Q, reaction quotient

Kf = molal freezing-point depression constant Kt,= molal boiling-point elevation constant A = absorbance a= molar absorptivity b = path length c= concentration Q = reaction quotient /= current (amperes) q= charge (coulombs) f= time (seconds)... 

Q reaction quotient at specified T, P, pH, pMg, and 7i activity coefficient of species /... 

That is, the particular function of the three concentrations defined by Q (reaction quotient) is always the same at equilibrium. This is true even though any individual concentration may vary by as much as a magnitude of 10. This unifying principle allows the calculation of conditions at equilibrium under virtually any set of conditions. 

The product of the concentrations of any two ions (raised to the appropriate powers) in a solution is called the ion product, Q, which is similar to the Q (reaction quotient) of Chapter 16. Whenever the Q calculated from known solubility data is less than the value of its solubility product, the solution is not saturated. 

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