The enthalpies of all elements in their standard states are:

Increase in enthalpy of the surroundings is equal to decrease in enthalpy of the system. Will the temperature of system and surroundings be the same when they are in thermal equilibrium?

Which of the following is an isolated system?

The work done when $2 \ mol$ of an ideal gas expands reversibly and isothermally from a volume of $1 \ L$ to $10 \ L$ at $300 \ K$ is $(R = 0.0083 \ kJ \ K^{-1} \ mol^{-1})$ (in $kJ$)

An exothermic reaction is one in which the reacting substances

The enthalpy of fusion of ice per mole is approximately $...$ $kJ / mol$.