Which of the following symbols represents the heat of reaction at constant volume?

Find the constant external pressure required to expand a gas from $2.5 \ L$ to $4.5 \ L$ if the amount of work done is $500 \ J$ at $298 \ K$. (in $bar$)

Although heat is a path function,heat absorbed by the system under certain specific conditions is independent of path. What are those conditions? Explain.

Three moles of an ideal gas expanded spontaneously into vacuum. The work done will be .............. $Joules$.

Identify the correct statements from the following:
$I$) Work is a path function.
$II$) Enthalpy is an extensive property.
$III$) Lattice enthalpy of ionic compounds can be obtained from Born-Haber cycle.

If the work done by $2 \ mol$ of an ideal gas during isothermal reversible expansion from $5 \ L$ to $50 \ L$ is $-189.1 \ L \ atm$,the temperature of the gas (in $^{\circ}C$) is