6. This question refers to the compound aluminum sulfate octadecahydrate, Al2(SO4)318H2O. Report your answers to parts (a)-(c) to 2 decimal places. (a) Calculate the formula weight. (b) What is the percent water in the compound? (c) What is the percent oxygen in the compound? (d) How many atoms of hydrogen are present in 1.00g of the compound? Report your answer in scientific notation to 3 significant figures. 7. A compound contains 55.78%C,11.70%H, and 32.52%N. (a) What is its empirical formula? (Report in the format CxHyXz ). (b) If its molar mass is 172.3g/mol, what is its molecular formula