Compounds are Classified in Different Ways

Transcription

1 Name: Class: Date: Compounds are Classified in Different Ways Modified True/False Indicate whether the statement is true or false. If false, change the identified word or phrase to make the statement tr ue. 1. Aqueous solutions containing HCl, H 2 SO 4, and CH 3 COOH will each have a ph value higher than that of pure water. 2. Aqueous solutions containing sodium hydroxide and potassium oxide will each have a ph value higher than 7. Multiple Choice Identify the choice that best completes the statement or answers the question. Use the following unbalanced chemical equation to answer the next two questions. A small amount of baking soda and dilute sulfuric acid is placed into a 1.0 L flask, and the following unbalanced reaction occurs: NaHCO 3 (s) + H 2 SO 4 (aq) Na 2 SO 4 (aq) + H 2 O(l) + CO 2 (g) 3. The coefficients that balance the formula equation, in order from left to right, are: a. 1, 2, 1, 2, 1 c. 2, 1, 2, 1, 2 b. 2, 1, 1, 2, 2 d. 1, 2, 2, 1, 1 4. Which of the following arrangements would provide the best data to support the law of conservation of mass for the reaction? a. an open flask c. a closed flask b. an open flask on a digital scale d. a closed flask on a digital scale 5. Consider the following skeleton equation for the production of ammonia. When the equation is balanced, how many atoms of hydrogen appear on each side of the chemical equation? N 2 + H 2 NH 3 a. two c. six b. three d. eight 1

2 Name: Use the following information to answer the next two questions. Methane, a component of natural gas, burns in oxygen gas to produce carbon dioxide and water according to the following diagram: 6. When the formula equation representing the reaction is balanced, the coefficients that appear in the balanced equation, from left to right, are: a. 1, 2, 2, 1 c. 2, 1, 1, 2 b. 2, 1, 2, 1 d. 1, 2, 1, 2 7. A student tests some household vinegar (a solution of acetic acid) using several different indicators. Which of the following represents the results expected for the indicators listed? Phenolphthalein Bromothymol Blue Litmus Methyl Red Indigo Carmine a. pink blue red yellow blue b. colourless blue blue red yellow c. colourless yellow red red blue d. pink yellow blue yellow yellow a. a b. b c. c d. d 8. Which of the following liquids/solutions is most likely to have the highest ph? a. HCl (aq) c. H 2 O (l) b. CH 3 COOH (aq) d. KOH (aq) 9. Which of the following acids has a formula containing only two elements? a. hydroiodic acid c. perchloric acid b. sulfuric acid d. nitrous acid 2

3 Name: 10. Which compounds below could represent the reactants in a neutralization reaction? I. NaOH II. H 3 PO 4 III. NaNO 3 IV. H 2 O a. I. and II. c. II. and III. b. I. and III. d. III. and IV. 11. Oxides produced from which of the following elements contribute to acid precipitation? I. sodium II. sulfur III. nickel IV. nitrogen a. I. and II. only c. I. and III. only b. I., III., and IV. only d. I. and IV. only 12. An organic compound must contain the element: a. nitrogen c. carbon b. hydrogen d. oxygen 13. Which of the following is not composed of organic compounds? a. vegetable oil c. table salt b. gasoline d. candle wax 14. Which of the following data would correctly apply to a concentrated solution of hydrochloric acid? ph Value H + Concentration OH - Concentration Methyl Orange Colour a. low high low red b. low low high red c. high low high yellow d. high high low yellow a. a b. b c. c d. d 3

4 Name: 15. Which of the following sets of indicator and ph data matches the aqueous solution listed? Aqueous Solution ph Value Litmus Colour Methyl Orange Colour Approximate ph Value a. H 2 SO 4 blue yellow 12 b. NaOH red yellow 2 c. H 2 SO 4 red red 2 d. NaOH blue red 12 a. a b. b c. c d. d 16. A solution is found to have an H + ion concentration times lower than that of pure water. Which of the following conclusions would correspond to this observation? a. a basic solution with a ph of 11 c. an acidic solution with a ph of 11 b. an acidic solution with a ph of 3 d. a basic solution with a ph of Which of the following common household solutions is most likely to have the hydroxide ion in its chemical formula? a. milk c. vinegar b. lemon juice d. oven cleaner 18. Which of the following acids have chemical formulas containing the same number of oxygen atoms? I. chloric acid II. sulfurous acid III. phosphoric acid IV. nitrous acid a. I. and II. c. II. and III. b. I. and III. d. II. and IV. 19. When each of the compounds listed below are dissolved in pure water, which of them will change the ph of the water the least? I. KNO 3 II. HNO 3 III. Sr(OH) 2 IV. SrCl 2 a. I. and II. only c. III. and IV. only b. I. and III. only d. I. and IV. only 4

5 Name: 20. Which of the following will produce an acidic solution when added to water? a. SO 2 c. NaCl b. K 2 O d. CaO 21. Which of the following is an organic compound? a. sulfuric acid c. calcium carbonate b. methane d. sodium oxalate Short Answer 22. First, write out the word equation for a neutralization reaction. Then, write out the balanced formula equation for the neutralization that occurs when sulfuric acid reacts with calcium hydroxide. Problem 23. Complete the table below. Chemical Name Chemical Formula H + vs. OH - Bromothymol Blue Colour sodium hydroxide H + < OH - H 3 PO 4 hydrobromic acid Sr(OH) 2 CH 3 COOH 24. Two clear, colourless aqueous solutions appear identical. One is a concentrated solution of HCl, and the other is a concentrated solution of NaOH. Describe three safe methods to distinguish these solutions from each other. (Use no more than one chemical indicator in your answer). A bonus mark will be awarded for answers containing more than three methods. 25. Write balanced formula equations for the following neutralization reactions: a) H 2 SO 4 + Ca(OH) 2? b) H 3 PO 4 + LiOH? c) H 2 CrO 4 + Al(OH) 3? 5

