How much does 1.2 moles of koh weight

There are 6.022 x 10^23 atoms of hg in 1 mole of hg. the number of atoms in 4.5 moles of hg can be found by multiplying 4.5 by 6.022 x 10^23 a. 2.7 x 10^24 b. 27 x 10^23 c. 2.71 x10^24 d. 27.099 x 10^23

How many moles of air are there in a human lung with a volume of 2.4 l at stp? explain your answer

What does the mass of 0.7891 mol of ferric oxide (fe2o3)