Consider the following acid/base reaction CO3^2− + 2H^+ → H2O + CO2 that produces CO2 gas. 6 L of CO2 is collected at STP. What is the molarity of the HCl solution used in the reaction if 81 mL of HCl was needed?

Answer 1

6 L CO2. Knowing that 1 mol of any gas occupies 22.4 L at STP, then
6/22.4 = ? mols CO2.
Then using the coefficients in the balanced equation, that many mols CO2 x 2 = mols HCl used
Then M HCl = mols HCl/L HCl = ?