What is meant by absolute entropy?

An engine operating between $150\,^{\circ}C$ and $25\,^{\circ}C$ takes $500\,J$ of heat from a higher temperature reservoir. If there are no frictional losses,the work done by the engine is.....$J$.

According to the second law of thermodynamics,which of the following is true for a spontaneous process?

One mole of $NaCl$ $(s)$ on melting absorbed $30.5 \ kJ$ of heat and its entropy increased by $28.8 \ J \ K^{-1}$. The melting point of $NaCl$ is ............. $K$.

Among the following processes,for which process is the change in entropy $(\Delta S)$ negative?

The standard molar entropy of $H_{2}O_{(l)}$ is $70 \ J \ K^{-1} \ mol^{-1}$. Will the standard molar entropy of $H_{2}O_{(s)}$ be more or less than $70 \ J \ K^{-1} \ mol^{-1}$?