In a gas mixture of He, Ne, and Ar with a total pressure of 8.40 atm, the mole fraction of Ar is if the partial pressures of He and Ne are 1.50 and 2.00 atm, respectively.

1.71

Explanation:

According to Dalton's law, the total pressure is the sum of individual pressures.

Given :

= total pressure of gases = 8.40 atm

= partial pressure of helium = 1.50 atm

= partial pressure of neon = 2.00 atm

= partial pressure of argon = ?

putting in the values we get:

To calculate the vapor pressure of the solution, we use the law given by Dalton, which is:

We are given:

= partial pressure of argon = 4.90

= mole fraction of argon = ?

Putting values in above equation, we get:

Thus the mole fraction of Ar is 1.71

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.