A mixture of oxygen and neon gases is maintained in a 9.72 L flask at a pressure of 2.55 atm and a temperature of 81 °C. If the gas mixture contains 8.52 grams of oxygen, the number of grams of neon in the mixture is

The mass has escaped into a gas which you can not see so the law stays true.

B? i feel like this is a trick  

The answer is c - the principal of original lateral continuity. 

Answer is: value of q is 5·10⁻⁶m.chemical reaction: mg²⁺(aq) + co₃²⁻(aq) → mgco₃(s).c(mg²⁺) = 2.5·10⁻³ m; concentration of magnesium cations.c(co₃²⁻) = 2.00·10⁻³ m; concentration of carbonate anions.q = c(mg²⁺)  · c(co₃²⁻).q = 2.5·10⁻³ m  · 2.00·10⁻³ m.q = 5·10⁻⁶m.q = 0.000005 m.