How do I calculate the mass of zinc and iodine that are consumed to produce zinc iodide?
1 Answer
In a chemical reaction, the mass of a substance that is consumed refers to one or more reactants. In the case of your question, the reactants are zinc and iodine, so you are being asked to determine the mass of zinc and the mass of iodine that were consumed to form zinc iodide. The balanced chemical equation for this synthesis reaction between zinc and iodine is:
In order to determine the mass of zinc consumed (reacted), you must know the mass of iodine that was consumed (reacted), or the mass of zinc iodide that was produced. In order to determine the mass of iodine consumed, you must know the mass of zinc that was consumed, or the mass of zinc iodide produced.
Example 1
How many grams of
Solution
-
Determine moles
#"I"_2"# by dividing the given mass by its molar mass. I prefer to divide by multiplying by the inverse of the molar mass,#"mol/g"# . -
Calculate moles
#"Zn"# by multiplying moles#"I"_2# by the mole ratio between#"I"_2"# and#"Zn"# in the balanced equation, with#"Zn"# in the numerator. -
Determine the mass of the
#"Zn"# required to react with#"12.5 g I"_2"# by multiplying the moles#"Zn"# by it molar mass.
Example 2
How many grams of
Follow the same procedure, substituting