Why is it important to have stoichiometric equivalent amount of reactants , what will it do for the products?

Using a value of ksp = 1.8 x 10-2 for the reaction pbcl2 pb+2(aq) + 2cl -(aq). if the value of ksp was determined to be only 1.2 x 10-2: too much solid has dissolved. additional precipitate is forming. the solution is unsaturated. the ions are now combining to reduce their concentrations.

At 450 mm hg a gas has a volume of 760 l, what is its volume at standard pressure

To separate a mixture of hard candies nd marbles the most efficient method would be