Hydroxyapatite, Ca 10 ( PO 4 ) 6 ( OH ) 2 , has a solubility constant of Ksp = 2.34 × 10 − 59 , and dissociates according to Ca 10 ( PO 4 ) 6 ( OH ) 2 ( s ) − ⇀ ↽ − 10 Ca 2 + ( aq ) + 6 PO 3 − 4 ( aq ) + 2 OH − ( aq ) Solid hydroxyapatite is dissolved in water to form a saturated solution. What is the concentration of Ca 2 + in this solution if [ OH − ] is fixed at 3.90 × 10 − 6 M ?

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: