The empirical formula of the metal bromide formed by copper and bromine is determined by calculating the moles of each element and finding the lowest whole number ratio. Upon calculation, the empirical formula of the metal bromide is found to be CuBr.
To determine the empirical formula of the metal bromide formed by copper and bromine, we follow these steps:
Calculate the mass of bromine by subtracting the mass of copper from the mass of the metal bromide: 27.93 g (metal bromide) - 12.37 g (copper) = 15.56 g (bromine).
Convert the masses of copper and bromine to moles by dividing by their atomic masses (approximately 63.55 g/mol for Cu and 79.90 g/mol for Br).
Determine the mole ratio by dividing the number of moles of each element by the smallest number of moles calculated in the previous step.
If necessary, multiply the ratios by a whole number to obtain the lowest whole number mole ratio that is integer-based for both elements.
Performing the calculations:
Moles of copper (Cu): 12.37 g / 63.55 g/mol = 0.1946 mol
Moles of bromine (Br): 15.56 g / 79.90 g/mol = 0.1947 mol
Both elements have nearly the same number of moles (rounded to four decimal places), indicating a 1:1 mole ratio. Therefore, the empirical formula of the metal bromide is CuBr.