Chapter 6

Define potential energy and chemical potential energy.

What is one potential use for substances that have a large amount of chemical potential energy?

Describe what happens when two objects that have different temperatures come into contact with one another.

Distinguish between endothermic and exothermic.

Two different reactions are performed in two identical test tubes. In reaction \(\mathrm{A}\), the test tube becomes very warm as the reaction occurs. In reaction B, the test tube becomes cold. Which reaction is endothermic and which is exothermic? Explain.

What is the sign of \(q\) for an endothermic process? For an exothermic process?

Classify the following as endothermic or exothermic processes. a. Boiling water b. Sweating c. Burning paper d. Water freezing

Convert each value to the indicated units. a. 150. kcal to Cal b. \(355 \mathrm{~J}\) to cal c. \(200 .\) Cal to \(\mathrm{J}\) d. 225 kcal to cal e. \(3450 .\) cal to \(\mathrm{kcal}\) f. \(450 .\) Cal to \(\mathrm{kJ}\) g. \(175 \mathrm{~kJ}\) to cal

A 274 g sample of air is heated with \(2250 \mathrm{~J}\) of heat and its temperature rises by \(8.11^{\circ} \mathrm{C}\). What is the specific heat of air at these conditions?

98.3 J of heat is supplied to \(12.28 \mathrm{~g}\) of a substance, and its temperature rises by \(5.42^{\circ} \mathrm{C}\). What is the specific heat of the substance?