U N I T T E S T P R A C T I C E

Transcription

1 South Pasadena Honors Chemistry Name 6 Compounds Period Date U N I T T E S T P R A C T I C E Section 1: Multiple Choice. Select the best answer choice for each question. (1 point each) 1. Bonds between which of the following pairs of elements can be considered polar covalent? (A) C P (B) H Cl (C) Mg N (D) O F 7. Metal X combines with chlorine to form XCl 2. What compound does it form with sulfate? (A) XSO 4 (B) X 2SO 4 (C) X(SO 4) 2 (D) X 2(SO 4) 2 2. How many electron(s) is/are transferred when aluminum forms an ionic bond with phosphorous? (A) 0 (B) 1 (C) 2 (D) 3 3. When Ca is bonded with O, (A) Ca and O are in a sea of electrons. (B) Ca and O share two electrons. (C) Ca gains two electrons, while O loses two electrons. (D) Ca loses two electrons, while O gains two electrons. 4. Organic compounds typically: (A) Have only non-metal elements. (B) Start with a metal. (C) Start with carbon and hydrogen. (D) Start with hydrogen. 5. Which of the following compounds is ionic? (A) (CH 3O) 3P (B) H 3PO 3 (C) K 3PO 4 (D) P 4O Which of the following compounds is formed when stannic and oxide ions combine? (A) Sn 2O 4 (B) Sn 4O 2 (C) SnO (D) SnO 2 8. Which of the following is the correct name for AuCl 3? (A) Gold chloride (B) Gold trichloride (C) Gold(III) chloride (D) Gold(III) trichloride 9. Which one of the following is the correct formula for aluminum oxide? (A) Al 2O 3 (B) Al 3O 2 (C) Al 6O 6 (D) AlO 10. What is the name of the compound CF 4? (A) carbon difluorate (B) carbon tetrafluoride (C) fluorocarbonate (D) tricarbofluoride 11. What is the name of the acid, HNO 3? (A) hydronitrate acid (B) hydronitric acid (C) nitric acid (D) nitrous acid 12. Hypochlorous acid refers to: (A) HCl (B) HClO (C) HClO 2 (D) HClO 3

2 13. What is the molar mass of magnesium carbonate, MgCO 3? (A) 56.1 g/mol (B) 68.1 g/mol (C) 84.4 g/mol (D) 312 g/mol 14. What is the molar mass of the sodium hexahydroxystannate ion, Na 4[Sn(OH) 6]? (A) g/mol (B) g/mol (C) g/mol (D) g/mol 15. Calculate the percent oxygen in aluminum hydroxide, Al(OH) 3. [Al = 26.98, O = 16.00, H = 1.008] (A) 12.1% (B) 20.5% (C) 34.8% (D) 61.5% 16. The molar mass of aluminum sulfate, Al 2(SO 4) 3, is 342 g. How many moles of the compound are represented by 285 grams? (A) moles (B) moles (C) 1.20 moles (D) 2.40 moles 17. Milk of magnesia contains the chemical, magnesium hydroxide, Mg(OH) 2. If a bottle contains 35.0 g of Mg(OH) 2, how many molecules does it contain? [molar mass of Mg(OH) 2 is 58.3 g/mol] (A) (B) (C) (D) Which of the following is the correct balanced equation for the decomposition of cupric oxide? (A) 2 Cu 2O (s) 4 Cu (s) + O 2 (g) (B) 2 CuO (s) 2 Cu (s) + O 2 (g) (C) CuO (s) Cu (s) + O (g) (D) CuO 2 (s) Cu (s) + O 2 (g) 19. An oxide of manganese contains 30.4% oxygen by mass. What is the chemical formula of the compound? (A) MnO (B) MnO 2 (C) Mn 2O 3 (D) Mn 2O Which of these correctly pairs the empirical and molecular formulas of a compound? (A) C 3H 6 C 3H 8 (B) CH 2 C 4H 8 (C) NO 2 CS 2 (D) P 2I 4 N 2O 4

