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Unformatted text preview: 119. The nitrogen content of organic compounds can be determined by the Dumas method. The compound in question is first reacted by passage over hot CuO(s): Hot Compound----c > N 2 (g) + COig) + H 2 0(g) (uo(.<) The product gas is then passed through a concentrated solution of KOH to remove the CO 2 , After passage through the KOH so- lution, the gas contains N2 and is saturated with water vapor. In a given experiment a 0.253-g sample of a compound produced 31.8 mL N2 saturated with water vapor at 25C and 726 torr. What is the mass percent of nitrogen in the compound? (The va- por pressure of water at 25C is 23.8 torr.) 120. An organic compound containing only C, H, and N yields the following data. i. Complete combustion of 35.0 mg of the compound produced 33.5 mg CO 2 and 41.1 mg H 2 0. ii. A 65.2-mg sample of the compound was analyzed for nitrogen by the Dumas method (see Exercise 119), giving 35.6 mL N2 at 740. torr and 25C. iii. The effusion rate of the compound as a gas was measured and found to be 24.6 mL/min. The effusion rate of argon gas, under identical conditions, is 26.4 mUmin. What is the molecular formula of the compound? 121. Atmospheric scientists often use mixing ratios to express the con- centrations of trace compounds in air. Mixing ratios are often expressed as ppmv (parts per million...
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This note was uploaded on 12/13/2010 for the course CHEM 2301 taught by Professor Bill during the Spring '10 term at South Texas College.
- Spring '10
- Organic chemistry