The products of the mixed solutions were slowly and hesitantly poured into the funnel, until nothing remained in the beaker diagram 2 10. This number was multiplied by a hundred to determine the percent yield equation 4. A third systematic error may be due to the result of evaporation. Also, do not exceed the capacity of the flask: it can hold a maximum of about 250 mL. The qualitative data include your own impressions and observations about the experiment and may include pictures.
Repeat this process until to successive weighings are no more than 0. The problem has already given you the actual yield of 15 grams. Introduction Determining the Percent Yield of Calcium Carbonate Purpose: To compare the theoretical amount to the actual amount of calcium carbonate and calculate its percent yield in the reaction between solutions of sodium carbonate and calcium chloride. Calcium carbonate is a fairly stable compound, thus, it must mean that more energy goes into this reaction than out to produce the desired results. In many instances, substances had to moved from one container to another, stored, poured, and all these transfers are imperfect. Which chemical is the limiting reactant? The same thing can happen whenever we perform experiments in the chemistry lab to make a compound.
To avoid this, covering the reactant beakers would create an equilibrium, causing the amount of reactant that is evaporating equal to the amount of reactant that is condensing back in figure 1 , or by decreasing the temperature from the thermostat in the room so that the room temperature is below the boiling point of the solutions. To do this, you will need to convert the amount of your limiting reactant into the amount of your final product. Middle The filter paper was measured for mass. Place the filter paper in the funnel, in the ring. The electronic balance could have given us an incorrect amount of mass 3. Use the wash bottle to rinse the remaining precipitate form the beaker into the funnel. Even though 5 mL more water was poured into the beaker to get the excess off of the sides, it was near to impossible to actually get all of the excess off of the sides.
Firstly, because the precipitate was left to dry overnight, it could have accumulated dust, as well as reacted with other particles in the air to increase its weight. Calculate the theoretical yield of the solid precipitate. The quantitative data are the data you were told to collect in the procedure. Calculate a percent difference between the two. However, these calculations are made under ideal conditions. Base d on your yield of calcium carbonate, calculate the mass of calcium present in the original solution. Using a graduated cylinder, 50ml of distilled water was added to each of the beakers 5.
Find the percent yield using the theoretical yield you calculated in the pre-lab questions. The last objective of this experiment is to calculate the percent yield of the product produced. Calculate the percent yield for your experiment. Instead, simply measure out an amount between these extremes and record its exact mass. We first make calculations for how much of a compound we'll end up with.
Using this balanced equation, determine the limiting reactant if 15 grams of calciurm chloride was reacted with 15 grams of potassium carbonate. Write the balanced equation for the reaction. Calculate the theoretical concentration of calcium chloride in the solution that you made up in steps 6 and 7. Using a stirring rod to guide the flow of liquid into the filter as shown in the picture , decant the supernatant the liquid above the settled precipitate into the funnel. We know the actual yield, but we first need to calculate the theoretical yield. However, after you do the experiment you discover that only 6. The mass of calcium carbonate will then be compared with the mass predicted by stoichiometric calculations.
You may find it helpful to use a ruler. Pour the contents of both graduated cylinders into the 250 mL beaker and observe the results. The percent yield was calculated by taking the mass of the. The above reaction will produce a solid precipitate of and an aqueous solution of. Meanwhile, proceed to step 4. In relation to this experiment, the theoretical yield is the calculated mass based on if the result has a percent yield of 100%.
Diagram1 : Fold at the dotted line. You need to design your own data table to capture the data for this part of the lab. Which reactant is in excess? Compare the actual mass with the theoretical mass of precipitate and calculate the percent yield. Once cool in 2 - 3 min , weigh it with the filter paper and calcium carbonate on it. Use your answer from Calculations 1-2 above and stoichiometric principles to determine which chemical was the limiting reactant. Subtract the calculated value from the measured value and divide the result by the calculated value.