The correct answer is oceanic crust, 80 km, Hope this helps let me know.
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~
L

mol/dm³ is measure for molarity
Answer:One mole of HBr has 6.02 x 1
0
23
molecules of HBr.
1 mole of HBr = 6.02 x 1
0
23
molecules of HBr.-----(a)
X mole of HBr has 1.21 x
10
24
molecules of HBr.
X mole of HBr = 1.21 x
10
24
molecules of HBr------(b)
Taking ratio of (a) and (b)
X / 1 = 1.21 x
10
24
/ 6.02 x 1
0
23
X= 2.009 moles.
Explanation: