What is the Empirical Formula of Vitamin B5 (Niacin)?

[Kelly09]

Vitamin B5 is called niacin or nicotinic acid. Its percentage composition by mass is (58.4% Carbon) (4.09% Hydrogen) (25.99% Oxygen) and (11.38% Nitrogen). What is the empirical formula of vitamin B5?

 

[sjb-2812]

Assume you have 100g of niacin. From your percentages, what mass of carbon, hydrogen, nitrogen and oxygen do you have? How many moles of each?

 

[chemisttree]

And Niacin is Vitamin B3, BTW. Minor mistake that won't really affect your problem.