASE GET OUT YOUR GREEN PACKET
& RUBRIC & HW SHEET & HIGHLIGHTER
Work Day!
Quest Day!
LIMITING REACTANTS AND PERCENT YIELD
Ex: Sodium sulfate and water are created when 50 g of NaOH and 75 g of H2SO4
are mixed. Calculate the percent yield if only 25 g of sodium sulfate are made.
Steps:
1. Write and balance equation
2. Calculate how much Na2SO4 can be made with 50 g NaOH
3. Calculate how much Na2SO4 can be made with 75 g of H2SO4
The lower # from 2 and 3 is how much Na2SO4 you can make!
1. Percent yield = actual yield (25g)/theoretical yield (answer above) x 100
How much did I actually get/How much should I have gotten?
ANSWERS
1. H2SO4 (aq) + 2NaOH (aq)  Na2SO4 (aq) + 2H2O (l)
2. (50g/40.00/2*140.15)=88.78125 90 g of Na2SO4
3. (75/98.09*140.15)=107.159 110 g of Na2SO4
NaOH is the limiting reagent so I can only make 90 grams of Na2SO4
4.
25 g / 90 g = 27.77777…  30 % yield
DISCUSSION
Do you think that you will have more or less copper than you started with?
Why could a group have less copper?
Why could a group have “more copper”?
HW REVIEW
Review the homework with your lab group. We will check answers as a class in a bit.
Log on homework sheet and total “Unit 6 homework” Out of 40 points & highlight
WORK DAY!
Homework:
Finish PowerPoint
Finish green packet
1. Please retrieve your copper from the hood
2. Weigh your copper and filter paper in the back
3. Calculate the weight of your copper (subtract off your filter paper)
4. Tell the teacher your final mass
5. They will tell you your initial mass
6. Continue working on your PowerPoint!
WORK TIME!
Work on your PowerPoint as a group
Finish your green packet
Last 30 minutes for Quest!
Homework:
Finish powerpoint
Finish green packet
STOICHIOMETRY QUEST
Homework:
Finish PowerPoint
Finish green packet
Exit Task: (when finished with your Quest)
On a piece of paper WITHOUT your name. (or with your name… who cares!)
What words of advice do you have for next year’s
students doing the copper lab?