The number of mole of Ca reacted is:
4.86 g Ca/ (40.08 g/mol Ca)= 0.121 mol Ca
Because Ca reacted completely with oxygen and there is 2 mol Ca, there is 1 mol O2 reacted.
Total mass of oxygen that reacted is:
0.121 mol Ca* (1mol O2/ 2 mol Ca)* (32 g O2/ 1 mol O2)= 1.94 g O2 reacted.
Hope this would help~
Pure- table salt
Impure- vegetable oil
Depends on the element it can by up to 3, 8, or maybe 16.
We add up all the various atoms:
C: 55
H: 72
Mg: 1
N: 4
O: 5
55 + 72 + 1 + 4 + 5
= 137
The answer is B.