While a 1.00 L flask containing 1.500 atm of gas A is joined with a 1.00 L flask containing 0.750 atm of gas B, as well as the stopcock between the flasks is opened, also the gases are allowed to mix thoroughly, the following reaction proceeds at constant temperature. Explain what is the resulting total pressure of gases in now-joined flasks after the reaction proceeds to completion?
2A(g) + 3B(g) A2B3(g)
A. 0.375 atm
B. 0.750 atm
C. 0.625 atm
D. 0.225 atm