Question

The ionization energy of sodium is 495 kJ $mo{l}^{-1}$. How much energy is needed to convert atoms present in 2.3 mg of sodium into sodium ions?

• A. 4.95 J
• B. 495 J
• C. 49.5 J
• D. 0.495 J

Answer 1

Answer: (C)

Ionisation energy: The Minimum energy required to remove most loosely held outer most shell electron in the ground state from an isolated gaseous atom is known as ionization potential.

Here,

No. of moles of sodium $=\frac{2.3\times {10}^{-3}}{23}=0.1\times {10}^{-3}$ mole

So energy needed to convert into ions = $495\times {10}^3(0.1\times {10}^{-3})=49.5$ joule