Question

When 3.25 grams of Magnesium was mixed in a test tube with hydrochloric acid, and placed in a calorimeter, the temperature of the water increased by 15.4 degrees. Based on this information, what type of reaction occurred, and in which direction did the heat transfer?

A) An endothermic reaction took place, and the heat transferred from the test tube to the water.

B) An exothermic reaction took place, and the heat transferred from the test tube to the water.

C) An endothermic reaction took place, and the heat transferred from the water to the test tube.

D) An exothermic reaction took place, and the heat transferred from the water to the test tube.

Answer: B) An exothermic reaction took place, and the heat transferred from the test tube to the water.

Answer 1

An exothermic reaction occurred when Magnesium reacted with hydrochloric acid, causing heat to transfer from the test tube to the water in the calorimeter.

Step-by-step explanation:

When 3.25 grams of Magnesium is reacted with hydrochloric acid in a calorimeter and the temperature of the water increases, this indicates an exothermic reaction. Heat transfer occurs from the test tube to the water, showing that energy is released by the chemical reaction and absorbed by the surrounding water. Since the temperature of the calorimeter increased, we can understand that heat was not absorbed into the system (Magnesium and hydrochloric acid mixture), but rather released into the surroundings (the water in the calorimeter).