One of the hydrides of boron has molar mass=122.22g/mol and is 11.55% by mass hydrogen. Determine its molecular formula?
Atomic weight of boron is 10.8 and of hydrogen is 1.
Percentage of mass of boron is 88.45% and of hydrogen 11.55%. Dividing the percentages by the respective atomic masses, we obtain a ratio of boron to hydrogen of 1: 1.4, in integer numbers 5:7. The minimal formula is therefore