Question

4Al + 3O2 ---> 2Al2O3

The molar mass of O2 is 32.0 g/mol. What mass, in grams, of O2 must react to form 3.80 mol of Al2O3?

A.) 60.8
B.) 81.1
C.) 122
D.) 182

Answer 1

D. 182

Step-by-step explanation:

It is correct on edge

Answer 2

Molar mass of O2 = 32 g/mol

Mass of O2 = ?

4 Al + 3 O2 -----------> 2 Al2O3

3 mol O2 -------------> 2 mol Al2O3
x mol O2 -------------> 3.80 mol Al2O3

2 x = 3.80 * 3

2 x = 11.4

x = 11.4 / 2

x = 5.7 moles of O2

1 mol O2 ------------ 32 g
5.7 moles ------------ y

y = 5.7 * 32

y = 182

answer D

hope this helps!.