Answer:
Option F. 3moles
Explanation:
The equation for the reaction is given below:
2H2 + O2 —> 2H2O
from the equation,
2moles of H2 required 1mole of O2.
Therefore, 6moles of H2 will require = 6/2 = 3moles of O2
Answer : The moles of
formed are, 22.3 moles.
Explanation : Given,
Moles of
= 16.72 mol
The given chemical reaction is:

From the balanced chemical reaction, we conclude that:
As, 3 moles of
react to give 4 moles of 
So, 16.72 moles of
react to give
moles of 
Therefore, the moles of
formed are, 22.3 moles.
Answer:
0.135 mole of H2.
Explanation:
We'll begin by calculating the number of mole in 3.24 g of Mg. This can be obtained as follow:
Mass of Mg = 3.24 g
Molar mass of Mg = 24 g/mol
Mole of Mg =?
Mole = mass /Molar mass
Mole of Mg = 3.24/24
Mole of Mg = 0.135 mole
Next, we shall write the balanced equation for the reaction. This is illustrated below:
Mg + 2HCl —> MgCl2 + H2
From the balanced equation above,
1 mole of Mg reacted to produce 1 mole of H2.
Finally, we shall determine the number of mole of H2 produced by reacting 3.24 g (i.e 0.135 mole) of Mg. This can be obtained as follow:
From the balanced equation above,
1 mole of Mg reacted to produce 1 mole of H2.
Therefore, 0.135 mole of Mg will also react to produce 0.135 mole of H2.
Thus, 0.135 mole of H2 can be obtained from the reaction.
Answer : The volume of the cube is, 
Solution : Given,
Density of nickel = 
Number of nickel atoms = 
Molar mass of nickel = 58.7 g/mole
First we have to calculate the moles of nickel.
As,
atoms form 1 mole of nickel
So,
atoms form
moles of nickel
The moles of nickel = 3.321 moles
Now we have to calculate the mass of nickel.


The mass of nickel = 194.94 g
Now we have to calculate the volume of nickel.



Therefore, the volume of the cube is, 
i think its theory but im not to sure