A potted plant is placed under a grow lamp, which provides 6,400 J of energy to the plant and the soil over the course of an hour. The specific heat capacity of the soil is about 0.840 J/g°C and the temperature goes up by 9.25°C of soil. How many grams of soil are there?

There are 823.68 grams.

Explanation:

Calorimetry is responsible for measuring the amount of heat generated or lost in certain physical or chemical processes.

Between heat and temperature there is a relationship of direct proportionality. The constant of proportionality depends on the substance that constitutes the body and its mass, and is the product of the specific heat by the mass of the body. In summary, the amount of heat Q that receives or transmits a mass m of a substance with specific heat C to raise its temperature from T1 to T2 is given by the formula:

Q= C*m* (T2- T1) = C*m* ΔT

In this case:

Replacing:

6400J= 0.840 *m* 9.25 C

Solving:

m=823.68 grams

There are 823.68 grams.

your answer is a. the enthalpy of formation for a pure element in its standard state is always positive.