When stating the volume of a gas the pressure & temperature should also be given why??
Answers
To completely define the state of the system/substance, a certain minimum number of properties are required to be known. These are referred to as independent properties. Independent properties are measurable quantities. The state of a gas of mass m in the cylinder is completely specified by knowing the pressure P and temperature T or by knowing temperature T and specific volume v or by pressure P and specific volume v. Thus either P and v or P and T or T and v two independent properties of system/ substance. That is the State of the system can be represented by two independent properties. In order to represent the state of the system graphically in an x-y axis we require two independent properties.
The value of remaining properties can be determined in terms of independent properties. This properties are dependent properties like entropy, enthalpy, internal energy ect..
Come to you question during stating the volume of the gas we need state either temperature or pressure , because minimum two independent properties are to be required to define the state of the system. Not all the three required.