Apchp2wskey - AP Chemistry — Chapter 2 Supplemental Class...

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Unformatted text preview: AP Chemistry — Chapter 2 Supplemental Class Problems Name: % 4 Date: ' Period: 1. It is common in chemistry to assume that the mass of a cation is the same as that of its parent atom. a) Using the following data: p = 1.0073amu, n = 1.0087amu and e = 5.486x10'4amu, determine the number of significant figures that must be reported befor differenfce in mass of 11H and 11H+ is significant. I k # ; A an 7 3 5‘ 5: ‘ f7 5 , fl 2 50797372., 0005pr =/, 5,078; b) What percentage of the mass of an 11H atom does the electron represent? a -7 5' i 5 yu'xw /,0o7?§ ,WS‘I‘)’ 7 0’05VV2 2. The diameter of a US. penny is 19mm. The diameter of a copper atom, by comparison, is only 2.613;. How many copper atoms could be arranged side by side in a straight line across the diameter of a'penny? [Claim '7 _ s r 2 ‘ 9716700 7mm as x D 4%” ‘7 at m 3. Using the mass of the proton and assuming its diameter is 1.0x10'15m, calculate the density of a proton . _ - r a 3 mg/C ' WP ' /. hzezzxm “’7 Veg—1W3 s k1 - Auzrnx/p‘HJ {5 1xm'ri/ I : y //,oxxa"’cm 3 .. -yo : "— ' v - 6...; ——1T =$;ZVx’/y g / V {a 71*) oavo 3 7_ ) oh? 4. The mass-to-charge ratio of the positron (a product of the radioactive decay of certain isotopes) is ~ 5.6x10'12 kg/C. The charge on a positron is the same as that on a proton. Calculate the mass of a positron. Does any other fundamental particle have this same mass? Explain. + _ -, Q? 1 A401”? 19C $9xw‘”£% U-éozx/o )7“) ' t » ,‘3' 50”“; "14,5545 2 9. 97x/o’3/k7 l 9‘aK/0 £7’g/w‘mn Afar/«IVE (4’7" 5. The atomic masses of the five naturally occurring isotopes of germanium are germanium-70, 69.9243u; germanium-72, 71.9217u; germanium-73, 72.9234u; germanium-74, 73.9219u; germainium—" 76, 75.9214u. Use these values and data from the accompanying bar graph mass spectrum of germanium to determine a weighted average atomic mass of germanium.‘ {53'1'7‘05 71' {72 '73- :74 75 ' 7‘6 77 ’ s * .- Massnumber »» » 6. In mass spectrometry, molecules are ionized, and some of the ionized molecules are fragmented. Masses of the molecular ions and ionized fragments are found using magnetic and/or electric fields of known strength, and the relative numbers of fragments are plotted as a function of their mass-to-charge ratios, m/z. Because the ions typically carry a charge of 1+, for the majority of fragments, the m/z ratios 1 also represent mass numbers. The mass spectrum of elemental bromine (Brz) is shown below. Explain what species the peaks at 79, 81, 158, 160 and 162 represent. Why is the peak at 160 about twice that height of the ones at 158 and 162? I . v E » .EM '2 I»? ’ ........L..,,..,~ifl..WW... x . g i .. , _V I. H , 7. Natural chlorine, which has an atomic mass of 35.4527u, consists of c lorine-35 and chlorine—37 isotopes. Given that the mass of chlorine-35 is 34.96885u, what is the average atomic mass (in u), of a chlorine sample prepared by mixing equal numbers of chlorine atoms from a sample of natural chlorine andasample of ure chlorine-35? I - v : y. gé fl, ,Va hora/C. rrri-C :, 3‘s" ¢§17M “L 35 3 5—44 25': § 37.76355- avera5+= rag/,— ~ 3572/06“ 8. A hypothetical element X is found to have an atomic mass of 37.45u.‘ Element X has only two isotopes, X-37 and X-38. The X-37 isotope has a fractional abundance of 0.7721 and isotopic mass of 37.24. What is the isotopic mass of the other isotope? x s 27. 5/; =0» )[wss Xe?) +6930?“ 4X43) :(.77zl)(37,2</ + (1".77’2-l ’I’L - I 37,95:{.77g/l’37.29)+(.u7e)(%) 6.637 2 (.2275W’b) 7°: 8’33:b . enum er 9. A monoatomic ion has a charge of +3. The nucleus of the ion has a mass number of 27. of neutrons in the nucleus is equal to the number Of electrons in a 82+ ion. Identify the element and indicate the number of protons, neutrons, and electrons. S 1* 2 3L / [W 7* wwn/ Su/flw’ .' /55/&c/rms WM Sit/[W : “Mama”, 5/: as a; X” WM»; W5; 4/5 ><J*:y+/4~.27 é‘pm‘tw5u3 acwswu,mmmmi) . . . . . ’3 P“, '06 / 7n“ . 10. Wh11e traveling to a distant universe, you discover e hypothetical element “X”. You obtain a representative sample of the element and discover that it is made up of two isotopes, X—23 and X-25. To help your science team calculate the atomic mass of the substance, you send the following drawing of your sample with your report. In the report, you also inform the science team that the light atoms are X-23, which have an isotopic mass of 23.02u, and the dark atoms are X-25, which have an isotopic mass of 25.147u. What is the atomic mass of element X? 5- ‘ FVAJ/M/ lbw/’42)?“ d/ X-Zl 3 Z; 3.25 FrAL/‘IW/ 1940/”an 6 X‘25 CA 3' f 20 X : [. ZS’Y23,02) +C,7§YZ§‘./97) Z ,"\ ...
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This note was uploaded on 12/07/2011 for the course CHEM 100 taught by Professor Feebeck during the Fall '10 term at Purdue.

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Apchp2wskey - AP Chemistry — Chapter 2 Supplemental Class...

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