Question

What evidence is there from your results that the characteristic color observed for each compound is due to the metal ion in each case? describe an additional test that could be done to confirm that the color is due to the metal ion?

Answer 1

Answer: Sodium gives off a yellow flame. The sodium yeloow flame can obscure the faint lilac flame of potassium. So what you do is perform the test again, holding a square of cobalt glass to your eye to observe the flame. The cobalt glass screens out the intense sodium yellow, and you see the lilac flame of potassium loud and clear.