Unit 7 Kinetics and Thermodynamics Review

Review

Unit 7 Retake TicketName______

Vocabulary
boiling pointcatalystcondensationdepositionfreezing pointenthalpyevaporationmelting point phases solidification sublimation vaporization heat of fusion heat of vaporization

  1. The process of a liquid becoming a gas is called ______.
  2. The process of a solid becoming a gas is called ______.
  3. Gas, Liquid, and solid are the three ______of matter.
  4. The amount of heat energy required to melt one gram of a solid is the ______
  5. The process of a solid becoming a liquid is called ______.
  6. The temperature at which a liquid becomes a gas is its ______.
  7. The amount of heat energy needed to boil one gram of liquid is the ______
  8. The process of a gas becoming a solid is called ______.
  9. The temperature at which a liquid becomes a solid is its ______.
  10. The process of a gas becoming a liquid is called ______.
  11. The process of a liquid becoming a gas at its boiling point is called ______.
  12. The temperature at which a solid becomes a liquid is its ______.
  13. The ______of ______or ______is used to describe how much energy is produced or used during a chemical change.
  14. The potential energy of a chemical system is called the ______.
  15. A ______is used to lower the energy required to make a reaction take place. It makes chemical reactions go faster without being consumed.

Phase Diagrams(solid, liquid, gas, energy, equilibrium, triple point, critical point, melting point, boiling point, sublimation)

______is a dynamic condition in which two opposing changes occur at equal rates in a closed system.

Change in the state of matter always involves a change in ______.

A phase diagram is a graph of pressure versus temperature that shows the conditions under which the phases of a substance exist.

The ______of a substance indicates the temperature and pressure at which all three phases coexists at equilibrium.

  1. The AB line is the ______&______interface.
  2. It starts at the ______(A), the point at which all three states are in equilibrium.
  3. Each point along this line is the ______of the substance at that pressure.
  4. The AD line is the interface between ______.
  5. The ______at each pressure can be found along this line.
  6. Below A the substance cannot exist in the ______phase.
  7. How could you change directly from a solid to a liquid at F?
  1. How could you change directly from solid to a gas at E?
  1. How could you change directly from a gas to a liquid at G?
  1. How could you change directly from a gas to a solid at G?
  1. What is the process of crossing the AB line from E called?

Energy Change in Chemical Reactions

  1. How much heat will be transferred when 5.81g of graphite reacts with excess H2 according to the following equation? Is the reaction endothermic or exothermic? 6C+ 3H2 → C6H6 ∆Ho = 49.03kJ

Ans: 3.95 kJ

  1. What is the change in enthalpy when 11.8g of iron reacts with excess O2 according to the following equation? Is the reaction endothermic or exothermic? 3Fe + 2O2 → Fe3O4 ∆Ho = -1120.48kJ

Ans: -78.9 kJ

Energy Conversions: 1 calorie = 4.184J, 1 Calorie (food) = 1 kilocalorie = 1000 calories, 1 KJ = 1000 J

450 Calories = ? joules (A: 1,900,000J)

4900 calories = ? KJ (A: 21KJ)

Calorimetry

Brinkmann2011

Unit 7 Kinetics and Thermodynamics Review

Review

Measuring heat (formerly measured in calories) is called ______. In the metric system, heat energy is measured in in ______(J). The equation we use is:

  1. How much heat energy is needed to raise the temperature of a 55 g sample of aluminum from –24 °C to 94.6 °C? (A: 5800J)
  1. 5.5 KJ of heat are added to an unknown 25 grams sample. The temperature of the water is raised from 25K to 269 K. What is the specific heat? What is the unknown substance? (A: 0.89J/gC)
  1. 3.5 KJ of heat are added to a 28.2 g sample of copper at 20°C. How much did the temperature rise? (A: 3200C)

