The spontaneous flow of heat is always

$3$ moles of water is boiled at $373 \ K$ and is changed to vapour state having the same temperature. What will be the change in entropy of the system (in $kJ/K$)? [ The molar heat of vaporization of water is $40.668 \ kJ/mol$ ]

In a reversible adiabatic process $\Delta S$ is :-

Calculate the entropy change in the surroundings when $1.00 \ mol$ of $H_2O_{(l)}$ is formed under standard conditions. Given: $\Delta_f H^{\theta} = -286 \ kJ \ mol^{-1}$.

$18 \ g$ of ice is converted into water at $0 \ ^\circ C$ and $1 \ atm$. The entropies of $H_2O_{(s)}$ and $H_2O_{(l)}$ are $38.2$ and $60 \ J/mol \ K$ respectively. The enthalpy change for this conversion is ..... $J/mol$.

$A$ container has a hydrogen and oxygen mixture in a ratio of $4 : 1$ by weight. When these gases are mixed,which of the following occurs?