[Princess_Sakura93]

I'm really desperate for help with something for my Chem. lab tomorrow. I pretty much tried every other site on help with this, except for Soompi. OTL.

We're supposed to determine the percent composition of a sand/salt mixture (mass/mass). We have to to come up with our own procedures for this, and I'm stuck on how to do this. D: My teacher gave us a sheet with the list of materials we're allowed to use and some useful pieces of information that will help us somehow.

Materials
-Beakers, graduated cylinder, balance, filter paper and funnel, rinse bottle, test tube and rack, stirring rod, silver nitrate solution, sodium chloride solution, hot plate, ring stand, sample and spatula.

Useful Information
-NaCl will dissolve in water, and the solution will pass through filter paper.
-Sand is insoluble and sand will be retained by the filter paper.
-Any remaining salt should be rinsed off from the sand.
-Silver nitrate is a positive test for NaCl in solution.
-You start off with (weigh out) a dry sample, you should get the dry weight at the end of the experiment.

I tried brainstorming ideas for the procedure with the other two members of my group, but we didn't have enough time to finish our procedure. And we're not even sure if our procedure is right. >___< I'd appreciate any help I can get with this.

...I hope I posted this in the right section. :x

[maychaioo]

What is the procedure you brainstormed? What is it you have to do exactly?

[josebiwasabi]

the "useful information" just outlined the procedure for you. i don't understand your question.

[maychaioo]

what is it you have to do? do you start out with weight out salt and weight out sand? then do you mix the two together then separate it?

[Princess_Sakura93]

maychaioo - We didn't come up with a whole procedure since we didn't have enough time. But what we came up with was basically measure 5 grams of NaCl, pour the 5 grams of NaCl into a beaker, fill the beaker with water (enough to dissolve the salt), put in the sand, stir the solution with a stirring rod, filter the solution using the filter paper and funnel, pour the sand into a test tube, test for any NaCl in the sand, rinse the sand to get rid of any remaining NaCl, filter that solution, then heat the NaCl solution using the hot plate. (The teacher mentioned something about using the hot plate.) That's all we got up to. I'm sure we're missing a lot of things though.

We have to find the percent composition of the mixture.

josebiwasabi - ...Whoa. Didn't notice that. o_____o;; I gotta read stuff more carefully from now on. OTL. The last piece of info is confusing me though. I'm not sure what it means by the dry weight or how to get the dry weight.

[maychaioo]

i think the dry weight is just the 5 gms of nacl and 5 gms of salt. if everything works to plan your start weight of nacl and the start weight of sand should be the same as the end weight

[f0reveralways]

i googled it.

http://web.cocc.edu/zziegler/G_CHEM_fall/L...composition.pdf


is that what you are doing?

[Princess_Sakura93]

maychaioo - Ahhhhh. I get it now! That makes sense. x3 Thanks for the help! It's really appreciated. (:

f0reveralways - That is EXACTLY what we're doing. xDDD It's just the procedure, but yeah, we're basically doing that. Thank you so much!