## Chemistry and Chemical Reactivity (9th Edition)

Van der Waals equation: $\left[P+a\left(\dfrac nV\right)^2\right](V-bn)=nRT$ $(P+6.49\ atm)×3.775\ L=122.43\ L.atm$ $P=25.93\ atm$ Ideal gas: $PV=nRT$ $P=30.61\ atm$ Percent error: $(30.61-25.93)/25.93×100\%=18\%$ That's a reasonably large error.