/
  1. Which part of the graph corresponds to each of the following?
  1. Gas(steam) ___ l. Q = mCT ______
  2. Liquid ___ m. Q = mHf ___
  3. Solid(ice) ___ n. Q = mHv ___
  4. Melting ___ o. C = 4.184J/gC
  5. Boiling ___ p. C = 2.02J/gC
  6. Condensing ___ q. C = 2.11J/gC
  7. Freezing ___
  8. Heat of fusion ___
  9. Heat of vaporization ___
  10. Change in PE (2) ______
  11. Change in KE ______

  1. How much heat is necessary to change a 52.0 g sample of steam at125.0 °C into ice at -50.0 °C? This problem requires several steps since temperature changes and a phase change takes place. Use the hints to solve.
  1. Draw a graph of the change in temperature.
  1. Calculate heat change to cool steam down. (A: 2630J)
  1. Calculate heat change during vapor condensation: (A: 118,000J)
  1. Calculate heat change as water cools: (A: 21,800J)
  1. Calculate heat change during freezing: (A: (17,400J)
  1. Calculate heat change for cooling of ice (A: 5490J)
  1. Calculate the total energy change (A: add em all up!) (exothermic or endothermic?).

Brinkmann2011

Unit 7 Kinetics and Thermodynamics Review

Review

Energy Diagrams

The heat content of the reactants of the forward reaction is about kilojoules.
2. The heat content of the products of the forward reaction is about kilojoules.
3. The heat content of the activated complex of the forward reaction is about kilojoules.
4. The activation energy of the forward reaction is about kilojoules.
5. The heat of reaction (H) of the forward reaction is about kilojoules.
6. The forward reaction is (endothermic or exothermic).
7. The heat content of the reactants of the reverse reaction is about kilojoules.
8. The heat content of the products of the reverse reaction is about kilojoules.
9. The heat content of the activated complex of the reverse reaction is about kilojoules.
10. The activation energy of the reverse reaction is about kilojoules.
11. The heat of reaction (H) of the reverse reaction is about kilojoules.
12. The reverse reaction is (endothermic or exothermic).

(Check your answers at

  1. Draw the activation energy curve if the reaction above is catalyzed. Estimate the catalyzed activation energy.______

Collision Theory (Page 732 – 737)

C6H12O6 (s) + 6 O2(g) 6 H2O (g) + 6 CO2 (g)
  1. What happens to the concentrations of:
  1. C6H12O6 & O2 as the reaction proceeds?
  2. H2O + CO2 as the reaction proceeds?
  1. According to the collision theory, what 3 circumstances are needed for C6H12O6 & O2 to react?

3. What is the activation energy for a chemical reaction?

Use the collision theory to explain the following: (Page 738-743)

Change in condition / Increases/Decreases / Explain why.
a. Increasing the temperature / Ex: Increases (speeds up) / Ex: Molecules move faster; more molecules collide with greater energy; activation energy
c. Decreasing the concentration of O2
d. Increase the surface area by turning the sugar from granular to powdered
e. Decreasing the temperature
j. Using a catalyst (like salivary amylase)

Rate of Reaction

  1. A pieces of magnesium reacts with 10 ml of 1 M hydrochloric acid. What is the rate of the reaction? Assume the magnesium is 0.15 grams.
  2. Calculate the overall rate of the reaction. (A: 0.23C/sec)
  1. Is this reaction endothermic or exothermic?
  1. In the gas-phase reaction I2 + Cl2→2Cl, the [I2] changes from 0.400 M at time= 0 to 0.300 M at time = 4 .00 min. Calculate the average reaction rate inmoles I2 consumed per liter per minute. (A: -0.025M/min)
  1. Given the following data for the decomposition of hydrogen peroxide, calculate the average reaction rate in moles H2O2 consumed per liter per minute. (A: -0.075M/min)

Time (min) / Concentration H2O2 (M)
0 / 2.5
2 / 2.12
5 / 1.82
10 / 1.48
20 / 1.0

Chemistry 1-2 Brinkmann