5I.33 Question

[jessicahedayi1H]

Hi,

I'm struggling with solving 5I.33 from the textbook.
A sample of ammonium carbamate, NH4(NH2CO2), of mass 25.0 g was placed in an evacuated flask of volume 0.250 L and kept at 25 °C. At equilibrium, 17.4 mg of CO2 was present. What is the value of Kc for the decomposition of ammonium carbamate into ammonia and carbon dioxide? The reaction is NH4(NH2CO2)(s)-> 2 NH3(g) + CO2(g).

The answer key uses ammonium carbamate in the ICE chart to solve this question, but it's considered a solid in the above equation. I thought solids weren't considered in ICE charts? Can someone explain why it's used in this ICE chart? Thanks!

[605775499]

I didn't include it and used the equation [NH3]^2[CO2] for K!
17.4mg=0.0174mg = 0.000395 mol CO2
0.000395/0.25L = 0.00158 M CO2
[2x]^2[x] = 4x^3 = 4(0.00158)^3
Kc=1.58x10^-8
Cheers o7