Given the balanced equation:

CaCO3(s) + 2HCl(aq) -->CaCl2(aq) + H2O(l) + CO2(g)

What is the total number of moles of CO2 formed when 20. moles of HCl is completely consumed?

(1) 5.0 mol (3) 20. mol

(2) 10. mol (4) 40. mol