University:
Boston University
Course:
CAS CH 195 | Freshman Seminar in the Chemical Sciences
Academic year:

2020
Views:

331

Pages:

2
Author:

StellarSymphony

Factors affecting solubility Solubility determined by (Dill/3e pp 208) ΔGdissolve = … ΔEdissolve (surroundings) + ΔEorg (system) If ΔGdissolve < 0  soluble If ΔGdissolve > 0  insoluble We can predict ΔEdissolve We can predict ΔEorg (ion) Dill/3e p 211 MgCO3: ΔEorg makes ΔGdissolve > 0 ΔEdissolve = ΔElattice + ΔEhydration = + 3122 kJ/mol – 3148 kJ/mol = – 26 kJ/mol 2 ) + ΔE 2) ΔEorg = ΔEorg (Mg ( 2+ ( 32‐ org (CO = + 56 kJ/mol + 21 kJ/mol = + 77 kJ/mol ΔGdissolve = ΔEdissolve + ΔEorg = – 26 kJ/mol + 77 kJ/mol = + 51 kJ/mol  insoluble!!! AgCl: ΔEdissolve makes ΔGdissolve > 0 ΔEdissolve = ΔElattice + ΔEhydration = + 916 kJ/mol – 850 kJ/mol = + 66 kJ/mol ΔEorg = ΔEorg (Ag ( +) + ΔEorg (Cl ( l‐) = + 2.1 kJ/mol – 12 kJ/mol = – 10 kJ/mol ΔGdissolve = ΔEdissolve + ΔEorg = + 66 kJ/mol – 10 kJ/mol = + 56 kJ/mol  insoluble!!! 1 Solubility “rules” Soluble compounds • Na+, K+, and NH4+ • NO3−, CH3COO−, ClO4− • Cl−, Br−, I−, except with Ag+, Pb2+, Hg22+ • SO42−, except with Ag+, Pb2+, Hg22+, Ca2+, Sr2+, Ba2+ Insoluble compounds • CO32−, S2−, and PO43−, except with Na+, K+, and NH4+ • Ag+, Pb2+, Hg22+ • OH−, except with NH4+, Na+, K+, Ba2+ 2

Factors Affecting Solubility

of 2

Description

Free up your schedule!

Take 5 seconds to unlock