I NEED HELP ASAP ! 1. How many molecules are in 643.21 grams of
Mg3(PO4)22
2. How much space (Liters) does 4.061 x 10-24
molecules of H202 take up?
3. How many H20 atoms are in 479.3 grams of
H20 gas?
4. How many grams does 80.34 L of Ca(NO3)2
weigh?
5. How many Liters of space does 893.7 grams
of CO2 take up?
6. How many grams are in 5139 x10425
molecules of Al(OH)3

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!! :)

we can conclude that the melting point of table salt is above room temperature (it's actually 801 deg c). the melting point of mercury must be below room temperature (- 39 deg c).

the awnser is group 12