# Chemistry Daily Challenge 25-July-2015

**Chemistry**Level pending

van der Waals equation is \[\left(p+\frac{a}{V^2}\right)\left(V-b\right)=RT\] Given: \(\frac{\partial P}{\partial V}=0 \quad and \quad \frac{\partial^2 P}{\partial V^2}=0 \quad \text{at critical point}\)

If a and b can be expressed as \[a=\frac{pR^2T_c^2}{qP_c}\quad b=\frac{rRT_c}{sP_c}\]

where \(T_c,P_c,V_c\) are critical properties. p and q coprime integer.r and s are coprime integer. \(\color{blue}{\text{Find the value of p+q+r+s.}}\)