Chemistry Continuing Practice Packet

Transcription

1 Chemistry Continuing Practice Packet Mrs. Andrechek Webberville High School The best way to learn and remember chemistry is to practice. Check out the following apps: - Mahjong Chem - Formulas Lite - Atoms HD - goreact - Nova Elements - Chemistry Check out the following websites: Complete the chemistry tutorials. Continue to practice ACT type questions. Visit the following website for sample questions and tips: Complete the Chemistry Summer Practice packet attached. Chem-is-try!!

2 Chemistry Summer Practice Substances vs. Mixtures A pure substance is matter for which a chemical formula can be written. Elements and compounds are pure substances. Mixtures can be in any proportion, and the parts are not chemically bonded. Classify the following as to whether it is a pure substance or a mixture by writing P or M in the space provided. 1. sodium 2. water 3. soil 4. coffee 5. oxygen 6. alcohol 7. carbon dioxide 8. cake batter 9. air 10. soup 11. iron 12. salt water 13. ice cream 14. nitrogen 15. eggs 16. blood 17. table salt 18. nail polish 19. milk 20. cola Homogeneous vs. Heterogeneous Matter Classify the following as either homogeneous (HOM) or heterogeneous (HET). In a homogeneous mixture you can only see one phase. In a heterogeneous mixture you can see more than one phase. 1. flat soda pop 2. cherry vanilla ice cream 3. salad dressing 4. sugar 5. soil 6. aluminum foil 7. black coffee 8. sugar water 9. city air 10. paint 11. alcohol 12. iron 13. beach sand 14. pure air

3 Physical vs. Chemical Properties A physical property is observed with the senses and can be determined without destroying the object. For example, color, shape, mass, length, density, and odor are all examples of physical properties. A chemical property indicates how a substance reacts with something else. When a chemical property is observed, the original substance is changed into a different substance. For example, the ability of iron to rust is a chemical property. The iron has reacted with oxygen and the original iron metal is gone. It is now iron oxide, a new substance. Classify the following as either a chemical property (C) or a physical property (P). 1. red color 2. reacts with air 3. flammability 4. solubility 5. reacts with acid to form H 2 6. supports combustion 7. bitter taste 8. melting point 9. reacts with H 2 O to form gas 10. density 11. hardness 12. boiling point Physical vs. Chemical Change In a physical change, the original substance still exists, it has only changed form. Energy changes usually do not accompany physical changes, except in phase changes and when substances dissolve. In a chemical change, a new substance is produced. Energy changes always accompany chemical changes. Classify the following as examples of a physical change (P) or a chemical change(c). 1. Sodium hydroxide dissolves in water. 2. HCl acid reacts with NaOH to produce a salt, water and heat. 3. A pellet of sodium is sliced in two. 4. Water is heated and changed to steam. 5. Potassium chlorate decomposes to potassium chloride and oxygen gas. 6. Iron rusts. 7. Ice melts. 8. Acid on limestone produces carbon dioxide gas. 9. Milk sours. 10. Wood rots.

4 Elements and Their Symbols Write the symbols for the following elements. 1. oxygen 2. hydrogen 3. chlorine 4. sodium 5. fluorine 6. carbon 7. helium 8. nitrogen 9. copper 10. sulfur 11. magnesium 12. manganese 13. neon 14. bromine 15. phosphorus 16. silver 17. lead 18. iron 19. calcium 20. potassium Write the name of the element that corresponds to each of the following symbols. 21. Cu 22. K 23. C 24. Au 25. Zn 26. Pb 27. Fe 28. Na 29. S 30. Al 31. Ca 32. Ag 33. P 34. O 35. I 36. Sn 37. H 38. F 39. Ni 40. Hg

5 Parts of an Atom An atom is made up of protons and neutrons which are in the nucleus, and electrons which are in the electron cloud surrounding the atom. The atomic number equals the number of protons. The electrons in a neutral atom equal the number of protons. The mass number equals the sum of the protons and neutrons. The charge indicates the number of electrons that have been lost or gained. A positive charge indicates the number of electrons (which are negatively charged) lost. A negative charge indicates the number of electrons gained. This structure can be written as part of a chemical symbol. mass number 12 atomic number 6 C +4 charge This carbon ion would have 6 protons, 6 neutrons and 2 electrons. Complete the following chart. Element/ Ion 12 C Mg K Na F Al H 1 24 Mg +2 Atomic Mass Charge Protons Neutrons Electrons Number Number Ag S -2 2 H 1 35 Cl -1 Be +2

6 Bohr Models Draw Bohr models of the following atoms. The protons and neutrons are in the nucleus and the electrons are in energy levels surrounding the nucleus H He Li Na Cl Cu Number of Atoms in a Formula Determine the number of atoms in the following chemical formulas. 1. NaCl 2. H 2 SO 4 3. KNO 3 4. CaCl 2 5. C 2 H 6 6. Ba(OH) 2 7. NH 4 Br 8. Ca 3 (PO 4 ) 2 9. Al 2 (SO 4 ) Mg(NO 3 ) Cu(NO 3 ) KMnO H 2 O H 3 PO (NH 4 ) 3 PO Fe 2 O NaC 2 H 3 O Mg(C 2 H 3 O 2 ) Hg 2 Cl K 2 SO 3

7 Types of Chemical Bonds An ionic bond is formed between a metal and a non-metal. A covalent bond is formed between two non-metals). Classify the following compounds as ionic (I) or covalent (C). 1. CaCl 2 2. CO 2 3. H 2 O 4. K 2 O 5. NaF 6. CH 4 7. SO 3 8. LiBr 9. MgO 10. HCl 11. KI 12. NO FeCl P 2 O 5 Writing Binary Formulas Write the formulas for the compounds formed from the following ions. 1. Na +, Cl - 2. Ba +2, F - 3. K +, S Li +, Br - 5. Al +3, I - 6. Zn +2, S Ag +, O Mg +2, P Ni +2, O Ni +3, O Fe +2, O Fe +3, O Cr +2, S Cr +3, S Cu +, Cl Cu +2, Cl Pb +2, O Pb +4, O Mn +2, Br Mn +4, Br -

8 Naming Binary Compounds (Ionic) Name the following ionic compounds. 1. BaCl 2 2. NaF 3. MgS 4. Al 2 O 3 5. CaI 2 6. K 2 S 7. CaO 8. Ba 3 P 2 9. Na 2 O 10. BeS Naming Binary Compounds (Covalent) Name the following compounds using the prefix method. 1. CO 2. CO 2 3. SO 2 4. NO 2 5. N 2 O 6. SO 3 7. CCl 4 8. NO 9. N 2 O P 2 O N 2 O CS OF PCl 3 Writing Formulas from Names Write the formulas for the following compounds. 1. carbon monoxide 2. sodium chloride 3. carbon tetrachloride 4. magnesium bromide 5. aluminum iodide 6. carbon dioxide 7. dinitrogen pentaoxide 8. sulfur trioxide 9. water 10. calcium chloride

9 Balancing Equations Balance the following chemical equations 1. CH 4 + O 2 CO 2 + H 2 O 2. Na + I 2 NaI 3. N 2 + O 2 N 2 O 4. N 2 + H 2 NH 3 5. KI + Cl 2 KCl + I 2 6. KClO 3 KCl + O 2 7. S + O 2 SO 3 8. H 2 O 2 H 2 O + O 2 9. Na + H 2 O NaOH + H C 2 H 6 + O 2 CO 2 + H 2 O Classifying Chemical Reactions Classify the following reactions as synthesis (S), decomposition (D), single displacement (SD) or double displacement (DD). 1. CH 4 + O 2 CO 2 + H 2 O 2. Na + I 2 NaI 3. N 2 + O 2 N 2 O 4. N 2 + H 2 NH 3 5. KI + Cl 2 KCl + I 2 6. KClO 3 KCl + O 2 7. S + O 2 SO 3 8. H 2 O 2 H 2 O + O 2 9. Na + H 2 O NaOH + H C 2 H 6 + O 2 CO 2 + H 2 O

10 Acids and Bases Classify each of the following compounds as an acid, a base or a salt. 1. HNO 3 2. NaOH 3. NaNO 3 4. HCl 5. KCl 6. Ba(OH) 2 7. KOH 8. H 2 SO 4 9. CaCl H 3 PO Mg(OH) H 2 CO NH 4 Cl 14. HBr ph ph is a scale that measures the hydronium ion concentration of a solution. Therefore, the ph scale can be used to determine the acidity of a solution. A ph of less than 7 indicates an acidic solution, a ph of 7 is neutral, and a ph of greater than 7 up to 14 is basic. The lower the ph, the higher the acidity. The higher the ph, the lower the acidity. Indicators are substances that change color at different ph levels. Phenolphthalein is colorless in an acid and a neutral solution, and pink in a base. Blue litmus changes to red in an acid, and remains blue in neutral and basic solutions. Red litmus remains red in acidic and neutral substances, but turns blue in bases. Complete the following chart. ph Acid, base, neutral Phenolphthalein Blue litmus Red litmus

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