Answer: 1.
moles
2. 90 mg
Explanation:

According to stoichiometry:
1 mole of ozone is removed by 2 moles of sodium iodide.
Thus
moles of ozone is removed by =
moles of sodium iodide.
Thus
moles of sodium iodide are needed to remove
moles of 
2. 
According to stoichiometry:
1 mole of ozone is removed by 2 moles of sodium iodide.
Thus 0.0003 moles of ozone is removed by =
moles of sodium iodide.
Mass of sodium iodide=
(1g=1000mg)
Thus 90 mg of sodium iodide are needed to remove 13.31 mg of
.
Helium would be the least I think
Answer: The balanced equation for the complete oxidation reaction that occurs when methane (CH4) burns in air is
.
Explanation:
When a substance tends to gain oxygen atom in a chemical reaction and loses hydrogen atom then it is called oxidation reaction.
For example, chemical equation for oxidation of methane is as follows.

Number of atoms present on reactant side are as follows.
Number of atoms present on product side are as follows.
To balance this equation, multiply
by 2 on reactant side. Also, multiply
by 2 on product side. Hence, the equation can be rewritten as follows.

Now, the number of atoms present on reactant side are as follows.
Number of atoms present on product side are as follows.
Since, the atoms present on both reactant and product side are equal. Therefore, this equation is now balanced.
Thus, we can conclude that balanced equation for the complete oxidation reaction that occurs when methane (CH4) burns in air is
.
Answer:
1.204 × 10^24 formula units
Explanation:
Using the following formula to convert mass of iron (III) chloride to moles;
mole = mass/molar mass
Molar mass of FeCl3 = 56 + 35.5(3)
= 56 + 106.5
= 162.5g/mol
Mole = 325/162.5
mole = 2mol
Next, to calculate the formula units of FeCl3, we multiply the number of moles of FeCl3 by Avagadro number (6.02 × 10^23)
Formula units of FeCl3 = 2 × 6.02 × 10^23
12.04 × 10^23
= 1.204 × 10^24 formula units.