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```									Chem 111 September 6th 2007

Fall 2007

Dr. Vilchiz

Print your name: ____________________________________ I hereby certify that the work on this exam is completely my own. I understand that failure to sign may result in a grade of ZERO in this exam. Signature _________________________ DO NOT BEGIN THIS EXAM UNTIL YOU ARE INSTRUCTED TO DO SO. 1. Read over all instructions within the exam carefully. 2. Show all work for credit. Partial credit may be given for correct work. Answers without supporting calculations are considered incorrect. 3. Include units for all calculations involving units. Be careful to consider significant digits in your answers. 4. There are 8 pages in this exam including this cover page, the equation page behind it, the periodic table, and the table of ions. Make sure you have all pages. Note: Necessary equations and constants along with the periodic table are at the end Find this information NOW, so that you know what you have available to you. Feel free to remove the periodic table and the equation sheet for use during the exam, but staple your exam back together when you turn it in. Good Luck! GRADING

Page 3 4 5 Bonus

Points Available 40 35 30 7 112

Points Earned

/100

Equations and Constants Equations: x·mu≥h/4  ph   finalinitialx J (1/nf2 – 1/ni2)  atomh  R(1/n12- 1/n22) E= -2.18x10-18 (Z2/n2) for Bohr atoms =h/mu Constants: Rydberg Constant = 1.097x107 m-1 1 eV= 1.60x10-19J Planck’s constant (h) = 6.626x10-34Js Speed of light (c) = 3.00 x 108 ms-1 Avogadro’s Number = 6.02x1023 particles/mole Electron mass = 9.11x10-31kg Proton mass = 1.67 x 10-27 kg Neutron mass = 1.67 x 10-27 kg 1 atomic mass unit (amu) = 1.66 x 10-27 kg Density of water= 1.00 gcm-3 1 pm = 10-12 m 1 Å = 10-10 m 1 nm = 10-9 m 1GHz = 109 Hz c= v Ephoton= h

Exam 1 version 1

You have 80 (eighty) minutes to answer all 24 questions, show your work for full credit, answers without any work will get a grade of ZERO. Points will be deducted for lack of units and wrong usage of significant figures. Section I. Nomenclature. (20pts) Provide the name or formula for the following compounds depending on what you are provided. 1. Strontium Hydroxide 2. Lead(II) Carbonate 3. Hydrosulfic Acid 4. Zinc Carbonate Hexahydrate 5. Disulfur Decafluoride 6. NO2(g) 7. Ni(ClO)2(s) 8. (NH4)3PO4(s) 9. HI(g) 10. HBrO3(aq) Section II. Conceptual Questions. (35pts) 11. What is the difference between a Law and a Theory? _______________________ _______________________ _______________________ _______________________ _______________________ _______________________ _______________________ _______________________ _______________________ _______________________

12. What are the units, according to the SI system, for the following parameters. a) Volume b) Temperature c)Density d)Velocity Answers:a)_________b)__________c)___________d)_________ 13. What is the difference between accuracy and precision?

14. What is an exact number?

15. What is the law of multiple proportions?

16. What is transmutation?

17. Lithium has two stable isotopes 6Li and 7Li. Since the atomic weight of lithium is 6.941, which is the more abundant isotope? Explain your answer.

Section III. Numerical Problems. (50pts) 18. 5pts, A running back in the VSU football team runs the 40m dash 16.33sec, maybe this is the reason the team can’t score, calculate his speed in km/h.

Answer:_________________ 19. 5pts, Perform the following calculations, report the answer to the correct number of significant figures: a. 2.34+(12.34*1.245)

Answer:_________________ 20. 10 pts, The density of lead is 11.3g/mL. How many grams of lead are there in 564.2mL?

21. 10pts, Express the following quantities in their respective SI units: a. 13.11 g

Answer: _________________ 22. 10pts, Silver has 46 know isotopes but of those only 2 Ag-107 and Ag-109 occur naturally. With the information provided calculate the atomic weight of silver: Silver-107 Atomic mass= 106.90509amu, abundance 0.5184; silver-109 Atomic mass= 108.90476amu abundance= 0.4816.

Answer:____________________ 23. 5pts, A compound of Carbon, Hydrogen and Oxygen contains 24.0g of Carbon, 6.06g of Hydrogen, and 16.01g of Oxygen. What is the total weight of a sample that contains 13.2g of Hydrogen?

Answer: ___________________ 24. 5pts, Provide the nuclear symbol for an atom that contains 17 protons, 20 neutrons and 18 electrons.