Question

The distance between the K+ and Cl- ions inKCl is 2.8 × 10-10 m.Find the energy required to separate thetwo ions to an infinite distance apart, assum-ing them to be point charges initially at rest.The elemental charge is 1.6 × 10-19 C and theCoulomb constant is 8.99 × 109 N · m2/C2.1. 709.1 eV2. 8.91 eV3. 101.3 eV4. 5.14 eV5. 6.77 eV6. 4.37 eV

Answer 1

The energy required to separate the K+ and Cl- ions in KCl to an infinite distance apart is approximately 5.14 eV.

Step-by-step explanation:

The energy required to separate the two ions to an infinite distance apart can be calculated using the equation for electrostatic potential energy:

Ucoul = k(Q1Q2/ro)

where Ucoul is the electrostatic potential energy, k is the Coulomb constant (8.99 × 10^9 N · m^2/C^2), Q1 and Q2 are the charges on the ions (elemental charge is 1.6 × 10^-19 C), and ro is the distance between the ions (2.8 × 10^-10 m).

Plugging in the values, we get:

Ucoul = (8.99 × 10^9)(1.6 × 10^-19)(1.6 × 10^-19)/(2.8 × 10^-10)

Simplifying the expression, we find that the energy required to separate the ions is approximately 5.14 eV.