Question

An oxide of chromium is found to have the following composition: 28.2% Cr and 71.8% O. How would you determine this compound's empirical formula?

Answer 1

hello mate..

1. let the weight of given salt as 100g
2. divide the each constituent by their molecular weight
3. divide each mole by least mole to get comparable moles
4. now u have the empirical moles and arrange them no..

• let's start this puzzle..xd.
• for chrochrom 28.2 / 52 = 0.54
• for oxygen 71.8 / 16 = 4.48

1. comparable mass

• for chromium = 0.54 / 0.54 = 1
• for oxygen = 4.48 / 0.54 = 8.29 ~ 8
• so the empirical formula is CrO8