Asample of a compound of mercury and bromine with a mass of 0.389 g was found to contain 0.111 g bromine. its molecular mass was found to be 561. what are its empirical and molecular formulas?

Hello!

1) To get the empirical formula, we'll need to do the following:

First, we'll need to determine the mass of mercury (Hg) using the following equation:



Now, we calculate the moles of each atom, using atomic masses:



To finish, we express the formula using the moles, and dividing each amount by the lower one (0,001386 mol):



2) To calculate the molecular formula, well need to do the following:

First, we calculate the molecular mass of the empirical formula:



Now, we divide the molecular mass of the compound between the molecular mass of the empirical formula to know how many empirical formulas are in the molecular formula:



To finish, we multiply the coefficients in the empirical formula by the number we just calculated to get the molecular formula:



Have a nice day!