Internal energy is an example of

Which of the following statements is not correct?

When $50 \ g$ of iron is dissolved in $HCl$ at $25 \ ^\circ C$ in a closed vessel,the work done is calculated to be ..... . The atmospheric pressure is $1 \ atm$. (in $J$)

An ideal gas is allowed to expand against a constant pressure of $2 \ bar$ from $10 \ L$ to $50 \ L$ in one step. Calculate the amount of work done by the gas. If the same expansion were carried out reversibly,will the work done be higher or lower than the earlier case? (Given that $1 \ L \ bar = 100 \ J$)

Which of the following processes is endothermic?

Graphically show the total work done in an expansion when the state of an ideal gas is changed reversibly and isothermally from $(P_i, V_i)$ to $(P_f, V_f)$. With the help of a $pV$ plot,compare the work done in the above case with that carried out against a constant external pressure $P_f$.