The following table of properties was printed out for saturated liquid and saturated vapour of ammonia. The titles for only the first two columns are available. All that we know is that the other columns (columns $$3$$ to $$8$$) contain data on specific properties, namely, internal energy $$(kJ/kg),$$ enthalpy $$(kJ/kg)$$ and entropy $$(kJ/kg.K).$$

When saturated liquid at $${40^ \circ }C$$ is throttled to $$ - {20^ \circ }C,$$ the quality at exit will be

In the vicinity of the triple point, the vapour pressures of liquid and solid ammonia are respectively given by
$$\eqalign{ & \ln \,\,P = 15.16 - 3063/T \cr & \,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,and \cr & \ln \,\,P = 18.70 - 3754/T \cr} $$

Where $$p$$ is in atmospheres and $$T$$ is in Kelvin. What is the temperature at the triple point.

A vessel of volume $$\,\,1.0\,\,{m^3}$$ contains a mixture of liquid water and steam in equilibrium at $$1.0$$ bar.Given that $$90\% $$ of the volume is occupied by the steam, find the dryness fraction of the mixture. Assume, at $$1.0$$ bar, $${\,{v_f} = 0.001\,\,{m^3}/kg}$$ and $${\,{v_g} = 1.7\,\,{m^3}/kg}.$$