Determination of nitrogen dioxide content of the atmosphere Lab Report

Determination of nitrogen dioxide content of the atmosphere - Lab Report Example Apparatus include sampling probe, absorber, gas drying tube, air-metering device, thermometer, manometer, air pump, spectrophotometer, and stopwatch. Reagent grade chemicals have been used. Water free from nitrite and deionized according to specification D 1193 for type I or II reagent water has been used. Anhydrous sulfanilic acid has been used as the absorbing reagent, N-(1-Naphthyl)-Ethylenediamine Dihydrochloride stock solution (0.1 percent), Sodium Nitrite standard solution (0.0246 g/L) and NO2 permeation device were reagents and materials that were used in the experiment. 5.0012 g of anhydrous sulfanilic acid was dissolved in 1 L of water containing 140 mL glacial acetic acid. The process was gently heated to speed up the process. 20 mL of the of N-(1-naphthyl)-ethylenediamine dihydrochloride 0.1 % stock solution and 10 mL acetone were added, and diluted to 1 L. 0.1 g of the reagent was dissolved in 100 mL water.Calibration and StandardizationThe flowmeter was calibrated using practice D 3195. The gas meter was calibrated using test method D 1071. Standardization was based on observation. 0.82 mol of NaNO2 produced the same color as 1 mol NO2. 1 mL working standard solution contains 24.6 Â µg NaNO2. The amount of NO2 given by (24.6/69.1)x(46.0/0.82), which is 20 Â µg NO2. Standard conditions of 101 kPa and 25C were taken, and the molar gas volume was 24.47L (ASTM International 3). Graduated amounts of NaNO2 solution were added to a series of 25mL volumetric flasks up to 1 mL.