Which of the following is the correct expression for an irreversible process?

What is meant by absolute entropy?

Given that $\Delta H = 0$ for the mixing of two gases,explain whether the diffusion of these gases into each other in a closed container is a spontaneous process or not?

In which of the following reactions is $\Delta S$ positive?

Which of the following reactions will have the value of $\Delta S$ with a negative sign?

Calculate $\Delta S_{\text{total}}$ for a certain reaction if $\Delta H = -150 \ kJ$ and $\Delta S = 32 \ JK^{-1}$ at $300 \ K$. (in $JK^{-1}$)