Using English to Report :Stoichiometry

Purpose:

The purpose of this lab is to perform the reaction of sodium bicarbonate with sulfuric acid and see how close the actual product yield comes to the theoretical yield.

Summary:

Successfully balancing the equation, figuring out the theoretical and actual yield, solving for the percentage, solving the mean, and solving the standard deviation are the main purpose for this lab. Once each individual grasps the understanding of theoretical and actual yield, each individual will have a better understanding of the reaction of sodium bicarbonate with sulfuric acid.

Procedures:

To first start off, each group had to balance out the equation. It was:

2 NaHCO₃(s) + 1 H₂SO₄(aq) à 2 CO₂(g) + 2 H₂O(l) + 1 Na₂SO₄(aq)

After successfully completing the balanced equation is when each group will start their labs. This lab will be trailed 3 times.

2. Fill a burette no more than half way with 1 M of sulfuric acid (H₂SO₄).

3. Get a clean solo cup with a lid.

4. Measure out approximately 0.200 grams of baking soda (NaHCO₃) into the solo cup.

5. Using stoichiometry, each group then calculates the mass of CO₂ gas. The CO₂ was produced during the reaction above. This number will be the theoretical yield.

6. Before starting the reaction, each group must find the total mass of all the equipment and reactants. This includes the solo cup with baking soda, the lid, and the burette with sulfuric acid.

7. Be sure to push the baking soda to one side of the solo cup before starting the reaction because it will make it react quicker and better later on. Place the lid onto the solo cup before starting the reaction too. The lid is for the purpose of having the sulfuric acid not bubble or splatter onto the table and/or an individual’s skin. Inserting the pipette tip through the hole in the lid and begin adding the sulfuric acid, drop by drop, into the solo cup. (Don’t count the drops). When there is no more bubbling occurring, the reaction is then complete.

8. Now that the reaction is complete, open the lid momentarily to allow the CO₂ gas to escape. Now that everything is mellow, record the total mass after the reaction of all the equipment and left over products.

9. Subtract the total mass after the reaction from the total mass before the reaction to come up with the amount of CO₂ gas that was produced and lost in the air. This is the actual/experimental yield.

10. Rinse and thoroughly dry the solo cup and lid.

11. Repeat all the steps above two more times to make for three trials.

12. Complete all calculations.

Results:

Table 1: Limiting Reagent Amounts

Part A

Mass of NaHCO3	Trial One	Trial Two	Trial Three
	0.200 grams	0.200 grams	0.200 grams

Part B

(This is for our trial one, two, and three. We kept them the same to play it safe.)

0.200 grams NaHCO3	1 mol NaHCO3	2 mol CO2	44.01 grams CO2	0.105 grams CO2 (Theoretical yield)
	84.01 grams NaHCO3	2 mol NaHCO3	1 mol CO2

Table 2: Mass of Reactants and Mass of Products

Part C

	Mass of Reactants Materials	Mass of Product Materials	Difference in Mass Due to Loss of CO2 Gas Produced
Trial One	8.532 + 0.200 = 8.732	22.745 – 13.79 = 8.65	0.072
Trial Two	2.052 + 0.200 = 2.252	15.82 – 13.79 = 2.03	0.222
Trial Three	3.024 + 0.200 = 3.224	16.96 – 13.79 = 3.17	0.054
			This column will be the actual yield

Part D

Trial One

(0.072 / 0.105) x 100 = 68.57 %

Trial Two

(0.222 / 0.105) x 100 = 211.43 %

Trial Three

(0.054 / 0.105) x 100 = 51.43 %

Mean = 110.48 %

 Standard Deviation = 87.85

Commentary: Overall, I had a hard time understanding the concept of this lab, but now after thinking about it and talking amongst classmates I have a better understanding. I believe my group could have done a better job altogether. I believe this because if you look at Part D, our percentages are not close, especially Trial Two. Our Trial Two was so far off because my group didn’t take the time to actually take our time. I also feel as if though we rushed through this lab because we messed up twice in the very beginning of lab time.