How many moles of helium are needed to fill a balloon to a volume of 4.9 at 296°K and 0.78 atm?

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Explanation:

pressure, volume, temperature, and the number of moles, it was clear that a single. atm of pressure within safety limits, how much gas can it safely carry at room. 0.21 atm. Ar has a partial pressure of 0.01 atm. PN2 .78 atm 0.78 moles nN2.

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.