Chemical formula for Mercury(II)Chloride, Potassium nitrite, Aluminum hydroxide, Sulfure Dioxide. Let me see if I am right for the ones I completed, okay for Potassium nitrite I put KNO^- and subscript 2 and for Aluminu hydroxide I put AlOH^-.

I also need you to fill in this blank: The formula of a compound may represent the composition of the compound and the mass of ________ mole of that compound

mercury(II) chloride HgCl2
potassium nitrite KNO2 correct.
aluminum hydroxide Al(OH)3
sulfur dioxide SO2

Because it is so much trouble to write the subscripts. we usually just do it this way. HgCl2, KNO2, Al(OH)3, SO2.

If we want to show a superscript, we write a caret (upper case 6), then the number;e.g.,
X3 we write as X^3.

I think on fill in the blank you are looking for the word "one". That is, SO2 tells us that is sulfur dioxide, that written that way is 1 mole of SO2, and 1 mol has a mass of 32(for S) and 32(2x16)for O for a total of 64 grams.Thanks for using Jiskha.