Question

In a closed 1.00 L flask, 4.30 atm of CO reacts with 2.50 atm of O2 according to the equation below. Assuming that the temperature remains constant, what is the final pressure in the flask?

Answer 1

2CO + O2------>     2CO2

2 moles      1 mole

4.3 atm       2.5 atm   0    initial

-4.3 atm     - 2.15 atm          4.3atm    change

0                 0.35atm          4.3 atm at euilibrium

from the balanced equation

2 moles of CO react with 1 moles of O2

4.3 atm of CO react with = 4.3/2 = 2.15 atm of O2

Here limiting reagent is CO

2 moles of CO react with O2 to form 2 moles of CO2

4.3 atm of Co react with O2 to form 4.3 atm of CO2

remaing pressure of O2 = 2.5-2.15 = 0.35 atm

total pressure of the flask = PO2+ PCO2

                     = 0.35 + 4.3= 4.65 atm