Question

A. Representative Particle Level Mass-Mass Relationships in a Chemical Reaction Consider the following reaction between sodium metal and solid sulfur: 2 K(s) + S(s) = K2S(s) Two sodium atoms react with one sulfur atom to form one sodium sulfide formula unit.

average mass of a potassium atom = 6.493 x 10^-23 g
average mass of a sulfur atom = 5.324 x 10^-23 g
average mass of a potassium sulfide formula unit= 1.831 x 10^-22 g
Mass relationships between representative particles in reactions can be determined just like mass relationships between single nuts, bolts, or bolt/nut combinations as illustrated on the last sheet.

Solve the following representative particle relationship problems. A solution to the first is provided as an example.

1. About what mass of sulfur atoms is needed to completely react with about 2.5756 x 10^-22g of potassium atoms? Ans. __________

2. About what mass of potassium atoms is needed to react with about 4.259 x 10^-22g of sulfur atoms? Ans. __________

To determine the amount of products and reactants that are produced or needed in a given reaction.

Quantitative relationship between the number of moles of various products and reactants in a chemical reaction. (reaction must be balanced).

3. If about 1.282 x 10^-21g of potassium sulfide formula units are formed, how many grams of sulfur reacted (solve by stoichiometry, rather than percent composition!)? Ans. __________