THESE QUESTIONS ARE IN CONTEXT OF

CHEMISTRY REGARDING COMBUSTION OF LIQUID FUELS ;: AND chemistry numericals.

A$.$Why for molar analysis $,$ entropy production $,$ mass flow rate of fuels in Chemistry numericals we use IDEAL GAS laws, assumptions?

Won't the reactions in real world not be like ideal gas $?$ Are they used as an approximation and that they are easier to solve them then real gas $?$

B $.$WHAT IS air to fuel ratio in Chemistry sums in $($ Combustion reactions$)/$ use and need?

C$.$ For these kind of reactions do we need to apply mass flow rates etc same as that of thermodynamics? What is mass flow

rate in fuel Chemical reactions

D$.$ What is molar analysis $,$ entropy production and entropy of a reaction? Is it disorder of a reaction $?$ If so then disorder of what $?$

E$.$ What is mole fraction? What is mass fraction