The heat of reaction at constant pressure is given by

When $2 \ mol$ of an ideal gas undergoes spontaneous expansion in a vacuum,the work done is ...... Joules.

What happens when methane undergoes combustion in systems $A$ and $B$ respectively?

System $A$	System $B$
Temperature rise	Temperature remains same

When $2 \ L$ of an ideal gas expands isothermally into a vacuum to a total volume of $6 \ L$,what is the change in internal energy in $J$? (Nearest integer)

Identify the process that proceeds with no heat exchange between the system and the surrounding.

The formation of water from $H_{2(g)}$ and $O_{2(g)}$ is an exothermic reaction because