A mixture of ideal gases has the following composition by mass:

If the universal gas constant is $$8314$$ $$J/kmol$$-$$K,$$ the characteristic gas constant of the mixture (in $$J/kg$$-$$K$$) is ____________.

$$1.5$$ $$kg$$ of water is in saturated liquid state at $$2$$ bar
$$\left( {{v_f} = 0.001061\,\,{m^3}/kg,\,\,{u_f} = 504.0kJ/kg,\,\,{h_f} = 505\,\,kJ/kg} \right).$$ Heat is added in a constant pressure process till the temperature of water reaches
$${400^ \circ }C\left( {v = 1.5493{m^3}/kg,u = 2967.0\,kJ/kg,\,\,h = 3277.0\,kJ/kg} \right).$$ The heat added (in $$kJ$$) in the process is ________.

A mono-atomatic ideal gas $$\left( {\gamma = 1.67,} \right.$$ molecular weight$$=40$$ $$\left. \, \right)$$ is compressed adiabatically from $$0.1$$ $$MPa,$$ $$300K$$ to $$0.2$$ $$MPa.$$ The universal gas constant is $$8.314$$ $$kJ$$ $$kmo{l^{ - 1}}{K^{ - 1}}.$$ The work of compression of the gas (in $$kJ$$ $$k{g^{ - 1}}$$) is

A frictionless piston-cylinder device contains a gas initially at $$0.8MPa$$ and $$0.015$$ $${m^3}.$$ It expands quasi-statically at constant temperature to a final volume of $$0.030$$ $${m^3}.$$ The work output (in $$kJ$$) during this process will be