When performing a flame test using the method described in the manual, you complete the flame test of KNO3 and find a yellow color instead of the expected purple color. Select the potential sources of error. Group of answer choices The nichrome wire is not hot enough. The solution is not concentrated enough. The flame is not optimized. The nichrome wire is dirty. The solution is contaminated. The watch glass is dirty.

The nichrome wire is dirty.

The solution is contaminated.

Explanation:

If the nichrome wire is dirty, it may contain sodium contaminants which may be responsible for the yellow flame. The nichrome wire is first inserted into the flame without the sample to check for impurities.

The test solution may also have been contaminated. This leads to the appearance of a colour different from the expected colour of the test cation in the solution.