  Considering the variable cosmological constant in the extended phase space
has a significant background in the black hole physics. It was shown that the
thermodynamic behavior of charged AdS black hole surrounded by the quintessence
in the extended phase space is similar to the van der Waals fluid. In this
paper, we indicate that such a black hole admits the same criticality and van
der Waals like behavior in the non-extended phase space. In other words, we
keep the cosmological constant as a fixed parameter, and instead, we consider
the normalization factor as a thermodynamic variable. We show that there is a
first-order small/large black hole phase transition which is analogous to the
liquid/gas phase transition in fluids. We introduce a new picture of the
equation of state and then we calculate the corresponding critical quantities.
Moreover, we obtain the critical exponents and show that they are the same
values as the van der Waals system. Finally, we study the photon sphere and the
shadow observed by a distant observer and investigate how the shadow radius may
be affected by the variation of black hole parameters. We also investigate the
relations between shadow radius and phase transitions and calculate the
critical shadow radius where the black hole undergoes a second-order phase
transition.
