posted by Kara .
A 9.00-L container holds a mixture of two gases at 43 °C. The partial pressures of gas A and gas B, respectively, are 0.257 atm and 0.579 atm. If 0.110 mol a third gas is added with no change in volume or temperature, what will the total pressure become?
Use PV = nRT and calculate the partial pressure of the third gas, than add the partial pressure of the three to obtain the total.