Does anyone know this?

Which is the solubility product expression for caf2(s)?  [ca2+]/[f–]2  [ca2+][f2–]  [ca]+[f]2  [ca2+][f–]2

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:

6) (a) calculate the absorbance of the solution if its concentration is 0.0278 m and its molar extinction coefficient is 35.9 l/(mol cm). the depth of the cell is 5 mm. (b) what is the %t? (7) calculate the absorbance of the solution if the transmitted light intensity is 70% of the initial light beam intensity