Aresearcher studying the nutritional value of a new candy places a 3.80 g3.80 g sample of the candy inside a bomb calorimeter and combusts it in excess oxygen. the observed temperature increase is 2.92 ∘c.2.92 ∘c. if the heat capacity of the calorimeter is 41.70 kj⋅k−1,41.70 kj⋅k−1, how many nutritional calories are there per gram of the candy?

Explanation:

The given data is as follows.

         Heat capacity = 41.70 kJ/K,        

Temperature change =

Hence, calculate the quantity of heat as follows.

      Quantity of heat = heat capacity × temp. change

                                  = 41.70 kJ/K × 2.92 K

                                  = 121.764 kJ

This heat energy is related to burning of 3.80 g of given sample.

Therefore, calculate the heat per gram as follows.

                  Heat =

                           = 32.04 kJ/g

As, 1 nutritional calorie = 1000 calorie

      1 calorie = 4.2 J

Therefore, calculate the heat in terms of calorie as follows.

            Heat =

                     = 7.62 calorie

Thus, we can conclude that there are 7.62 calories per gram of the candy.

- "the choice that is not an indicator of a chemical change is "state of matter changes". more common than not, chemical reactions produce energy in the form of light or heat. along with energy, they also produce a new substance called the product that could be in any state of matter (solid, gas, or liquid)."