How is a food calorie different from an energy calorie

Question

Assignment 1

Acids, Bases, Redox, Molarity, titration      

1. Identify each of the following aqueous solutions as strong or weak, and as acid, base, or salt:

substance	strong or weak	acid, base, or salt
(example)  HCl	strong	acid
NaOH
HCH3COO
CaCl2
Sr(OH)2
HClO4

2. Write the balanced molecular equation, the complete ionic equation, and the net ionic equation for the reaction of aqueous nitric acid with solid calcium hydroxide.  Remember to include states.

3. A solution is prepared by dissolving 0.325 g of Mg(NO₃)₂in water to make 150.0 mL of solution.  What is the molarity of the solution?

4. A 25.0 mL sample of acetonitrile, CH₃CN (d = 0.786 _mL^g), is dissolved in enough water to produce 150.0 mL of solution.  What is the molarity of acetonitrile in the solution?

5. Folic acid, C₁₉H₁₉N₇O₆, is important in many biological functions.  What mass of folic acid is needed to prepare exactly 10.00 mL of a 0.250 M C₁₉H₁₉N₇O₆ aqueous solution?

6. A 25.00-mL solution of 0.350 M urea, CO(NH₂)₂, is diluted to 150.00 mL.  What is the new molarity of the solution?

7. What is the oxidation number of the underlined element in:

a. NaOH        c. H2PO₄-

b. Na2CO3    d. Cr2O₇2^-

8. For the following oxidation-reduction reactions, indicate which species are reduced and which are oxidized.  [These redox reactions are not necessarily balanced-and you don't need to balance them-just identify the species reduced and the species oxidized.]

a. Fe(s)  +  Cu²⁺(aq)  →   Fe²⁺(aq)  +  Cu(s)

b. VO2+(aq)  +  MnO₄-(aq)  →  VO₂+(aq)  +  Mn2+(aq)

For problems 9 - 13, balance the given redox reactions in acidic solution.  For problems 12 and 13 balance the redox reactions in basic solution.

9. S(s)  +  OCl-(aq)  →  SO₃2-(aq)  +  Cl-(aq)

10. Fe2+(aq)  +  Cr₂O₇2-(aq)  →  Fe3+(aq)  +  Cr3+(aq)

11. S₂O₃2-(aq)  +  MnO₄-(aq)  →  SO₄2-(aq)  +  Mn2+(aq)

12. Fe(OH)₃(s)  +  OCl-(aq)  →  FeO₄2-(aq)  +  Cl-(aq)

13. ClO₂(aq)  →  ClO₃^-(aq)  +  Cl^-(aq)

Assignment 2

All of the following questions are from Chapter 5:

1. Define each of the following terms:

a. energy 

b. work

c. heat

2. What is kinetic energy, and what is the equation, given in Chapter 5, for kinetic energy?

3. List two different units for energy, give SI units where appropriate.

4. How is a food "Calorie" different from an energy "calorie"?

5. Restate the first law of thermodynamics in your own words.

6. Matching:  Place the letter of the correct definition on the line in front of the given term.

            calorimeter          a. enthalpy change that accompanies a reaction

            endothermic        b. heat capacity of one gram of a substance

            enthalpy             c. E + PV

            enthalpy of reaction                d. portion not singled out for study

            exothermic         e. process in which the system absorbs heat

            Hess's Law         f. work involved in the compression or expansion of gas

            pressure-volume work            g. property of a system determined by specifying the system's condition

            specific heat       h. ?H for the overall reaction = sum of steps

            standard enthalpy change       i. portion singled out for study

            state function     j. enthalpy change when all substances are in their standard states

            surroundings      k. process in which the system loses heat

            system               l. device used to measure heat flow.