express the law of conservation of matter applying to ammonium chloride, sand, and table salt, help!?

Question

express the law of conservation of matter specifically applying to a mixture of NH4Cl(ammonium chloride) SiO2(sand) NaCl(table salt) being separated

Answer 1

Assume that you are using heat to separate the ammonium chloride, water to separate the salt.

Measure the resulting gas volume of the ammonium chloride.
Measure the solubility of the water.

Answer 2

Do you have more information?

Is there a known amount of each compound?

If we talk about generalities all that I can tell you is that conservation matter tell us that:

Matter that enters to a system = Matter that leaves the system

So , in your case, if you have a mixture of NH4Cl, table salt and sand, we can say that:

mass of mixture = mass of NH4Cl + mass of sand + mass of table salt (after the separation).

It means that if you weight the mixture before and after separation the sum of masses of each component must be equal to the original mass of the mixture.

Good luck!