Respuesta :
Answer: Option (C) is the correct answer.
Explanation:
A calorimeter is a device with the help of which we can measure the temperature of a chemical reaction.
So, when the student forgets to put lid on calorimeter then heat from the reaction mixture is going into the surroundings. As a result, there will be a decrease in reading of the calorimeter due to the loss of heat from the reaction mixture.
Thus, we can conclude that the most likely error and reason for the given situation is temperature readings will be too low because heat will be absorbed by the air.