An aqueous solution containing the [Cu(NH3)4]2 complex ion was analyzed at 580 nm using a SpectroVis spectrophotometer and a cuvette with a 1.0 cm path length. The absorbance of the solution was 0.301. If the equation of the line for the calibration plot of [Cu(NH3)4]2 at 580 nm is y = 56.0x + 0.0081.
What is the concentration of [Cu(NH3)4]2+ in the solution?

In vapor-liquid equilibrium in a binary mixture, both components are generally present in both phases. how many degrees of freedom are there for such a system? the reaction between nitrogen and hydrogen to form ammonia occurs in the gas phase. how many degrees of freedom are there for this system? steam and coal react at high temperatures to form hydrogen, carbon monoxide, carbon dioxide, and methane. the following reactions have been suggested as being involved in the chemical transformation: