Chem Q (1 Viewer)

[Vampire]

Hey guys, I'm just having a little trouble with these q's...can anyone explain them to me? Thx in advance..

0.60 M silver nitrate solution (50 mL) is added to 0.80 M sodium carbonate solution (50 mL).
The balanced ionic equation for the reaction that occurs is:
2Ag+(aq) + CO32–(aq) ===> Ag2CO3(s)

What amount (in mol) of Ag2CO3(s) precipitates?
a) 0.030 b) 0.30 c) 0.015 d) 0.020 e) 0.040

What is the final concentration of CO32–(aq) ions remaining in solution after the reaction?
a) 0.10 M b) 0.80 M c) 0.50 M d) 0.25 M e) 0.050 M

 

[pkc]

Before rxn,
Moles of Ag+ present=0.6M*.05L = 0.03
Moles CO32- present =0.8M*0.05L = 0.04

From the balanced equation you gave, the Ag+ is the limiting reagent, so it's the one which will determine the amount of Ag2CO3 produced.
(coz if all of the 0.04 moles of CO32 that is there reacted, it would need to consume 0.08 moles of Ag+ with it - and there just aint 0.08 moles of Ag+ there).

So, 0.015 moles of Ag2CO3 is produced (cos Ag+:Ag2CO3 is 2:1).

C is the answer to first bit.

Moles CO32- consumed = 0.015
Moles CO32- remaining = 0.04-0.015 = 0.025

Remaining [CO32-] = 0.025moles/ 0.1L = 0.2M


Hope it helps.

 

[pkc]

oops,

0.25M for last result

 

[Vampire]

wow thanks....you're a legend