In chemistry experiment it is determined that 4.2 moles of aluminum oxide are needed to completely react with a sample of sodium. How many molecules of aluminum oxide are there in 4.2 moles? After an experiment, 35.6 g of carbon were recovered. How many moles of carbon is this?

Aluminium Oxide = 2.5×10²³ molecules

Carbon = 2.96 moles

Explanation:

1 mole of aluminium oxide contains 6.02× 10²³ molecules, hence 4.2 moles will contain 4.2 ×6.02×10²³ molecules

for carbon, number of moles = Mass/ Molar Mass = 35.6/12.01 = 2.96 mole

  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-

i believe the answer is 5,000