An impure sample of sodium carbonate, (Na2CO3) is allowed to react by dissolving it in an aqueous solution of 0.134 M HCl, according to the following reaction:
Na2CO3(s) + 2HCl(aq) → 2NaCl(aq) + CO2(g) + H2O(l)
If a 0.162 gram sample required 19.46 mL HCl to react completely, what is the weight percent of Na2CO3 in the original sample? (Express your answer as a percentage).