States of Matter Chapter 10 Assignment & Problem Set

Transcription

1 States of Matter Name Warm-Ups (Show your work for credit) Date 1. Date 2. Date 3. Date 4. Date 5. Date 6. Date 7. Date 8.

2 States of Matter 2 Study Guide: Things You Must Know Vocabulary (know the definition and what it means): state of matter solid, liquid, gas molecular attractions (intermolecular forces) dispersion force dipole-dipole force hydrogen bonding force polar & non-polar molecules Kinetic Molecular Theory (KMT) pressure atmospheric pressure vacuum average kinetic energy kinetic energy distribution condensed matter evaporation dynamic equilibrium vapor pressure boiling point normal boiling point crystal lattice allotrope amorphous phase diagram triple point sublimation Learning Objectives: how distinguish solids, liquids, and gases based on: a. definite or indefinite volume and shape of the substance b. how the molecules are arranged. the two primary factors that determine whether a substance is solid, liquid, or gas are kinetic energy (measured by Kelvin temperature) and molecular attractions (dependent on the substance). the three types of molecular attractions, and what each type means. the strength of the dispersion force depends on molar mass. all molecules have the dispersion force. how to tell whether a molecule is polar or non-polar by drawing the electron dot structure and determining molecular symmetry. how to determine whether a molecular substance can have the hydrogen bonding force based on its structure. the statements (or assumptions) that make up Kinetic Molecular Theory. what pressure is. how to convert units of pressure (atmospheres, mm Hg, pascals). Kelvin temperature is a measure of average kinetic energy the molecules of a substances at a given Kelvin temperature have a range of kinetic energies given by the kinetic energy distribution. how evaporation of a liquid can occur below its boiling point. what is meant by vapor pressure how to determine the vapor pressure of the four substances on Table H. what happens to molecules during boiling, and how to determine boiling point as a function of pressure using Table H. boiling/condensing and melting/freezing are examples of dynamic equilibrium. the definition and examples of allotropes. the definition and examples of amorphous solids the definition and examples of sublimation. Key Reference Tables Table A: Standard Temperature and Pressure Table H: Vapor Pressure of Four Liquids

3 States of Matter 3 Read Chapter 10: States of Matter, and Chapter 16 section 16.3 No lab Regents Tables : Table A: Standard Temperature & Pressure Table H: Vapor Pressure of Four Liquids Table T : Important Formulas and Equations Warm-ups and problems will be collected before you take the test. Answer all problems in the space provided. For problems involving an equation, carry out the following steps: 1. Write the equation. 2. Substitute numbers and units. 3. Show the final answer with units. There is no credit without showing work. Molecular Attractions 1. Describe the three kinds of attractive forces that hold groups of molecules together. Rank these forces from weakest to strongest. 2. Why do compounds with strong intermolecular attractive forces have higher boiling points than compounds with weak intermolecular attractive forces? 3. Name three properties of molecular substances that depend on the strength of molecular attractions. 4. Draw electron dot structures of each molecule and state whether each is polar or nonpolar. a. CCl 4 b. HF c. SO 3 d. NH 3 e. CO 2 5. Depict the hydrogen bonding between two ammonia molecules. 6. Which compound in each pair exhibits hydrogen bonding? a. H 2S, H 2O b. HCl, HF c. HBr, HCl d. NH 3, H 2O

4 States of Matter 4 Kinetic Molecular Theory 6. Briefly state the assumptions of KMT. 7. What is meant by elastic collisions? 8. What is significant about the temperature absolute zero? 9. Use kinetic theory to explain what causes gas pressure. 10. What is STP in Kelvins and kpa? 11. Express the pressure 545 mm Hg in kilopascals. 12. Change 1656 kpa to atm. 13. Convert 190 mmhg to the following: a. kilopascals b. atmospheres of pressure 14. A cylinder of oxygen gas is cooled from 300 K (27 o C ) to 150 K (-123 o C ). By what factor does the average kinetic energy of the oxygen molecules in the cylinder decrease? 15. What is meant by the kinetic energy distribution of a substance.

5 States of Matter 5 Liquids 16. Use kinetic theory to explain the differences between the particles in a gas and those in a liquid. 17. Why does evaporation lower the temperature of a liquid? 18. Explain dynamic equilibrium of a liquid in a closed container. 19. Explain why increasing the temperature of a liquid increases its rate of evaporation. 20. Would you expect an equilibrium vapor pressure to be reached above a liquid in an open container? Explain. 21. What is the vapor pressure of water at 40 o C? 22. What is the significance of the vapor pressure of water at 100 o C? 23. Use the Table H to determine the boiling point of each liquid: a. ethanoic acid at 25 kpa b. water at 120 kpa c. ethanol at one atmosphere d. of the four substances on Table H, which has the greatest molecular attractions (intermolecular forces)? 24. Explain why the boiling point of a liquid varies with atmospheric pressure. 25. At the top of Mount Everest, water boils at only 69 o C. Estimate the atmospheric pressure at the top of this mountain. 26. Any liquid stays at a constant temperature when it is boiling. Explain why at the molecular level. 27. If the volume of the container in which there is a liquid-vapor equilibrium is changed, the vapor pressure is not affected. Why?

6 States of Matter 6 Solids 28. Molecular solids usually have lower melting points than ionic solids. Why? 29. Explain the nature of solids and tell why they differ from liquids. Refer to the organization of particles in you answer. 30. How do allotropes of an element differ? 31. Is the average kinetic energy of the particles in a block of ice at 0 o C the same as or different from the average kinetic energy of the particles in a gas-filled weather balloon at 0 o C? Explain. 32. What is a network solid? Review 33. How many moles is each substance? a. 888g sulfur dioxide b x molecules of ammonia c. 0.47L of carbon dioxide (at STP) 34. Honors What is the density of krypton gas at STP? 35. Honors Hydrogen gas reacts with ethene (C 2H 4) to form ethane (C 2H 6). C 2H 4 + H 2 C 2H 6 What is the limiting reagent when 40.0g C 2H 4 reacts with 3.0g H 2? 36. For the reaction: 2H 2 + O 2 2H 2O How many grams of water can be prepared from 22L O 2 at STP?