In a precipitation reaction (otherwise known as a double replacement or metathesis reaction) the extent to which a precipitate is formed is dependent on the solubility product constant of the precipitate. A species with a large Ksp (highly soluble) may not precipitate until very high concentrations are reached. A species with a low Ksp (mostly insoluble) will precipitate readily. Use the ideas explored in this activity to explain why the formation of a precipitate may increase when non-stoichiometric amounts of reactants are used (one reactant will limit, while the other will be in excess).

the answer is na (sodium)

b. accuracy of the data matters alot more than its number of digits, organization or amount of detail. quantitative observation is more accepted than the qualitative observation.

chemical changes occur when a substance combines with another to form a new substance, called chemical synthesis or, alternatively, chemical decomposition into two or more different substances. these processes are called chemical reactions and, in general, are not reversible except by further chemical reactions. some reactions produce heat and are called exothermic reactions and others may require heat to enable the reaction to occur, which are called endothermic reactions. understanding chemical changes is a major part of the science of chemistry.