Answer those and i have more too!!

1_
How many grams of dinitrogen tetrafluoride must be weighed out to get a sample of dinitrogen tetrafluoride that contains 16.0 g of fluorine ?

2_If a sample of carbon tetrachloride contains 17.5 g of chlorine, how many grams of carbon does it contain?

3_A compound is found to contain 63.65 % nitrogen and 36.35 % oxygen by weight.

What is the empirical formula for this compound?

4_A compound is found to contain 31.42% sulfur, 31.35% oxygen, and 37.23% fluorine by weight.

What is the empirical formula for this compound?

And more