Thermodynamics ...

The three thermodynamic states $$P, Q$$ and $$R$$ of a system are connected by the paths shown in the figure given on the right. The entropy change in the processes $$P \rightarrow Q , Q \rightarrow R$$ and $$P\rightarrow R$$ along the paths indicated are $$\triangle S_{P Q}, \triangle S_{QR}$$ and $$\triangle S_{PR}$$ respectively. If the process $$P \rightarrow Q$$ is adiabatic and irreversible, while $$P\rightarrow R$$ is adiabatic and reversible, the correct statement is:

Given the following data:

In which of the following pair of reactions first reaction is spontaneous while second reaction is non spontaneous?

If $$\Delta H> 0$$ and $$\Delta S> 0$$, the reaction proceeds spontaneously when:

Which of the following conditions regarding a chemical process ensures its spontanlity at all temperature?

When a block of iron floats in mercury at $$0^o$$C, a fraction $$k_1$$ of its volume is submerged, while at the temperature $$60^o$$C, a fraction $$k_2$$ is seen to be submerged. If the coefficient of volume expansion of iron is $$\gamma _{Fe}$$ and that of mercury is $$\gamma_{Hg}$$, then the ratio $$k_1/k_2$$ can be expressed as.

Which of the following statements is correct for a reverse process in a state of equilibrium ?

In a constant volume calorimeter, 5 g of gas with molecular weight 40 was burnt in excess of oxygen at 298 K. The temperature of the calorimeter was found to increase from 298 K to 298.75 K due to the combustion process. Given that the heat capacity of the calorimeter is 2.5 kJ$${ K }^{ -1 }$$, the numerical value for the $$\triangle U$$ of combustion of the gas in kJ $${ mol }^{ -1 }$$ is:

A system is taken along paths A and B as shown. If amounts of heat given in these processes are respectively QA and QB, then:

Standard entropy of $${X}_{2},{Y}_{2}$$ and $$X{Y}_{3}$$ are $$60,40$$ and $$50$$ $$J{K}^{-1}$$ $${mol}^{-1}$$, respectively. For the reaction,
$$\cfrac{1}{2}{X}_{2}+\cfrac{3}{2}{Y}_{2}\rightarrow {XY}_{3}.\Delta H=-30kJ$$ to be at equilirbium, the temperature will be: