borane has the em pirical formula BH3 and a molecular mass of 28 amu. What
is its molecular formula?
The empirical formula of borane is BH3, which means it has one boron (B) atom and three hydrogen (H) atoms.
The molecular mass of borane is 28 amu.
To determine the molecular formula, the first step is to find the molar mass of the empirical formula BH3. The molar mass of one boron atom is 10.81 amu, and the molar mass of three hydrogen atoms is 3.03 amu (1.01 amu x 3). Adding these values together, the molar mass of BH3 is 10.81 amu + 3.03 amu = 13.84 amu.
Next, divide the molecular mass of borane (28 amu) by the molar mass of BH3 (13.84 amu):
28 amu / 13.84 amu = 2.02
The result is approximately 2.02, so the ratio of the molecular mass to the molar mass of BH3 is close to 2.
Therefore, the molecular formula of borane is 2 times the empirical formula BH3, which gives the molecular formula of B2H6.