Chemistry 104 Test #2D October 13, Please follow these instructions

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1 hemistry 104 Test #2D ctober 13, 2009 Please follow these instructions 1. There is only 1 correct answer for Multiple-choice questions (choose the best answer) 2. Please remember that only the answer sheets will be graded so record all your answers on the answer-sheet 3. Use the periodic table attached 4. onstants and formulas: R = atm.l/mol.k

2 ctober 13, 2009 Test 2 hemistry 104 Student s Name: Answers Formula if any used Answers Formula if any used

3 Test # 2D hemistry 104 Fall 2009 Dr Pierre Goueth Student s Name: Multiple hoice Questions (2 pts each) 1. ow much energy would be released as the temperature of 150 grams of copper (specific heat = cal/g ) drops from 79.0 to 50.0? A. 3 cal B. 402 cal cal D cal 2. A hurricane might be preceded by an atmospheric pressure of 727 torr. Express 727 torr in atm of pressure. A atm B atm. 1,05 atm D atm 3. Standard temperature and pressure, STP is. A. 0 and 1 atm B. 25 and 1 atm. 37 and 1.01 atm D. 100 and 2 atm 4. A cylinder of gas originally at 28.0 and 1.00 atm of pressure to is heated to What is the new pressure? A atm B atm atm D atm 5. A balloon containing 0.56 mole of helium has a volume of 10.0 L. What volume will the balloon occupy if helium is lost and only 0.21 mole remain? A. 27 L B. 3.8 L. 2.1 L D. 5.6 L 6. A pressurized tank contains nitrogen at 1.3 atm, oxygen at 0.7 atm, and helium at 0.1 atm. The reading of the pressure gauge is expected to be. A. 0.5 atm B atm. 1.3 atm D. 2.1 atm 7. What is the volume of a mole of an ideal gas under standard conditions (STP)? A liter B. 760 liters liters D. 1.0 liter 8. A balloon with a volume of 4.5 L at a temperature of 23.0 o is taken outside where the temperature is 2.0 o. What is the new volume of the balloon? A L B. 52 L. 4.8 L D. 4.2 L 9. The viscosity of a liquid is the measure of. A. its internal pressure B. the size of the molecules present. its chemical composition D. its resistance to flow 10. The viscosity of liquids is most affected by. A. pressure B. volume. temperature D. none of the above 21. According to the octet rule, how many valence electrons are present in a chloride ion (l - )? A. 1 B D Which two ions are isoelectronic (same number of electrons)? A. K + and l - B. Mg 2+ and Be 2+. Be 2+ and 2- D. Li + and I -

4 13. Generally, the octet rule works fairly well for predicting the behavior of atoms. owever, there is an exception. A. The halogens do not form ions on the basis of the octet rule. B. The alkali metals only conform to the octet rule when producing neutral atoms.. The transition metals do not necessarily conform to the octet rule. D. The nonmetals do not conform to the octet rule. 14. The formula for ammonium chloride is A. All3 B. N4l. Nl D. Aml 15. The difference between an ionic bond and a covalent bond is that A. ionic bonds commonly occur between two metals and covalent bonds occur between metals and nonmetals B. ionic bonds are between atoms that can share electrons; covalent bonds are between atoms that will donate/accept electrons. covalent bonds come about because of a sharing of electrons; ionic bonds don t D. ionic bonds are between smaller atoms; covalent bonds are between large atoms 16. What is the proper name of the compound N23? A. nitrate B. nitrogen(ii) oxide. nitrogen trioxide D. dinitrogen trioxide 17. Aluminum sulfate, Al2(S4)3, can be used as an anti-infective. What is the formula weight of this salt? A amu B amu amu D amu 18. Glycerol, often called glycerine, was used as a skin moisturizer before more commercial preparations were made available. alculate the weight of 7.85 moles glycerin. A grams B. 228 grams. 667 grams D. 722 grams 19. The specific gravity of a substance is the A. definite affect of gravity on that substance. B. comparison of the density of the substance with that of water.. the mass of the substance squared divided by its volume. D. the inverse of the density of the substance. 20. Which molecule can exist as cis and trans isomers? A. 1,2-dimethyl cyclopentane B. cyclopentane. 1,1-dimethylcyclopentane D. methyl cyclopentane 21. Which compound can exist as cis and trans isomers? A. 2-methyl butane B. 2,3-dimethyl pentane. 1-butene D. 2-butene

