DAT Destroyer Gen Chem 22

[Demo0710]

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Which of the following compounds would be most soluble in NH3?

a) K2CO3
b) NaBr
c) AgBr
d) CaCl2
e) LiNO3

The answer is C, because transitional elements can make complex ions so it forms Ag(NH3)2+.

Aren't choices A and B also soluble since Group I + ammonium is soluble?

 

[Happyfaace]

ok, so I was going through Chad's notes. And came across the notes saying that acidic salts are more soluble in basic solutions and v.v. basic salts are more soluble in acid. If you have purchased his videos, go to section 5.9 of gen. chem.
Hope this helps.

 

[quocstazz]

Which of the following compounds would be most soluble in NH3?

a) K2CO3
b) NaBr
c) AgBr
d) CaCl2
e) LiNO3

The answer is C, because transitional elements can make complex ions so it forms Ag(NH3)2+.

Aren't choices A and B also soluble since Group I + ammonium is soluble?

Agbr is acidic. as a result when you react with a base, nh3 in this case, the base will bind to Ag to become ag(nh3)2. As a result this will shift equilibrium to right and agbr will keep on dissolving

Sent from my SPH-D710 using Tapatalk

 

[Demo0710]

Can one of yall explain why the other options aren't acidic?

 

[ScarletKnight24]

Which of the following compounds would be most soluble in NH3?

a) K2CO3
b) NaBr
c) AgBr
d) CaCl2
e) LiNO3

The answer is C, because transitional elements can make complex ions so it forms Ag(NH3)2+.

Aren't choices A and B also soluble since Group I + ammonium is soluble?

The question is asking which is soluble in NH3, NOT in water.

Choices A, B, and E are all soluble in WATER because they contain group 1 salt.

AgBr dissociates to Ag+ and Br- and acidic salt can go react with a base(ammonia in this case)

HOWEVER, chad also mentioned that some textbooks even include Ag+ as one of the negligible salt so it won't react with a base.

SO all in all, it is unlikely that you will see this question.

 

[ScarletKnight24]

Can one of yall explain why the other options aren't acidic?

1) K2CO3 ---> basic salt
because K+ is a conjugate acid of a strong base therefore it has NO acidic property. CO3 is NOT a conjugate base of a strong acid so it DOES have some basic property

2)NaBr --- Neutral
because Na is a conjugate acid of a STRONG base and again it has no acidic property. Br- is a conjugate base of a STRONG acid so it has NO basic property

3) AgBr = Ag+ is acidic (SLIGHTLY, although some textbooks say that it is negligible)
Br- has no basic property for the same reason I mentioned above.

4). CaCl2 = neutral for the same reason as #2

5). LiNO3 - neutral

REMEMBER.

The STRONGER your acid , the WEAKER your conjugate base and vice versa.