Question

Ist and IInd IE of Mg are 7.646 and 15.035 eV respectively. The amount of energy needed to convert all the atoms of magnesium into Mg2+ ions present in 12 mg of magnesium vapours is [Given, 1 eV = 96.5 kJ mol–1]

Solution

Correct option is

1.1

 

Total energy required for the conversion of one Mg atom into Mg2+ is = IE1 + IE2

             = 7.646 + 15.035 eV   

             = 22.681 eV   

             = 2188.6 kJ mol–1

  

                         = 0.5 × 10–3   

∴ The energy required to convert 0.5 × 10–3 mol Mg into

Mg2+ = 0.5 × 10–3 × 2188.6

         = 1.09 ≈ 1.1.

SIMILAR QUESTIONS

Q1

Which ionisation potential (IP) in the following equations involves the greater amount of energy?

Q2

The first four ionisation energy values of an element are 191, 578, 872 and 5962 kcal. The number of valence electrons in the element is

Q3

Which one of the following elements has the highest ionisation energy?

Q4

In the Periodic Table, going down in the fluorine group

Q5

The Ist IEs of four consecutive elements present in the second period of Periodic Table are 8.3, 11.3, 14.5 and 13.6 eV respectively. Which of these is the IE of nitrogen?   

Q6

Which of the following transition involves maximum amount of energy?

Q7

 

The formation of the oxide ion O2–(g) requires first an exothermic and then an endothermic step as shown below  

               

                    

This is because 

Q8

The electronic configuration of four elements are given below. Which element does not belong to the same family?

Q9

The least stable ion among the following is

Q10

Which of the following is the most electropositive element?