Answer:
1.
643.21g 1 mol 6.022^23
262.87 g 1 mol
= 1.4735E24 [Mg3(PO4)2]
2.
4.061x10^24 1mol 22.4 (L)
6.022^23 1mol
= 151 liters H2O2
3.
479.3g 1 mol 6.022^23
18.02g 1mol
= 1.60E25 H20 atoms
4.
80.34L 1mol 164.1
22.4L 1mol
588.6g Ca(NO3)2
5.
893.7g 1mol 22.4
44.01g 1mol
= 427 L CO2 or 427.4
6.
5.39 x 10^25 1mol 78.01
6.022^23 1mol
= 6980g Al(OH)3
hope this helps!! :)