If the crucible wasn't covered with a lid the reactants may have produced a gas that was released into the surroundings, or mass may have been lost in the form of water vapour.
Metals are all in the center of the periodic table and are all made up of metals
So we know the number of moles of each compound. If we need to know the concentration we must know the number of moles that the compounds react with...
Carbonated drinks have the air under pressure so that carbon bubbles are forced into the drink, keeping it carbonated. So when you open a can, the air under pressure in the can comes out of the can at a high speed, making a "whooshing" sound. The gas law that applies to this concept is the Boyle's Law (PV=k or P1V1=P2V2).
It is important to use low flame when evaporating water from a recovered filtrate because then the water and filtrate will not spatter and the filtrate can also be recovered after evaporating water.
If flame is not low then water as well as got spatter so it is important to use low flame so that the water and filtrate will not spatter.
