Solubility Rules & New MCAT

[futuredoctor10]

For those of you who have taken the new CBT MCAT, in the Physical Sciences section were you ever asked a specific detailed question requiring you to know detailed Solubility Rules?

In Kaplan they say that 3 rules cover the majority of solubility problems you'll see on test day:
1. All salts of alkali (IA) metals are water-soluble
2. All nitrates are water-soluble
3. All ammonium salts (NH4+) are water-soluble

Did anyone get a question on solubility where you had to know more detailed rules?

(Also those studying and those who took the exam)-- I do not know if it is worth memorizing all the solubility rules for 1 or 0 questions in the Physical Sciences section. Opinions?

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[engineeredout]

EK's gen chem has a whole section on solubility rules but it says that you don't really need to know them (and once I see that, my mind shuts off). Seems to me from what I've practiced is the biggest thing you need to keep track of for solutions is lechatlier's principal (knowing that adding something will shift the EQ in the opposite direction) and partial pressures (raoults & henry's law)

 

[futuredoctor10]

Sidenote: Also in the same online workshop on Solutions where Kaplan listed the solubility rules, it said in the summary page: "On Test Day you will see plenty of questions which assume you know which of the reactants are soluble in water." I am assuming they will be more obvious reactants than particulars or exceptions.

Thanks, engineeredout. I think you are right that this is not a frequently tested topic- those other topics you've listed are definitely more important. Just wanted to make sure you don't have to know solubility rules to score well / and that questions covering these rules are maximum 1 or 2 per section...

 

[dodjie16]

Yes, I was actually asked a solubility question on the real MCAT. In fact, it asked about the solubility of a gas in liquid.

Know these rules for the MCAT:

Solubility rules:
All Group 1 and ammonium salts are soluble in water.
All nitrate, perchlorate, and acetate salts are soluble in water.
All silver, lead, and mercury salts are insoluble in water except for their nitrates, perchlorates, and acetates.

The solubility of a solid in liquid increases with increasing temperature.
The solubility of a gas in liquid decreases with increasing temperature.
The solubility of a gas in liquid increases with increasing pressure.

 

[futuredoctor10]

Thanks!