Section number. Dr. Rick Fletcher. Exam 1 Chemistry 101 February 17, 2010

Transcription

1 NAME Section number Dr. Rick Fletcher Exam 1 Chemistry 101 February 17, 2010 Clearly print your name in the name section of the Scantron answer sheet. Clearly place your student ID number in the SUBJECT section of the Scantron sheet. Maintain appropriate security over your exam. Do not let others see your answers. There is only one most correct response to each of the multiple choice questions. Choose the best answer. Each of the twenty-five questions is worth 4 points. Since the Scantron sheets will not be returned to you, please work through the entire exam and circle the best answer on this exam. Mark this exam as you work the problems then transfer the responses to the Scantron sheet all at one time. This is the best way to reduce errors. Use pencil on the Scantron sheets and make certain to fully erase any changes you make. Use this exam to check your answers on the key that will be posted online cm = 1 in 454 g = 1 lb 946 ml = 1 qt 5280 ft = 1 mile 16 oz = 1 lb 4 qt = 1 gal heat = (sp. Ht.) X (mass) X ( Temp) T (K) = T ( C) T( F) = (1.8 X T( C)) cal = J

2 1. How many atoms are in one molecule of capsaicin, C 18 H 27 NO 3? A) 49 B) Not enough info C) 4 D) Sitting on a bench top are several samples: lithium metal (d = 0.53 g/ml), gold (d = 19.3 g/ml), aluminum (d = 2.70 g/ml), and lead (d = 11.3 g/ml). If all of the samples have the same volume, which one possesses the greatest mass? A) gold B) aluminum C) lead D) lithium 3. In planning a party, you have $50.00 to purchase the 11.0 kg of beef required to feed everyone. If the cost of beef is $2.49 per pound, how much beef can you purchase? A) 44 kg B) 125 lbs C) 20 kg D) 9.1 kg 4. Which one of the following does not naturally exist as a diatomic molecule? A) fluorine B) helium C) hydrogen D) nitrogen 5. Which of the following depicts the number of subatomic particles in the ion 202 Hg 2+? A) 78 protons, 80 electrons, 158 neutrons B) 202 protons, 200 electrons, 80 neutrons C) 80 protons, 82 electrons, 128 neutrons D) 80 protons, 78 electrons, 122 neutrons 6. The speed of light in a vacuum in about m/sec. This number in scientific notation can be expressed as A) 3.0x10 8 m/sec B) 2.998x10 8 m/sec C) x10 9 m/sec D) Both b and c

3 7. Using the appropriate number of significant figures, calculate the answer to the following mathematical equation; 10 + ( ). A) B) C) 550 D) Given the isotopic notation for tungsten-184 ion ( W ), how many neutrons are present? A) 80 B) 68 C) 110 D) A chemical reaction is carried out such that 233 g of reactants are completely consumed. What is the total mass of the products produced by the reaction? A) Not enough information B) 233 g C) more than 233 g D) less than 233 g 10. How many significant figures does possess? A) 4 B) 1 C) 2 D) The area of the atom that contains the largest mass and is the most dense is called A) the focus. B) the nucleon. C) the centroid. D) the nucleus. 12. When measuring the curb weight of an automobile, which unit of mass would be the most appropriate? A) milligrams B) kiloliters C) grams D) kilograms

4 13. A typical piece of paper has a width, or thickness, of inches. How many pieces of paper would be required to make a book that is 5.64 in. thick (neglecting the front and back cover)? A) 5.64 x 10 2 pages B) 1520 pages C) pages D) pages 14. When white, crystalline sugar is heated, it decomposes into a colorless liquid and a black solid. This evidence suggests that sugar is A) a compound. B) not very dense. C) a mixture. D) an element. 15. A certain atom has a charge of 3 and is composed of 10 electrons and 7 neutrons. How many protons does this atom have in its nucleus? A) 7 B) not enough information C) 17 D) A 25-g sample of zinc absorbs 500 J of energy. If the temperature of the sample increases by 51ºC, what is the specific heat for zinc? A) 0.39 J/gºC B) 250 J/gºC C) J/gºC D) 2.5 J/gºC 17. Which of the following statements, or conclusions, is not a component of Dalton's Atomic Theory? A) Atoms of the same element are identical and have the same properties. B) Matter is composed of small, indivisible particles called atoms. C) Chemical reactions are merely the rearrangement of atoms into different combinations. D) Any two elements will always form the same compound.

5 18. The atomic number of an atom is equal to which one of the following? A) number of protons B) number of nucleons C) number of atoms D) number of electrons 19. The process by which sublimation occurs is referred to as A) ectodermic. B) hydrostatic. C) endothermic. D) exothermic. 20. Which one of the following corresponds to the greatest mass? A) 500 g B) 0.75 lbs C) 6.5x10 5 mg D) 0.75 kg 21. The nucleons located in the nucleus of an atom are a combination of which of the following? A) electrons and neutrons B) protons and alpha particles C) protons and electrons D) neutrons and protons 22. Under standard pressure (1 atmosphere) the normal boiling point of water (H 2 O) is 100ºC. This statement is an example of a A) scientific law. B) reproducible observation. C) hypothesis. D) theory. 23. A textbook has mass of 2.33 lbs. What is the mass of the text in units of milligrams? 1 lb. = 454 g A) 1.06x10 3 mg B) 1.06 mg C) 1.06x10 6 mg D) 5.13 mg

6 24. A substance whose appearance and properties are uniform throughout is classified as A) a compound B) a homogeneous mixture C) an element D) any one of the above 25. The mass number for three isotopes is known to be 126, 130, 128. Which atom has the largest number of protons? A) not enough information B) the 128 atom C) the 126 atom D) the 130 atom 26. Please indicate you are taking Version A of this exam by marking the A response on QUESTION 26 ON THE REVERSE SIDE OF THE SCANTRON SHEET. Failure to do this will invalidate your responses.

7 2010 Spring Hour Exam 1A Answer Key 1. A 2. A 3. D 4. B 5. D 6. B 7. D 8. C 9. B 10. A 11. D 12. D 13. B 14. A 15. D 16. A 17. D 18. A 19. C 20. D 21. D 22. B 23. C 24. D 25. A