CHEM 1210 Chapter Notes - Chapter 7: Junkers J 1, Joule, Closed System

Which of the following lasers emits photons with the lowest energy? a. an Ar^+ laser with lambda = 514.5 nm b. a He-Ne laser with lambda = 633 nm c. a Kr^+ laser with lambda = 647 nm d. a Nd: YAG laser with lambda = 1064 nm e. an ArF laser with lambda = 193 nm Which of the following statements about energy, systems, and surroundings is NOT true? a. The system can do work on the surroundings. b. The surroundings can provide thermal energy to the system. c. The system can be a chemical reaction that occurs in a sample of matter. d. The system is the part of the universe that is the focus of thermochemical study. e. The surroundings experience the same energy change as the system in order to keep the total energy in the universe constant. Bond length and bond strength are _____ a. arbitrary. b. unrelated. c. directly proportional. d. identical. e. inversely proportional. Which type of bonding involves the sharing of valence electrons by two atoms? a. polar ionic b. metallic c. covalent d. ionic e. intramolecular

Identify the base in the following acid-base reaction. H_2PO^-_4 (aq) + H_2O (l) rightarrow HPO^2-_4 (aq) + H_3O^+ (aq) a. H_2O b. You can't determine without a titration c. H_2PO^-_4 d. H_3O^+ e. This is not an acid-base reaction Which of the following lasers emits photons with the lowest energy? a. an Ar^+ laser with lambda = 514.5 nm b. a He-Ne laser with lambda = 633 nm c. a Kr^+ laser with lambda = 647 nm d. a Nd: YAG laser with lambda = 1064 nm e. an ArF laser with lambda = 193 nm Which of the following statements about energy, systems, and surroundings is NOT true? a. The system can do work on the surroundings. b. The surroundings can provide thermal energy to the system. c. The system can be a chemical reaction that occurs in a sample of matter. d. The system is the part of the universe that is the focus of thermochemical study. The surroundings experience the same energy change as the system in order to keep total energy in the universe constant. Bond length and bond strength are ______ a. arbitrary. b. unrelated. c. inversely proportional. d. identical. e. directly proportional. Which type of bonding involves the sharing of valence electrons by two atoms? a. polar ionic b. metallic c. covalent d. ionic e. intramolecular

3. Explain why it was necessary to create the state function we call entropy. Derive the Second Law of Thermodynahics as part of your explanation. 4. Explain what is meant by each of the following terms: system surroundings universe 5. Model the processes of the melting of ice and the freezing of water in the following manner to show that entropy increases for both of these processes. Set up a simplified model with two systems at different temperatures separated by a heat-conducting wall. The volumes of the systems are constant but not necessarily equal. The two systems are isolated from the surroundings. Derive an equation for the entropy dS of the two systems and use it to show that whether ice melts or water freezes, the entropy will increase 6. Explain why, for a reversible prodess, dSrev-0. 7. Calculate the entropy change for the isothermal, reversible expansion of one mole of an ideal gas from 10.0 L to 22.5L