The number of degrees of freedom of a five link plane mechanism with five revolute pairs as shown in the figure is:

A rigid insulated cylinder has two compartments separated by a thin membrane. While one compartment contains one kmol nitrogen at a certain pressure and temperature, the other contains one kmol carbon dioxide at the same pressure and temperature. The membrane is ruptured and the two gases are allowed to mix.

Assume that the gases behave as ideal gases. Calculate the increase in entropy of the contents of the cylinder. Universal gas constant equal to $$8314.3$$ $$J/kmol$$ $$K.$$

During the phase change of a pure substance:

At the point of a pure substance, the number of degrees of freedom is :