Sorry, I can't really see the question )-:
The answer is 60.3% magnesium, 39.7% oxygen.
Solution:
The chemical equation for the reaction is 2 Mg + O2 → 2 MgO.
Since magnesium reacts completely with oxygen, it is the limiting reactant in the reaction. Hence, we can use the number of moles of magnesium to get the mass of MgO produced:
moles of magnesium = 14.7g / 24.305g mol-1
= 0.6048 mol
mass of MgO = 0.6048mol Mg(2 mol MgO/2mol Mg)(40.3044g MgO/1 mol MgO)
= 24.376g MgO
We can now solve for the percentage of magnesium:
% Mg = (14.7g Mg / 24.376g MgO)*100% = 60.3%
We also use the number of moles of magnesium to get the mass of oxygen consumed in the reaction:
mass of O2 = 0.6048 mol Mg (1mol O2 / 2mol Mg) (31.998g / 1mol O2)
= 9.676g
The percentage of oxygen is therefore
% O2 = (9.676g O2 / 24.376g MgO)*100%
= 39.7%
Notice that we can just subtract the magnesium's percentage from 100% to get
% O2 = 100% - 60.3% = 39.7%
Answer: 4.52x10²⁴ atoms Li
Explanation: For 1 mole of Li it is equal to the Avogadro's Number.
Solution:
7.5 moles Li x 6.022x10²³ atoms Li/ 1 mole Li
= 4.52x10²⁴ atoms Li
Answer:
Explanation:
ρ =
m
V
=
30.8 gram
34.9 cubic meter
= 0.88252148997135 gram/cubic meter
= 0.00088252148997135 kilogram/cubic meter
