chem
posted by christine .
When an electric discharge is passed through boron trichloride a new compound is formed. what is its simplest formula if on analysis it is shown to contain .0878 g of chlorine and .0131 g of boron?

Convert grams to moles for each element.
moles = g/molar mass
Then find the molar ratio of the elements to each other with 1.00 being the smallest number used. The easy way to do that is to divide the smaller number by itself (thereby assuring 1.000 for that number), then divide the other number by the same small number. Finally, round to whole numbers and you should have the formula BxCly. Post your work if you get stuck.