Using van der Waals equation, calculate the constant `a` when `2 mol` of a gas confined in a `4 L` flasks exerts a pressure of `11.0 atm` at a temperature of `300 K`. The value of `b` is `0.05 L mol^(-1)`.

Explanation

Van der Waals equation is
`(p+(an^(2))/(V^(2)))(V-nb)=nRT`
`n="2 mol, V = 4 L, p = 11 atm, T = 300 K,"`
`b="0.05 L mol"^(-1)`
Substituting the values
`(11+(axx4)/(16))(4-2xx0.05)=2xx0.082xx300`
`(176+4a)/(16)xx3.9=49.2`
`(176+4a)3.9=49.2xx16`
`15.6a=787.2-686.4`
`a="6.4615 atm L"^(2)"mol"^(-2)`