A compound has an empirical formula of #HCO_2# and a molecular mass of 90 grams per mole. What is the molecular formula of this compound?

1 Answer
Feb 25, 2016

Answer:

The molecular formula is always a multiple of the empirical formula: #("empirical formula")_n ="molecular formula"#.

Explanation:

So #(1.00794 + 12.011 + 2xx15.999)*g*mol^-1xxn# #=# #90*g*mol^-1#.

We solve for #n#, and clearly #n# #=# #2#.

So empirical formula is #C_2H_2O_4#.