A 2.65 g sample of a salmon-colored powder contains 0.70 g of chromium, 0.65 g of sulfur, and 1.30 g of oxygen. Its molar mass is 392.2 g. What is the molecular formula for the compund?
Can someone elxplain to me how to do it and what the answer is? It would help me TONS!
Thanks :)
2007-02-07 09:55:38 · 1 answers · asked by nicole :) 1 in Science & Mathematics ➔ Chemistry
Change the mass of each element into moles of each element.
You will have 3 answers. Divide all the answers by the lowest of the three to get a small whole-number ratio. The whole numbers will be your subscripts when writing the empirical formula.
Once you get the empirical formula you add up the weight of the molecule and see if it is the same as the given molar mass.
If the empirical mass is smaller, divide the molar mass given by your empirical mass. This will give you a small whole number. Multiply the subscripts by this small whole number to get the molecular formula.
2007-02-07 10:14:57 · answer #1 · answered by physandchemteach 7 · 0⤊ 0⤋