A 25.0 mL sample of waste water is obtained to analyze for Pb2 ions. This sample is evaporated to dryness and redissolved in 2.0 mL of H2O, mixed with 2.0 mL of a buffer solution and 2.0 mL of a solution of dithizone then diluted to 10.0 mL. The absorbance of the colored Pb2 - dithizone complex is compared with the Beer-Lambert plot below. 8. The absorbance of a portion of the final solution is 0.13. What is the concentration of Pb2 ions in the waste water in ppm

Nitric oxide (no) can be formed from nitrogen, hydrogen and oxygen in two steps. in the first step, nitrogen and hydrogen react to form ammonia: n2(g) + 2 h_2(g) rightarrow 2 nh_3 (g) delta h = -92. kj in the second step, ammonia and oxygen react to form nitric oxide and water: 4 nh_3(g) + 5 o_2(g) rightarrow 4no(g) + 6 h_2o(g) delta h = -905. kj calculate the net change in enthalpy for the formation of one mole of nitric oxide from nitrogen, hydrogen and oxygen from these reactions. round your answer to the nearest .

Calculate the mass of silver needed to react with chlorine to produce 126g if silver chloride?

Astudent reacts 13 moles of iron with 21 moles of oxygen according to the following equation: