Answer:
Grams of Cr that react are 11,05x10*2 g
Explanation:
4Cr + 3O2 → 2Cr2O3
This equation means that 4 moles of Cr, react with 3 moles of O2.
My mass of O2 is 5,1x10*2g but I need to know the moles.
Mass/ Molar mass = Moles
5,1x10*2g /32.00g/mol = 15,9 moles of O2
So the rule of three is
If 3 moles of O2 __ react with __ 4 moles of Cr
15, 9 moles of O2 ___ react with___ ?
(15,9 . 4) /3 = 21,2 moles of Cr.
To know the mass, I have to multipply, the molar mass to the moles.
Molar mass . Moles = Mass
52g/mol . 21,2 moles = 1105 gr.
In scientific notation I can write 11,05x10*2 g
