118. Solving a chemistry problem

Air containing an admixture of formaldehyde was drawn at a rate of 0.5 l/min for 20 min through an absorbing flask with 6 ml of water. After aspiration, the solution was transferred to a volumetric flask with a capacity of 25 ml, the background electrolyte was added, and the mixture was made up to the mark with water. After polarography, the height of the peak at E = -1.6 V was 28 mm. To construct a calibration curve, 2 ml of a standard solution with a formaldehyde concentration of 2*10-2 mg/ml was placed in a 250 ml volumetric flask (solution 1). In five volumetric flasks with a capacity of 50 ml poured 1;2;3;4;5; ml of solution 1, background was added and the volume was brought up to the mark with water. When polarography received the following peak heights 8; 15;25;31;41; mm . Determine the formaldehyde content in 1 m3 of air.