Answer:

Explanation:
Percent yield is a ratio of the actual yield to the theoretical yield. It is found using this formula:

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.



For this reaction, the percent yield is 60%.
Answer:
As electric current flows through a wire, it generates a magnetic field in the area surrounding the wire.
Explanation:
hope this helps
Answer: The statement (B) is not true about chemical reactions.
Explanation:
A chemical reaction rate is affected by the several factors few of which are temperature, concentration of reactants, surface area etc.
In a chemical reaction, if temperature is increased then the rate of reaction will increase because it will increase the average kinetic energy of the reactant molecules. Thus, large number of molecules will have minimum energy required for an effective collision.
It is known that increasing the amount of reactants will increase the rate of reaction.
Therefore, rate of reaction will change if concentration or temperature is changed.
Hence, the statement (B) is not true about chemical reactions.