Question

the empirical formula for trichloroisocyanuric acid, the active ingredient in many household bleaches, is ocncl. the molar mass of this compound is 232.41 g/mol. what is the molecular formula of trichloroisocyanuric acid?

Answer 1

C3Cl3N3O3

Step-by-step explanation:

The "trichloro-" tells us there are 3 chlorines (Cl).

Set up a table of the elements along with their molar masses, See the attached spreadsheet.

By changing the number of each atom, we can calculate the resulting molar mass, shown at the lower right, in green. One can try various numbers for each element in the compound, but understand the chemistry helps.

The 3 Cl atoms add 106.4 g/mole to the total of 232.4 g/mole. I know there are probably 3 carbon atoms, and that adds another 36.0 g/mole. The remaining 90.0 g/mole must consist of N and Cl atoms. 3 N atoms would contribute 42.0 g/mole, leaving 42 g/mole. Oxygen has a molar mass of 16 g/mole, so if we add 3 O atoms, that would make up the remaining 42.0 grams/mole.

This would not be easy to do without more information, but I had a sense for what the structure might look like, and went with those guesses, to arrive at C3Cl3N3O3