What is the name of #K_2CrO_4#?

2 Answers
May 7, 2016

#"Potassium chromate"#

Explanation:

This is a bright yellow salt, that is sometimes used to oxidize organic species. The transition metal oxidation state is (of course) #VI+#.

May 7, 2016

Potassium chromate.

Explanation:

You're dealing with an ionic compound, so right from the start you know that you should identify the cation, which is the positively charged ion, and the anion, which is the negatively charged ion.

You should be able to recognize the fact that the compound contains potassium, #"K"#, an alkali metal that forms #1+# cations, #"K"^(+)#.

The anion is actually a polyatomic ion made up of one chromium atom, #"Cr"#, and four oxygen atoms, #"O"#. This ion is called a chromate anion and it carries an overall #2-# charge, #"CrO"_4^(2-)#.

http://www.wikiwand.com/en/Potassium_chromate

To write the name of this compound, start with the cation, which is the potassium cation, and end with the anion, which is the chromate anion. You will thus have

#"K"_2"CrO"_4 -># potassium chromate

Potassium chromate is yellow in color, both is solid form

https://en.wikipedia.org/wiki/Potassium_chromate

and in aqueous solution

http://www.chem.uiuc.edu/webfunchem/chromate/shift.htm