Posted by Melissa on Saturday, October 23, 2010 at 10:00am.
I am doing a lab online and have no clue on how to get started with the following questions? Please Help me!
1. Calculate and record the following (in grams):
(a) mass of NaCl by subtraction of other components:
(b) measured mass of NaCl after boiling away water:
2. Calculate the percent difference between the results from the two methods from the following equation:
% difference = (measured mass)  (mass by subtraction) / (mass by subtraction) * 100%
3. Based on your experimental results, which is the preferred method of separation?
4. What is the mass percent of each component in your mixture? To determine the mass percent, divide the mass of the component by the mass of the total 10g sample and multiply that result by 100.
(a) % NH©þCl =
(b) % SiO©ü =
(c) % NaCl =
52.26g for a and 50.040 for b in question one and not sure if it's right??

Chemistry  DrBob222, Saturday, October 23, 2010 at 3:52pm
With no date I don't know how we can help you.

Chemistry  Melissa, Monday, October 25, 2010 at 1:51pm
Calculation of the sodium chloride (NaCl) content and evaporation:
1. The amount of sodium chloride in the original mixture may be determined indirectly by adding the masses of ammonium chloride and sand together and subtracting the sum from the initial sample mass of 10g.
2. Next, we will use an alternative procedure to calculate the mass of the sodium chloride. We will heat the solution, which will cause the water to evaporate and leave only the salt.
3. Begin by placing the beaker with the sodium chloride solution on the Bunsen burner, over a low flame, and bringing the solution to a boil.
4. Make sure that the Data window is still open and click on the beaker. Watch the Data window until all of the water has boiled off, leaving only the solid sodium chloride. Then remove the beaker from the flame.
5. Weigh and record the mass of the beaker with the sodium chloride.
Question #1 :
1. Calculate and record the following (in grams):
(a) mass of NaCl by subtraction of other components:
(b) measured mass of NaCl after boiling away water:
2. Calculate the percent difference between the results from the two methods from the following equation:
% difference = (measured mass)  (mass by subtraction) / (mass by subtraction) * 100%
3. Based on your experimental results, which is the preferred method of separation?
4. What is the mass percent of each component in your mixture? To determine the mass percent, divide the mass of the component by the mass of the total 10g sample and multiply that result by 100.
(a) % NH4Cl =
(b) % SiO2 =
(c) % NaCl =
Answer :
a) mass of NaCl by subtraction of other components: 52.26g
(b) measured mass of NaCl after boiling away water:50.040g
I don't know if this information will help? I need some guidance and don't know if it's a case of plug and chuck. 
Chemistry  4834, Friday, February 20, 2015 at 10:27am
5464