The maximum contaminant level of copper (cu) in drinking water as set by the the environmental protection agency (epa) is 0.0013 g⋅l−1 . express this concentration in parts per million (ppm). assume the density of water is 1.00 g/ml .

Answer is: concentration is 1.3 ppm.

Parts-per-million (10⁻⁶) is present at one-millionth of a gram per gram of sample solution, for example mg/kg.

d(Cu) = 0.0013 g/L; mass concentration of copper.

d(H₂O) = 1.00 g/mL; density of water.

m(H₂O) = V(H₂O) · d(H₂O).

m(H₂O) = 1000 mL · 1 g/mL.

m(H₂O) = 1000 g ÷ 1000 g/kg.

m(H₂O) = 1 kg; mass of water.

m(Cu) = 0.0013 g · 1000 mg/g.

m(Cu) = 1.3 mg; mass of coppper.

concentration = 1.3 mg ÷ 1 kg.

concentration = 1.3 mg/kg.

concentration = 1.3 ppm.

answer: the value of enthalpy change will be -152.80 kj.

solution:

pressure = 1atm , temperature = = 298 k

given that pressure and temperature are same in both gases , the number of moles of both gases can be determined by the ideal gas equation.

according to reaction 3 moles no are reacting with 1 mol of ,then 0.49 mol of no will react with moles of ozone that is 0.16 moles of ozone. since, no is limiting reagent and is an excessive reagent.

enthalpy change for the reaction between the given volumes of the gases is :