[gauravsharma10167]

The formula for calculating Gibbs energy
ΔG=ΔG°+RT lnQ
Requires reaction quotient in terms of concentration or pressure?

I am asking this because reaction quotient in different terms will have different values which will give different values for Gibbs energy

[orthoformate]

If you are dealing with a solution, then they're asking for the concentration.

If you are dealing with a mixture of gasses, then you could express it as either concentration or pressure. This is because pressure is equivalent to concentration at constant temperature. PV=nRT rearranges to P=(n/V)RT.

[mjc123]

What is the standard state for which ΔG° is defined? If it is conc = 1M, use concentrations. If it is P = 1 atm, use pressures.