98 ! will award extra pls answer the following: make the following calculations of properties of gases a. how many moles of so2 are in 745 l at stp? b. what is the volume of 325 moles of n2? c. what is the density of a gas with a molar mass of 78 g/mole? question 18 determine the following formula masses: a. nh4cl b. nahco3 c. c17h18f3no question 19 how many moles are each of the following? a. 270 g kbr b. 397 g li2so4 question 20 calculate the percent by mass of water in the following compounds a. cocl2.6h2o b. pbcl2. 3h2o question 21 how many particles are there in a. 0.2 moles feso4 b. 1.7 moles ch4 question 22 what is the mass of a. 1.7 moles cabr2 b. 0.48 moles n2o question 23 determine the percent composition for the following a. a compound contains 6.2 g c, 4.1 g h, and 15.9 g o b. a compound contains 1.2 moles c and 3.2 moles h