Question

of the metal ions tested, sodium produces the brightest and most persistent color in the flame. do you think potassium could be detected visually in the presence of sodium by burning this mixture in a flame? could you detect both with a spectroscope?

Answer 1

It is difficult to identify potassium in presence of sodium because sodium produces the brightest and most persistent color in the flame. If you want to identify the coloring of other metals sodium should be absent. If no sodium is there potassium gives violet color to flame.

But with the aid of a spectroscope we could detect the presence of both ions. If the light emitted by the atoms of a particular element is viewed in a spectroscope, only certain bright-colored lines are seen in the spectrum. A given excited atom emits radiation at only certain fixed wavelengths indicates that the atom can undergo energy changes only of certain fixed, definite amounts. If we examine the emission spectra of these ions with a spectroscope, we find that the emission spectra are composed of a series of lines. The series is unique for each metal. Thus potassium has unique series of lines which is different from that of sodium. There by both can be distinguished from each other