URGENT Mole Practice 1. How many moles of HCl are in 7.80 X 10^22 molecules?
___0.13 moles of HCI_

2. How many atoms are in 5.6 moles of Na?
3.2 E 24 atoms of Na

3. A chemical reaction produces 3.81g potassium chloride (KCI). How many formula units of
potassium chloride are there?*Find molar mass of KCI
Answer_3.08 E 22 formula units of KCI

4. Calculate the molar mass of Fe2(SO2)3. Then calculate the mass of iron(III) sulfate of 4.05X1023
formula units.
_269g Fe2(SO4)3_

5. Determine the number of liters in 4.32 grams of water (H2O)
__ 5.37LH2O___

  the   balanced   equation   for   reaction of   ca metal   with   o2 to   produce   cao   is as below

2 ca+ o2→ 2 cao2

  explanation

the reaction is   balanced     since the   number of atoms   in reactant side is   equal to   number of atoms   in   product side.   for   example   they   are 2   atom of   ca in   reactant   side   and   2   atoms of ca   in   the product side.

  the   process   is a   meet the   requirement   of   redox   reaction because :     calcium   is   oxidized   from   oxidation state 0   to 2+   while   oxygen   is reduced from   oxidation   state   0   to 2-