If you divide the molar mass of a compound by the empirical formula mass, what is the result?

That division should be VERY close to a whole number. Usually, 0.9 to 1.1 or 1.9 to 2.1 (all depending upon the accuracy and precision of experimental data). That number is the number used to indicate the units of the empirical formula that are hooked together. For example, the molar mass of acetylene is 26. The empirical formula is CH and the empirical formula mass is 13. So, 26/13 = 2.0 which tells me the molecular formula is two units of the empirical formula. Since the empirical formula is CH, then the molecular formula must be (CH)2 or C2H2. If your "number" isn't EXACTLY a whole number, round it so it is. If it is outside the limits I show above, there must be an error in experimental data or the calculation is wrong. I hope this helps.

Best

When you divide the molar mass of a compound by the empirical formula mass, the result will usually be very close to a whole number. This number is used to indicate the units of the empirical formula that are hooked together to form the molecular formula.

To calculate this, you need to know the molar mass of the compound and the empirical formula mass.

First, find the molar mass of the compound by adding up the atomic masses of all the elements in the compound. For example, let's say the molar mass of the compound is 52 g/mol.

Next, calculate the empirical formula mass by adding up the atomic masses of the elements in the empirical formula. In this case, let's say the empirical formula is XY and the empirical formula mass is 26 g/mol.

Finally, divide the molar mass by the empirical formula mass. In this example, it would be 52/26 = 2.0.

If the result is very close to a whole number, like 0.9 to 1.1 or 1.9 to 2.1, then that number represents the units of the empirical formula that are hooked together. In the example, the result of 2.0 tells us that the molecular formula is two units of the empirical formula XY. Therefore, the molecular formula must be (XY)2 or X2Y2.

If the result is not a whole number, round it to the nearest whole number. If the result is significantly outside the range of 0.9 to 1.1 or 1.9 to 2.1, then there may be an error in the experimental data or the calculation.

I hope this explanation helps! Let me know if you have any further questions.