SOLUTION STOICHIOMETRY Lab Report Guideline

The first page must contain the following information. You can use your laboratory data sheet as the first page; it must be fully completed (any missing information will result in a penalty of 0.5 points).

• Name
• Date the experiment was performed
• Lab section
• Balanced chemical equation (including all the state of matter)

DATA AND RESULTS

Laboratory data recorded during the experiment. All information in this table must be written in ink.

SAMPLE CALCULATIONS

Perform all your calculations on the back of the lab data sheet. It must fit in one single page, there is no need to type them and a pencil can be used. Include a short title (one line) before each calculation.
You can even use a "table" calculation format for your calculations, as illustrated on the lab whiteboard (The one you photographed in the lab).

1. Write the balanced chemical equation (with all the state of matter).
2. Identify your limiting reactant (show your calculations).
3. Calculate the theoretical yield and the %yield of the reaction.
4. Calculate the mass of the excess reactant remaining.
5. Calculate the %atom economy.

Calculation in pencil, correct number of significant figures for the final answer only, with units.

If your %yield is less than 80% or over 100%, provide one relevant explanation for your result.

Useful equations

$\mathrm{\%yield}=\frac{\text{actual yield (g)}}{\text{theoretical yield (g)}}\times 100\%$	actual yield = mass obtained in the lab theoretical yield = mass expected or calculated
$\mathrm{\%Atom\; economy}=\frac{\text{mass of the product (g)}}{\text{mass of all the reactants (g)}}\times 100\%$	the masses are based on the stoichiometric reaction not the actual masses obtained in the lab.

LABORATORIES QUESTIONS: Solution Stoichiometry

No need to answer the pre-lab and post-lab questions of the lab manual.
Only answer the following question and submit these with your report on page 2.

Consider the following chemical reaction:

1. For this experiment, 33.01 g of B₂O₃(s) react completely with an excess of sodium hydroxide. Calculate the theoretical yield of Na₃BO₃(s) (in grams) assuming a %yield of 100%. (with the correct number of sig. fig)
   
2. What would be the required mass of B₂O₃(s) to get 50.0 g of Na₃BO₃(s) if the yield of this reaction was 70.88%? Assume the sodium hydroxide to be in excess.

(To get a marks, all your work must be shown)