The ionisation enthalpy of sodium is 5.14 eV. How many k cal of energy is required to ionise all atoms present in one gram of gaseous Na atoms?

Explanation

`"1 eV atom"^(-1) = "23 k cal mol"^(-1)`
Energy required to ionise all atoms of 23 grams (one mole) of gaseous Na atoms `=23xx"5.14 k cal"`
Energy required for ionisation of all atoms present in one gram of gaseous Na   toms is `(23xx5.14)/(23)="5.14 k cal."`