7) In the diagram below, the left circle represents gaseous carbon and sulfur before they react; the diagram on

the right represents the compound that results when these atoms combine.

BEFORE REACTION

AFTER REACTION

S

S

A) Take an inventory. Count the particles in each diagram and list them in the table below.

Before Reaction

After Reaction

C atoms

S atoms

B) Which reactant (C or S atoms) is in excess?

C) Which reactant (C or S atoms) limits the reaction?

CS₂ molecules

Catoms

• When writing an equation to represent this chemical change, remember, the equation shows how

carbon would combine with sulfur no matter how many total atoms you start with, or what is leftover

(in excess). The left side is what you start with and the right side is the NEW things created.

• Just as you did with the nuts and bolts combination, we want a general statement that tells us how

carbon combines with sulfur.

D) Write a chemical equation to represent how carbon atoms react with sulfur atoms.