Answer:
74.7%
Explanation:
Percent yield is simply a percentage of the recovered substance over theoretical value.
[tex]Percent Yield = \frac{Recovered Product}{Theoretical Amount} * 100[/tex]
recovered substance = 21.2g
Theoretical yield = 28.4g
[tex]Percent Yield = \frac{21.2g}{28.4g} * 100 = 74.7\%[/tex]
This value simply tells you that you only managed to acquire 74.7% of what was theoretically calculated.