This depends on the sodium chloride concentration; higher the concentration, higher the density.
A balance is sufficient.
This mass is 58 mg.
A set of Digital scales.
The molecular mass of sodium chloride is 58,44 g.
No Magnesium Sulfate (MgSO4) has a mass of 121, and Sodium Chloride (NaCl) has a mass of 59.
Ammonium Chloride sublimes when heated whereas Barium Sulfate does not. Another method would be to add de-ionized water to the mixture. The solids left over will be the Barium Sulfate whereas the the Ammonium Chloride will be mixed with the de-ionized water. Weigh everything first, including the water because the Ammonium Chloride will sublime when dry if you try to evaporate the de-ionized water from the mixture.
13.5 lbs. per Imperial Gallon / 11.86 lbs per US Gallon.
About 920g is the mass, but the weight is about 9.03N, depending on your location on Earth.
Unless the rock causes some of the water displaced in the tank to overflow and leave the tank, just placing the rock into the water won't change the weights; it will still weigh 100 pounds.
Weigh 1.499gm of pure Sodium Nitrite Standard (Purity>99%) in an A class volumetris flask and dissolve completly in double distilled water up to the mark.
Regular salt is composed of one compound, sodium chloride (NaCl) or if it is iodized salt, it also has a small amount of an iodine compound such as sodium iodide (NaI). Sea salt, which is made through the evaporation of sea water, contains many different kinds of salts.
That would depend on how much you have to weigh.