to confirm the presence of Fe3+ ion, 2 drops of sodium hydroxide is added after the potassium thiocyanate solution. What would be different about the solution after the addition of sodium hydroxide? (Ignore any possible reaction between NaOH and either Fe3+ or the potassium thiocyanate.
Also after sodium hydroxide is added, the procedure calls to add 4 drops of nitric acid. What does the nitric acid do? (again, the problem tells you to ignore the reaction between HNO3 and Fe3+ or SCN-)
Finally why is the nitric acid added twice as much as NaOH?
Thanks in advance!