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Unformatted text preview: 1-2 Fundamental Concepts Chap. 1 4. In a medical test for a certain molecule, the concentration in the blood is reported as 123 mcg/dL. What is the concentration in proper 81 notation? Solution:
123 mcg/dL = 10-3io-2 g/10-1 L = 1.23 X 10-6 g/L = 1.23 p,g/L. 5. How many neutrons and protons are there in each of the following nuclides: (a) loB, (b) 24Na,(c) 5900, (d) 208Pb,and (e) 235U? Solution: Nuclide neutrons protons
126 143 27
82 92 208Pb 235U 6. What are the molecular weights of (a) H2 gas, (b) H2O, and (c) HDO? Solution:
From Table A.3, A(O) = 15.9994gfmol; from Table B.1 A(H) = 1.007825 gfmol and A(D) = 2.014102gfmol. (a) A(H2) = 2 A(H) = 2 x 1.007825= 2.01565 g/mol (b) A(H2O) = 2 A(H) + A(O) = 2 x 1.007825 15.9994= 18.0151 g/mol + (c) A(HDO) = A(H) + A(D) + A(O) = 1.007825 2.014102+ 15.9994 + = 19.0213 g/mol What is the mass in kg of a moleculeof uranyl sulfate UO2S04? Solution: From Table A.3, A(U) = 238.0289 /mol, A(O) = 15.9994g/mol, and A(S) = g 32.066 g/mol. The molecular weight of UO2SO4is thus A(UO2S04) = A(U) + 6A(O) + A(S) = 238.0289+ 6(15.994)+ 32.066 = 366.091 g/mol = 0.336091kg/mol. Since one mol contains Na = 6.022 X 1023molecules,the mass of one molecule of UO2S04 = A(UO2S04)/Na = 0.366091/6.002 x 1023 = 6.079 X 10-25 kg/molecule. July 24, 2002 7. ...
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This note was uploaded on 02/01/2010 for the course ECE 4130 taught by Professor Cady during the Spring '06 term at Cornell University (Engineering School).
- Spring '06