The heterogeneous reaction CaCO3(s)+2HCl(aq)⇌CaCl2(aq)+H2O(l)+CO2(g) occurs in a vessel that contains 1.00 L of solution beneath a 2.00 L gas headspace at 298 K. Before any reaction takes place, the solution contains 0.0500 mol HCl and 0.0200 mol CaCl2, and the headspace contains CO2 at 1.20 atm. Assuming ideal behavior and that the volume of the solution is exactly 1.00 L, calculate the numerical value of the reaction quotient Q at this initial moment.