Answer:
The student could have make use of cobalt glass.
Explanation:
Flame test is one of the preliminary test that is done in the laboratories during the identification of chemical species. By using flame test, the particular chemical specie can be identified by its color.
From the question, it is given that the flame test the student did gave the same color that is shades of red for different compounds that he or she tested(wants to identify).
There are two possibilities; (1). All the chemical species that the student wants to identify are the same and (2). The chemical species could have mixed together (contamination).
For the second possibility which is the main problem, the student could have make use of cobalt glass for filtering.
