A balloon containing an ideal gas is initially kept in an evacuated and insulated room. The balloon ruptures and the gas fills up the entire room. Which one of the following statements is TRUE at the end of above process?

A rigid, insulated tank is initially evacuated. The tank is connected with a supply line through which air ( assumed to be ideal gas with constant specific heats) passes at $$1$$ $$MPa,$$ $${350^ \circ }C.$$ A valve connected with the supply line is opened and the tank is charged with air until the final pressure inside the tank reaches $$1$$ $$MPa.$$ The final temperature inside the tank.

What is the speed of sound in Neon gas at a temperature of $$500$$ $$K$$ (Gas constant of Neon is $$0.4210$$ $$kJ/kg$$-$$K$$)?

A small steam whistle (perfectly insulated and doing no shaft work) causes a drop of $$0.8$$ $$kJ/kg$$ in the enthalpy of steam from entry to exit. If the kinetic energy of the steam at entry is negligible, the velocity of the steam at exit is