6 Compounds are Classified in Different Ways Answer Section MODIFIED TRUE/FALSE 1. ANS: F Aqueous solutions containing HCl, H 2 SO 4, and CH 3 COOH will each have a ph value lower than that of pure water. PTS: 1 DIF: Average LOC: C2-2, 3, 4 TOP: Acids and Bases KEY: acids ph 2. ANS: T PTS: 1 DIF: Difficult LOC: C2-2, 5 TOP: Acids and Bases KEY: bases ph MSC: H MULTIPLE CHOICE 3. ANS: B PTS: 1 DIF: Average LOC: C4-3 TOP: Chemical Equations KEY: balanced chemical equations 4. ANS: D PTS: 1 DIF: Easy LOC: C4-1 TOP: Chemical Equations KEY: conservation of mass MSC: K 5. ANS: C PTS: 1 DIF: Average LOC: C4-3 TOP: Chemical Equations KEY: balanced chemical equations 6. ANS: D PTS: 1 DIF: Average LOC: C4-2, 3 TOP: Chemical Equations KEY: balanced chemical equations 7. ANS: C PTS: 1 DIF: Average LOC: C2-1 TOP: Acids and Bases KEY: acids bases ph indicators 8. ANS: D PTS: 1 DIF: Average LOC: C2-2, 3 TOP: Acids and Bases KEY: ph acids bases 9. ANS: A PTS: 1 DIF: Average LOC: C2-4 TOP: Acids and Bases KEY: binary acids MSC: K 10. ANS: A PTS: 1 DIF: Average LOC: C2-3, C4-4 TOP: Salts KEY: neutralization 11. ANS: C PTS: 1 DIF: Average LOC: C2-5 TOP: Salts KEY: salts 12. ANS: C PTS: 1 DIF: Easy LOC: C3-1 TOP: Organic Compounds KEY: organic MSC: K 13. ANS: C PTS: 1 DIF: Easy LOC: C3-1 TOP: Organic Compounds KEY: organic MSC: K 1

7 14. ANS: A PTS: 1 DIF: Average LOC: C2-1, 2, 3 TOP: Acids and Bases KEY: acids bases ph 15. ANS: C PTS: 1 DIF: Difficult LOC: C2-1, 3 TOP: Acids and Bases KEY: ph indicators MSC: H 16. ANS: A PTS: 1 DIF: Difficult LOC: C2-2 TOP: Acids and Bases KEY: ph MSC: H 17. ANS: D PTS: 1 DIF: Average LOC: C2-2 TOP: Acids and Bases KEY: bases 18. ANS: A PTS: 1 DIF: Average LOC: C2-4 TOP: Acids and Bases KEY: acids 19. ANS: D PTS: 1 DIF: Difficult LOC: C2-3 TOP: Salts KEY: acids bases salts MSC: H 20. ANS: A PTS: 1 DIF: Average LOC: C2-5 TOP: Salts KEY: salts MSC: K 21. ANS: B PTS: 1 DIF: Average LOC: C3-2, 3 TOP: Organic Compounds KEY: organic SHORT ANSWER 22. ANS: The word equation for a neutralization reaction is: Acid + Base? Salt + Water. The formula equation for the neutralization that occurs when sulfuric acid reacts with calcium hydroxide is: H 2 SO 4 + Ca(OH) 2 CaSO H 2 O. PTS: 4 DIF: Average LOC: C2-3, C4-3, 4 TOP: Salts KEY: neutralization MSC: H PROBLEM 23. ANS: Chemical Name Chemical Formula H + vs. OH - Bromothymol Blue Colour sodium hydroxide NaOH H + < OH - blue phosphoric acid H 3 PO 4 H + > OH - yellow hydrobromic acid HBr H + > OH - yellow strontium hydroxide Sr(OH) 2 H + < OH - blue acetic acid CH 3 COOH H + > OH - yellow PTS: 7 DIF: Difficult LOC: C2-2, 3 TOP: Acids and Bases KEY: acids bases indicators MSC: H 2

8 24. ANS: The methods that can be used to distinguish the two solutions from each other include the following: (3 Points) i) Test the ph values of both solutions. The ph of the HCl solution will be well below 7, and the ph of the NaOH solution will be well above 7. ii) Add the indicator bromothymol blue to each solution. The HCl solution will be yellow, and the NaOH solution will be deep blue. iii) Into each solution place a small strip of magnesium. The magnesium will react with the HCl solution to produce hydrogen gas but will not react at all with the NaOH solution. Bonus Method: To each solution, add a small amount of baking soda (or carbonate salts). The HCl solution will react to produce carbon dioxide gas, and the NaOH solution will not react at all. (+1 Bonus Point) PTS: 4 DIF: Average LOC: C2-1, 2, 3 TOP: Acids and Bases KEY: acids bases MSC: H 25. ANS: a) H 2 SO 4 + Ca(OH) 2 CaSO H 2 O b) H 3 PO LiOH Li 3 PO H 2 O c) 3 H 2 CrO Al(OH) 3 Al 2 (CrO 4 ) H 2 O PTS: 6 DIF: Difficult LOC: C2-3, C4-4 TOP: Salts KEY: neutralization MSC: H 3