CHEMISTRY 101 SPRING 2007 EXAM 1 FORM D SECTIONS DR. KEENEY-KENNICUTT PART 1

Transcription

1 NAME CHEMISTRY 101 SPRING 2007 EXAM 1 FORM D SECTIONS DR. KEENEY-KENNICUTT Directions: (1) Put your name on PART 1 and your name and signature on PART 2 of the exam where indicated. (2) Sign the Aggie Code on PART 2 of this exam. (3) Each multiple choice question is actually 2 questions on your scanning sheet. If you are sure of an answer, put the same answer down for both questions for 5 pts. If you cannot decide between two answers, put one answer down for one question and the other answer down for the other question. If you get one correct you'll get half credit for 2.5 pts. If there is an ambiguous multiple choice question, use the last page to explain your answer. (4) Do NOT write on the envelope. (5) When finished, put everything in the envelope and wait to be excused. At the table, take everything out of the envelope. You can pick up the multiple choice part with the answers outside my office 3pm. (6) There are a total of 28 questions (16 actual questions). PART 1 1&2. Of the following name/symbol combinations of elements, which is WRONG? (a) neon/ne (b) gold/au (c) fluorine/fl (d) antimony/sb (e) hydrogen/h 3&4. What is the empirical formula of the sugar, ribose (C 5 H 10 O 5 )? (a) C 5 H 10 O 5 (b) CHO (c) CH 2 O (d) C 2 H 4 O 2 (e) need more information to tell 5&6. Which alkali metal is in the 3th period? (a) na (b) Mg (c) K (d) Ca (e) Rb Keeney-Kennicutt, 2007 D1

2 7&8. Which of the following statements regarding the interpretation of the scattering of alpha particles (helium nuclei) by thin gold foil in Rutherford's laboratory is/are correct? (I) The high velocity alpha particles are scatted primarily by the protons in the gold atom. (II) The gold atom is mostly empty space with a relatively tiny nucleus. (III) Essentially none of the mass but all of the positive charge are contained in the nucleus of the atom. (a) II only (b) III only (c) I and III only (d) I and II only (e) all are correct 9&10. The isotope 32 P contains: (a) 15 neutrons and 17 electrons (b) 15 neutrons and 15 electrons (c) 17 neutrons and 17 electrons (d) 17 neutrons and 15 electrons (e) 17 neutrons and 32 electrons 11&12. Which of the following compounds is a binary covalent compound and whose particle of the compound that has a stable, independent existence is the molecule? (a) nickel(ii) sulfate (b) lithium phosphate (c) sodium nitride (d) ammonium chloride (e) sulfur pentafluoride Keeney-Kennicutt, 2007 D2

3 13&14. Consider the following balanced equation: 2 Fe + 3 Cl 2 2FeCl 3. If 4 moles of Fe are used up, moles of Cl 2 are also consumed. (a) 3 (b) 6 (c) 8 (d) 9 (e) 10 15&16. The imaginary element, Aggium, has the following natural abundances and isotopic masses: Aggium % amu Aggium % amu Aggium % amu Aggium % amu What is the atomic weight of Aggium? (a) amu (b) amu (c) amu (d) amu (e) amu Keeney-Kennicutt, 2007 D3

4 17&18. A certain compound used for fertilizer contains 60.0% oxygen, 5.0% hydrogen and 35.0% nitrogen by mass. Its simplest formula is: (a) NOH 2 (b) N 2 OH 4 (c) N 2 O 3 H 4 (d) NO 2 H 3 (e) N 3 O 2 H 3 19&20.What volume (in liters) of ethanol (C 2 H 5 OH) with specific gravity = 0.80 is required to obtain 640 g of ethanol? (a) L (b) 512 L (c) L (d) 800 L (e) 620 L Keeney-Kennicutt, 2007 D4

5 21&22. What is the percentage of nitrogen in nicotine, C 10 H 14 N 2? (a) 8.64% (b) 9.46% (c) 13.2% (d) 17.3% (e) 21.7% 23&24. A hospital patient is given a solution containing 9.00 x g of iodine-131 (isotopic weight amu). How many atoms of iodine-131 are present? (a) 1.36 x 10 9 (b) 1.36 x 10 8 (c) 4.14 x (d) 4.14 x (e) 6.68 x Keeney-Kennicutt, 2007 D5

6 Keeney-Kennicutt, 2007 D6

7 CHEMISTRY 101 EXAM 1 Form D SPRING 2007 S NAME Signature PART 2 Please read and sign: On my honor, as an Aggie, I have neither given nor received unauthorized aid on this exam. (18 pts) 25. Give the appropriate IUPAC name or formula for the following compounds: (a) sodium nitride (b) (c) chromium(vi) oxide ammonium nitrite (d) phosphorus pentafluoride (e) carbonic acid (f) H 2 SO 3 (g) NO 3 (h) HgCl 2 (i) MgCrO 4 (10 pts) 26. Balance the following equations using whole number coefficients. Identify each species as an atom, a molecule or a formula unit. (a) Mg + O 2 MgO (b) C 6 H 6 + O 2 CO 2 + H 2 O OVER Keeney-Kennicutt, 2007 D7

8 25. Sulfur can exist as S 2 molecules and S 6 molecules. A scientist knows that he has 64 g of sulfur in a container holding only S 3 molecules and 192 g of sulfur in a container holding only S 6 molecules Answer the following questions and show your work to get full credit. (4 pts) (a) Calculate the number of atoms of S in each container? Are they the same. Explain. (4 pts) (b) Calculate the number of molecules in each container. Are they the same in each container? Explain. (4 pts) (c) Draw pictures to defend your results obtained in (b). Keeney-Kennicutt, 2007 D8

9 SCRAP PAPER OR COMMENTS ON EXAM CHEMISTRY 101 EXAM 1 Form D Spring 2007 S NAME Keeney-Kennicutt, 2007 D9