Another Chemistry Question (1 Viewer)

[qwertywerido]

Did this question twice, anyone mind telling me what l did wrong.

thanks !

 

[4321suomynona]

Prolly because u took the charge of silver as +2 and not +1. In HSC chemistry its usually +1. I rmb doing this same mistake where i searched up on google what is the charge of the silver ion and it said +2, and iirc my teacher said dont do that.

 

[jazz519]

Did this question twice, anyone mind telling me what l did wrong.
View attachment 34771
thanks !

Ag2S (s) < -- > 2Ag+(aq) + S2-(aq)

8.0 x 10^-51 = [Ag+]^2 [S2-]
8.0 x 10^-51 = (2x)^2 (x)
8.0 x 10^-51 = 4x^3
x = 1.2599210498949 x 10^-17

This is the molar solubility of Ag2S. What you did next overcomplicates the subsequent working for the question. This number represents c(Ag2S)

c(Ag2S) = 1.2599210498949 x 10^-17
n(Ag2S) = cv = (1.2599210498949 x 10^-17)(1.0) = 1.2599210498949 x 10^-17 moles
m(Ag2S) = n x MM = 1.2599210498949 x 10^-17 x (107.9x2+32.07)
m(Ag2S) = 3.1229663 x 10^-15 g

 

[jazz519]

Prolly because u took the charge of silver as +2 and not +1. In HSC chemistry its usually +1. I rmb doing this same mistake where i searched up on google what is the charge of the silver ion and it said +2, and iirc my teacher said dont do that.

Although their equation is written wrong without the charges displayed, the formula Ag2S uses Ag+ so this is not the mistake