Benzophenone reacts with phenylmagnesium bromide in ether solution to make triphenylmethanol after acid workup. Which of the following experimental mistakes will decrease the effectiveness of a Grignard reaction? Select all answers that apply.

a. The magnesium ribbon is insoluble in ether.
b. The glassware was not dried before use.
c. The fume hood was too cold.
d. The magnesium ribbon was not wiped clean before use.

put the answers   and i could answer.

what is the average time it took the car to travel 0.25 meters?

⇒ 2.23 seconds

what is the average time it took the car to travel 0.50 meters?

⇒ 3.13 seconds

a. energy is absorbed in the reaction.

if in a given reaction the energy of products is greater than the energy of reactants it means that reaction is endothermic and during the reaction, the energy is absorbed by reactants. in an endothermic reaction, the products have more stored chemical energy than the reactants. and in this reaction the reactants are more stable than products before the compounds with less energy are always more stable.