Question

PLEASE HELP ME!?!?






I'm in the middle of a lab and I'm stuck on this question & I'm not looking for just the answer okay. I actually want to understand how to do this....so can anyone please help me or show me the steps on how to solve it.
3. An unknown sample of a mixture of salt and sand weighs 7.52 g before washing with water and 3.45 g after. What is the percent of sand in the sample?

Answer 1

salt is highly soluble in water and sand is not. When you washed it with water you took all the salt with it and were left with only sand.

Answer 2

salt will be dissolved in water and the left over will be sand but there will be good quantity of water that would remain between sand particles, so i think that you would have to evaporate the water that is present in sand by heating or something.....

Answer 3

Ok thank you so much both to the both of you!!!

So since the salt is soluble the percent of sand left is like 53 % ?

Answer 4

sand%=\(\dfrac{3.45 g}{7.52 g}*100\%\)

Answer 5

Okay thank you again!

Answer 6

@aaronq I have another question say I'm trying to determine the percent of NaCl in a mixture how would I find that? Is there like a formula for that or is is possible if you could give me a random example...

Answer 7

Mass of ramekin A 77.1 g
Mass of ramekin + sample B 82.1 g
Mass of sample (Subtract A-B) C -5.0 g
Determining Percent of NaCl in mixture ???
Mass of remekin, and solids (after water washes) D 100.3 g
Mass of NaCl (Subtract D-C) E 105.3 g
Percent of NaCl in unknown (E/C *100) F -2106.0 g
Determining Percent of CaCO3 in mixture: ?????
Mass of dish, lid, and SiO2 (final weighing) G 112.3 g
Mass of CaCO3 ????? H
Percent of CaCO3 in unknown (H/G *100) ?????? I
Determining Percent of SiO2 in mixture: ???????
Mass of SiO2 (Subtract H-G) ??????? J
Percent of SiO2 in unknown ( J/H *100) ???????? K


This is my table and I obviously have a few blank spaces and errors but if you could just help by maybe giving me the equations for determining the percent of ___ in a mixture and telling me if I have any error's so far....

Answer 8

@aaronq can you help me at all ?

Answer 9

i can't at the moment, I'm working on an assignment, myself. sorry :S

Answer 10

Ok I understand

Answer 11

But at a later moment even if at all over the next few days do you think you could help me with it?

Answer 12

i'll come back to this tmrw afternoon

Answer 13

Ok thanks so much! I really appreciate it, honestly!

Answer 14

@aaronq can you help me yet?