Please HELP Water can be separated into its elements. If 20.0 g water is decomposed by this method, how many liters of oxygen gas will be produced assuming STP? 2H2O --> 2H2 + O2

6.23 L oxygen gas

12.4 L oxygen gas

11.2 L oxygen gas

7.00 L oxygen gas

Sorry i dont understand the question can you rephase it?

The answer to your q the total mass is 73

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.