A chemistry problem concerning gas laws?

Acidic oxides such as carbon dioxide react with basic oxides like calcium oxide and barium oxide to form salts (metal carbonates). Write equations representing these two reactions. A student placed a mixture of BaO and CaO of combined m 4.88 g in a 1.46-L flask containing carbon dioxide at 35 degrees celsius and 746 mmHg. After the reactions were complete, she found that the CO2 pressure had dropped to 252 mmHg. Calculate the percent composition by m of the mixture. ume volumes of the solids are negligible. Thank you!