5 22. Shown at the right is the structure of butyric acid. Which choice below is the skeletal structure for butyric acid? A. B.. D ,1-dimethyl cyclopentane and 1,2-dimethyl cyclopentane are. A. different conformations of the same compound B. constitutional isomers. geometric isomers D. the same 24. n the basis of the electronegativities provided, which bond is most likely to be ionic? A. calcium(1.0) and carbon (2.5). B. potassium (0.8) and bromine (2.8).. sulfur (2.5) and oxygen (3.5). D. magnesium (1.2) and phosphorous (2.1). 25. The strongest noncovalent interaction that can occur between hydrocarbons is. A. dipole-dipole forces B. hydrogen bonding. ion-dipole interaction D. London force 26. is-2-pentene and trans-2-pentene are. A. different conformations of the same compound B. constitutional isomers. geometric isomers D. the same 27. Which of the following molecules has the highest boiling point? A. propanol B. propane. propene D. propyne 28. hose the incorrect statement describing the alkane family. The alkanes A. are nonpolar molecules. B. are all composed of unbranched chains of carbons (straight chains).. boil at a higher temperature with increasing length of the carbon chain. D. with short carbon chains (1 to 4 carbons) tend to be gases at room temperature. 29. According to harles' law when the Kelvin temperature of a gas doubles (at constant pressure), its volume will. A. double B. reduced to ½. quadruple D. remain the same 30. Which is the correct name for this hydrocarbon? A. 3-methylheptane. B. 2-ethylhexane.. butylethylethane. D. butylethylmethylmethane.

6 31. Suppose you want to decrease the density of a sample of liquid mercury at room temperature. Which of the following would accomplish that purpose? A. Decrease the pressure by 5 torr. B. Decrease the temperature by 5 degrees.. Increase the pressure by 5 torr. D. Increase the temperature by 5 degrees. 32. Naming cyclic compounds is similar to naming straight chain compounds. This compound is A. 1,1,2-trimethylcyclohexane. B. 1,2,2,-metholatedhexanecyclic. trimethylcyclohexane. D. 2,2-dimethylcyclonone Name the compound drawn here. A. isopropylethylethyne B. 1,1-dimethyl-2-pentyne. 1-isopropyl-1-butyne D. 2-methyl-3-hexyne 34. What is the major component that identifies an aromatic compound? A. There will be parent chains containing more than one cyclic functional group. B. Aromatic compounds always contain a long parent chain and a cyclic portion.. There are rings of carbons chemically bonded by alternating single and double bonds. D. The longer the parent chain, the more likely the compound is to have a scent. 35. Which of the following defines "heat of fusion"? A. The amount of heat energy necessary to raise the temperature of 1.00 gram of a substance 1.00 o. B. The amount of heat energy necessary to raise the temperature of 1.00 gram of water 1.00 o.. The heat absorbed or released when a substance melts or freezes. D. The heat absorbed or released when a substance vaporizes or condenses. 36. A 5.00 ml sample of octane, one of the liquids found in gasoline, has a mass weighing 3.55 grams. What is the density of octane? A g/ml B g/ml g/ml D g/ml 37. A gas cylinder at a pressure of 5.80 atm contains both helium and oxygen. The helium is at a pressure of 2.35 atm. What is partial pressure of oxygen? A atm B atm atm D atm 38. What is the specific gravity of a urine sample with a volume of ml and a mass of g? A B D In Death Valley which is located below sea level, the atmospheric pressure exceeds 760 torr. Water boils at A. less than 100 º B. 100 º. more than 100 º D. will never boil 40. The number of calories required to raise the temperature of 75 grams of water from 23.0 to 31.0 is.(specific heat capacity of water is 1 cal/g 0 ) A cal B. 713 cal. 600 cal D. 248 cal

7 Short Answers Show all necessary calculations. Include all necessary units. Round answers to the correct number of significant figures. Box final answers. 1. ow many moles of helium are present in a 5.00 L cylinder at a pressure of 3.85 atm and a temperature of 24.0 º? (3 pts) 2. ow much heat energy is necessary to convert 95.0 g of ice at 0 º to liquid water at 0 º? (heat of fusion of water is 79.7 cal/g) (3 pts) 3. Draw the structures of the following: (4 pts) 2-pentyne meta-diethylbenzene

8 4. Sketch the structural formula for each of the following. Determine the molecular geometry and molecular polarity and the formal charge of each of the atom present. (6pts) Formula Lewis Structure Formal charge of each atom Molecular Geometry Molecular Polarity Se2 : Se: N2 - N: : : NF3 N: F:

A. They all have a benzene ring structure in the molecule. B. They all have the same molecular formula. C. They all have carbon and hydrogen only

Ch 21 G12 CoreI- Choose the best answer, then transfer your answers to page (1) [32 marks; 2 each] 1. What characteristic do all aromatic hydrocarbons share? A. They all have a benzene ring structure in