When 229 J of energy is supplied as heat at constant pressure to 3.0mol Ar(g) the temperature of the sample increases by 2.55K. Calculate the molar heat capacities at constant volume and constant pressure of the gas.

The answer is "".

Explanation:

when it is a constant pressure:

and,  

then,

the enthalpy of formation of water is given as -285.8kj/mol, which states that the enthalpy of formation is negative.

negative enthalpy of formation indicates that the heat is released during the reaction process. the heat is released from reaction to the surroundings the enthalpy is expressed with a negative sign with the energy given out in the reaction process.

the formation of water takes place by giving out heat which is -285.8 kj/mol.