Answer:
62.5 moles of O₂.
Explanation:
We'll begin by writing the balanced equation for the reaction. This is illustrated below:
2C₈H₁₈ + 25O₂ —> 16CO₂ + 18H₂O
From the balanced equation above,
2 moles of C₈H₁₈ reacted with 25 moles of O₂.
Finally, we shall determine the number of mole of O₂ needed to react with 5 moles of C₈H₁₈. This can be obtained as shown below:
From the balanced equation above,
2 moles of C₈H₁₈ reacted with 25 moles of O₂.
Therefore, 5 moles of C₈H₁₈ will react with = (5 × 25) / 2 = 62.5 moles of O₂.
Thus, 62.5 moles of O₂ is needed for the reaction.
Answer:
b
Explanation:
it express the mass no of the element
Answer: 
Explanation:
Firstly, we have to find the Molecular mass of potassium oxide (
):
atomic mass: 39 u
atomic mass: 16 u
molecular mass: 
This means that in 1 mole of there are 
and we need to find how many moles there are in 
:
1 mole of ----- of
----- of
This is the quantity of moles in 73.9 g of potassium oxide
Now we can calculate the number of atoms in 73.9 g of potassium oxide by the following relation:
Where:
is the number of atoms in 73.9g of potassium oxide
is the Avogadro's number, which is determined by the number of particles (or atoms) in a mole.
Then:
This is the quantity of atoms in 73.9g of potassium oxide
The molecular weight of the gas is 5040 g/mol
heres the answer!V = nRT/P = 1 mole x 0.082057 x 352 K / 1 atm = 289 L
