# Chemistry

posted by .

In a lab we are trying to find the percent yield of NaCl collected after evaporating the water off an NaCl solution. We made up a .100 M NaCl solution, and used 10. mL of it in our experiment.
We know that the empty evaporating dish and cover mass 68.9132 +/- .0003 g, and after our final trial our evaporating dish, cover, and NaCl mass 68.9695 +/- .0003 g.

We calculated our theoretical yield as such..
10. mL +/- .2% x (.100 sub 0 mol +/- .6 % / 1 L) x ( 1 L/ 1000 mL) x (58.77 g / 1 mol) = .058 +/- .001 g

I calculated our actual yeild as such..
68.9695 +/- .0003 g -> 68.9695 +/- .0004 sub 3 %
- 68.9132 +/- .0003 g -> 68.9132 +/- .0004 sub 4%
= .0563 +/- .00008 sub 7 %

Going by these calculations, I calculate the percent yield to be
(.0563 +/- .0008 sub 7 %) / (.058 +/- 1.sub 7 %) = 97 +/- 2 (absolute) %

However, my partner got 97 +/- 3%, and since I haven't done error calculations in a while I'm trusting that her answer is correct. Can someone help me find what I did wrong?

I get one percent error on the measured mass, and two percent on the theoretical.

Stick with your three percent. The precision of the known solutions (molarity and volume) as you have cited is beyond what most college labs do.

## Similar Questions

1. ### Chemistry

In a lab we are doing, we need to find the theoreical amount of NaCl that we should have left after evaporating the water off an NaCl solution. our molarity of the solution was .100 +/- .6%. We made a stock solution of .5836 g of NaCl/ …
2. ### Chem

I am doing a lab concerning pH... Why is it necessary to allow a mixture of 25mL of a 0.1M HCl solution with 20mL of a 0.08M NaOH solution to cool to room temperature?
3. ### chemistry

DATA Empty Evaporating dish and watch glass: 33.6g Evaporating dish, watch glass and NaHCO3: 35.08g Evaporating dish, watch glass and product: 34.65 NaHCO3(s) + HCL (aq) ----> NaCl(s) + H2O(L) + CO2(g) 1. Determine the mass if the …
4. ### Chemistry

I am trying to find the theoretical yield for this lab I am working on. The steps to finidng it would be great. In my lab I took 40mls of H2O + 4g of AgNO3+ 8g of NaCL then I stirred it and filtered in a buchner funnel to be left with …
5. ### Chemistry

A solution is made by dissolving 0.100 mol of NaCl in 5.35 mol of water. What is the mass % of NaCl?
6. ### chemistry

In a laboratory experiment, a 18.0 ml sample of NaCl solution is poured into an evaporating dish with a mass of 24.00 g. The combined mass of the evaporating dish and NaCl solution is 37.15g. After heating, the evaporating dish and …
7. ### chemisrty

Q4) Suppose you prepare 950 mL of a solution by dissolving 100 grams of NaCl in 900 mL of water. Assuming the density of pure water to be 1 g/mL, answer the following questions with regards to this solution: a) What is the mass percent …
8. ### college chemistry

a solution is made by dissolving 25 g NaCl in enough water to make 1.0 L solution. Assume that density of the solution is 1.0 g/mL. calculate the mass percent, molarity, molality, and mole fraction of NaCl.
9. ### chemistry

a solution is made by dissolving 25 g NaCl in enough water to make 1.0 L solution. Assume that density of the solution is 1.0 g/mL. calculate the mass percent, molarity, molality, and mole fraction of NaCl. whats wrong 25 g NaCl 1.0 …
10. ### Chemistry

A saline solution used in intravenous drips for patients who cannot take oral fluids contains 0.92% (w/v) NaCl in water. How many grams of NaCl are contained in 250 mL of this solution?

More Similar Questions