3 Section 4: Free Response. Show all your work, including listing the appropriate variables, the correct substitution of the formulas, and the final answer with the correct units to receive full credit. 21. Draw the Lewis Structures for the following: (3 points) Ca atom O atom CaO compound 22. Fill the table by classifying the compound and identify the bond. (6 points) Classify the Compound Identify the type of Bond Compound [ Ionic Compound Covalent Compound Bond [Ionic Bond Nonpolar Covalent Bond Organic Compound Acid] Polar Covalent Bond Metallic Bond] (a) C 2H 6OH OH (b) Cu 2O (c) N 2O 4 CuO NO 23. For each compound, identify whether it s an ionic compound, a covalent compound, or an acid. Then write the name or formula of the compound. (6 points) Name Formula I/C/A (a) K 3PO 4 (b) Ferric carbonate (c) HBrO 4 (d) Iodine heptachloride (e) CrO 3 (f) Nitrous acid 24. Consider the compound trinitrotoluene, C 7H 5(NO 2) 3. [This is TNT.] (a) What kind of compound is C 7H 5(NO 2) 3 (i.e. acid, covalent, ionic, or organic)? Briefly explain why. (2 pts) (b) What is the molar mass of C 7H 5(NO 2) 3? (2 pts)

4 (c) What is the percent composition of nitrogen in C 7H 5(NO 2) 3? (2 pts) (d) How many molecules are in g of C 7H 5(NO 2) 3? (4 pts) 25. A sample of an oxide of iron (Fe xo y) was heated in a crucible. The following masses were recorded. Mass of crucible: g Initial mass of crucible and solid: g Final mass of crucible and solid: g Assume that oxygen was completely vaporized. (a) Calculate the masses of iron and oxygen in the original sample. (4 pts) (b) Find the empirical formula for the compound. (4 pts) (c) If the molar mass of the compound is around 160 g/mol, find the molecular formula for the compound. (4 pts) (d) Write the balanced equation for the decomposition of the compound. (2 pts)

5 Ions List Acetate C 2H 3O 2 or Hydrogen sulfate, HSO 4 Oxide O 2 CH 3COO bisulfate Aluminum Al 3+ Hydronium H 3O + Perbromate BrO 4 Ammonium NH 4 + Hydroxide OH Perchlorate ClO 4 Barium Ba 2+ Hypobromite BrO or Periodate IO 4 OBr Bromate BrO 3 Hypochlorite ClO or OCl Permanganate MnO 4 Bromide Br Hypoiodite IO or OI Peroxide 2 O 2 Bromite BrO 2 Iodate IO 3 Phosphate PO 4 3 Calcium Ca 2+ Iodide I Phosphite PO 3 3 Carbonate CO 3 2 Iodite IO 2 Potassium K + Chlorate ClO 3 Iron (II), ferrous Fe 2+ Silver Ag + Chloride Cl Iron (III), ferric Fe 3+ Sodium Na + Chlorite ClO 2 Lead (II), plumbous Pb 2+ Strontium Sr 2+ Chromate CrO 4 2 Lead (IV), plumbic Pb 4+ Sulfate SO 4 2 Copper (I), cuprous Cu + Lithium Li + Sulfide S 2 Copper (II), cupric Cu 2+ Magnesium Mg 2+ Sulfite SO 3 2 Cyanide CN Mercury (I), mercurous Hg 2 2+ Thiocyanate SCN Dichromate Cr 2O 7 2 Mercury (II), mercuric Hg 2+ Thiosulfate S 2O 3 2 Fluoride F Nickel Ni 2+ Tin (II), stannous Sn 2+ Hydrogen H + Nitrate NO 3 Tin (IV), stannic Sn 4+ Hydrogen carbonate, bicarbonate HCO 3 Nitrite NO 2 Zinc Zn 2+ Answers 1. B 2. D 3. D 4. C 5. C 6. D 7. A 8. C 9. A 10. B 11. C 12. B 13. C 14. B 15. D 16. B 17. B 18. B 19. C 20. B 2+ Ca O Ca O (a) (b) (c) 22. (a) Organic Compound; Polar Covalent Bond (b) Ionic Compound; Ionic Bond (c) Covalent Compound; Nonpolar Covalent Bond 23. (a) potassium phosphate (b) Fe 2(CO 3) 3 (c) perbromic acid (d) ICl 7 (e) chromium(vi) oxide (f) HNO (a) Organic (b) g/mol (c) 18.50% (d) molecules 25. (a) g Fe, g O (b) Fe 2O 3 (c) Fe 2O 3 (d) 2 Fe 2O 3 (s) 4 Fe (s) + 3 O 2 (g)