In: Chemistry
Would be activity of Cl- be greater or less in seawater than in water from the Mississippi River? Answer the same question for the activity coefficient. Explain your answers!!!
Activity of sea water is less than activity of mississippi river
Activity coefficient of sea water is less than activity coefficient of mississippi river
Explanation
Ionic strength of sea water is high due to more dissolved soilids
Ionic strength, I calculated as follows
I = 1/2 ( c1×z22 + c2×z22 + c3×z32+.....)
where,
c1, c2, c3 etc are concentration of ions 1,2,3 etc
z1, z2, z3 etc are charges of ions 1,2,3etc
ionic strength and activity coefficient, , are related as follows
log1= - 0.51×z12× √I/(1+3.3 × × √I )
Where, is diameter of hydhydrated ion
thus activity coefficient is decreasing when ionic strength is increasing
activity,a, formula is
a = c
where , c is concentration
So, activity is decreasing when activity activity coefficient decreasing
therefore,
Due to high ionic strength of sea water, activity and activity coefficient is less for sea water than for Mississippi river.