Answer:
[tex]\boxed {\boxed {\sf 60 \%}}[/tex]
Explanation:
Percent yield is a ratio of the actual yield to the theoretical yield. It is found using this formula:
[tex]\% \ yield= \frac {actual \ yield}{theoretical \ yield} *100[/tex]
The actual yield is 12 liters, because that was actually produced in the lab.
The theoretical yield is 20 liters, because that was the expected yield.
[tex]\% \ yield= \frac {12 \ L}{20\ L} *100[/tex]
[tex]\% \ yield= 0.6*100[/tex]
[tex]\% \ yield= 60[/tex]
For this reaction, the percent yield is 60%.