Question

In a hot flame, the emission intensities of the sodium lines at 589.0 and 589.6 nm are greater in a sample solution that contains KCl than when this compound is absent. Suggest an explanation.

Short answer

When there are number of electrons, more electrons could be captured by the sodium which are ionized and result in conversion into atoms. These atoms which are excited, generate light or emit light, resulting in more emission intensities. So, with the presence of potassium chloride, the emission intensities of sodium lines are more.

Step-by-step solution

Given information

In a hot flame, the emission intensities of the sodium lines at $589.0$and $589.6\mathrm{nm}$are greater in a sample solution that contains KCl than when this compound is absent.

Explanation

In a sample containing potassium chloride, KCl, the sodium line emission intensities are higher at $589\mathrm{nm}$and $589.6\mathrm{nm}$. Ionization of some sodium atoms happens at higher temperatures. It is possible to ionize potassium chloride easily when compared to sodium atoms. As a result, both sodium, as well as potassium chloride, generate a lot of electrons.

When there are number of electrons, more electrons could be captured by the sodium which are ionized and result in conversion into atoms. These atoms which are excited, generate light or emit light, resulting in more emission intensities. So, with the presence of potassium chloride, the emission intensities of sodium lines are more.