Name Chemistry 10 Dr. Kline 11 March 2004 Row Seat Lab 8:00 10:30

Transcription

1 Test 1 Name Chemistry 10 Dr. Kline 11 March 2004 Row Seat Lab 8:00 10:30 This test consists of a combination of multiple choice and other questions. There should be a total of 24 questions on six pages; please check to make sure that they are all here. You may use the equation/information sheet and any periodic table provided (page 7). Do not use your own tables, scratch paper or other information. Do not share your calculator. Please turn off all cell phones, pagers and other communication devices; if they make noise, they will be confiscated. Shared calculators will be confiscated. Multiple Choice Questions Each of the following 20 questions is worth three points, for a total of 60 points. Answer each question by circling the letter(s) corresponding to the correct choice(s). Unless it is stated otherwise in a given problem, there is only one correct answer for each question. It is not necessary to show work for these questions; however, you may write on the exam. 1. How many significant figures are in the measurement g? a. 2 b. 3 c. 4 d. 5 e How many pl are in 9.9 µl? a. 9.9 x 10-6 pl b. 9.9 x 10 6 pl c. 9.9 x 10-9 pl d. 9.9 x 10 9 pl e. 9.9 x 10-3 pl f. 9.9 x 10 3 pl 3. What is 456 x 10-7 written in scientific notation? a. 456 x 10-7 b x 10-5 c x 10-9 d x 10-8 e x How many km are in 2.54 cm? a x 10 5 km b x 10-1 km c x 10-5 km d x 10-6 km e x 10 6 km 5. What is the answer to (4.34 x 2.0) 5.40, expressed to the correct number of significant digits? a b. 3.3 c d What is the answer to , expressed to the correct number of significant digits? a b. 130 c d Page 1 of 5 Test 1A Chem 10

2 7. Which of the following is/are chemical properties of propane? More than one answer may be correct. a. It is a gas at room temperature. b. It burns easily, producing carbon dioxide gas and water. c. Its density is lb/ft 3 at 70 F are. 8. The density of liquid hexane is g/ml. The density of liquid benzene is g/ml. Which of the following has the larger volume? a g liquid hexane b g of liquid benzene c. They would have the same volume. d. It is impossible to tell. 9. The specific heat of gold is J/g C. The specific heat of copper is is J/g C. Suppose that you want to increase 10.0 g samples of each metal from 25 C to 75 C. Which metal will require the addition of a greater amount of heat? a. Gold b. Copper c. They would require the same amount of heat. d. It is impossible to tell 10. Suppose that you have samples of gold and copper that have the same weight and are both at 25 C. Equal amount of heat are added to each. Which metal will have the lower final temperature? See question #9 for specific heat data on copper and gold. a. Gold b. Copper c. They would require the same final temperature. d. It is impossible to tell 11. Which of the following corresponds to the largest mass? a. 125 dg b. 75 kg c. 120,500 cg d Mg e. 450 g 12. Which of the following elements would be classified as a transition metal? More than one answer may be correct. a. Zinc b. Tin c. Chromium. 13. Which of the following elements would be classified as a halogen? More than one answer may be correct. a. Barium b. Iodine c. Argine 14. Which of the following elements would you expect to gain electrons when it forms an ion? More than one answer may be correct a. Te b. Mn c. Pb Page 2 of 5 Test 1A Chem 10

3 15. Suppose that the as-yet-to-be-discovered element Piconium exists as two naturally occurring isotopes, one with a mass number of 292 a.m.u. and the other with a mass number of 294 a.m.u., and that the atomic mass of Piconium is a.m.u. Which isotope is present in larger natural abundance? a. Piconium-292 b. Piconium-294 c. They are present in equal amounts. d. It is impossible to tell. 16. Which of the following is true of two isotopes of the same element? More than one answer may be correct. a. Their atoms have different numbers of electrons. b. Their atoms have different numbers of neutrons. c. Their atoms have different atomic numbers. d. None of the above. 17. What is the name of the piece of glassware drawn below? a. Beaker b. Pipet c. Buret d. Graduated Cylinder e. Watch Glass 18. What is the charge on the ion formed from magnesium? a. +1 b. -1 c. +2 d. -2 e Magnesium reacts with oxygen to yield magnesium oxide as the only product. If 4.8 g of magnesium is combined with 3.2 g of oxygen, then how much magnesium oxide will be produced? a. 4.0 g b. 8.0 g c. 1.2 g d. 6.4 g e. 1.6 g 20. Which of the following is a metalloid (semimetal)? More than one answer may be correct. a. Boron b. Antimony c. Zinc Page 3 of 5 Test 1A Chem 10

4 Problems and Questions Each of the following is worth the indicated number of points, for a total of 40 points. Please show work, with units, to receive credit unless instructed otherwise. Also, be sure to provide all of the information requested for each question points Fill in the blanks to complete the following table. # is an abbreviation for Number. It is not necessary to show work for this question. Symbol Atomic # Mass # # of Protons # of Electrons # of Neutrons Charge P Co points Diamonds are traditionally measured in carats. A carat is a unit of weight equal to exactly 200 mg. The Star of Africa diamond is the largest cut diamond in the world and is now among the British Crown Jewels. It weighs carats. What is its weight in ounces to three significant digits? points The density of pure platinum metal is g/cm 3. Convert this density to units of pounds per cubic inch (lb/in 3 ). Express your final answer with the correct number of significant digits points Suppose that 64.2 g of aluminum pellets, originally at 30.3 C, absorb 1.40 kj of heat. What is the final temperature? Page 4 of 5 Test 1A Chem 10

5 TEST #1 Spring 2004 Equation and Information Sheet Conversions 1 pound (lb) = g. 1 ounce (oz) = g. 1 inch (in) = 2.54 cm (exact). 1 foot (ft) = cm. 1 yard (yd) = 3 feet (exact). 1 carat = 200 mg (exact) Specific Heat q = m C T C = J/g C for aluminum C = J/g C for silver Page 5 of 5 Test 1A Chem 10