What exactly are you looking for?
This is the balanced equation.
<span>2 C4H10g + 13 O2g ---> 8 CO2g + 10 H2Og</span>
To solve for the number of moles, we simply have to use the Avogadros number which states that there are 6.022 x 10^23 molecules per mole. Therefore:
number of moles = 6.67 X 10^40 chlorine molecules / (6.022 x 10^23 molecules / mole)
number of moles = 1.108 x 10^17 moles
Use the concentration to obtain the moles. I am assuming you mean to write capital M. because little m means molality.
So, first convert the ml into Liters and then into moles, then moles to grams using the molar mass (just adding the values of each atom from the periodic table. )
Molar mass= 12 (12.0) + 22 (1.01)+ 11 (16.0)= 342 grams/mole
300 ml (1 liter/ 1000 mL) x (0.50 moles/ 1 Liter) x (342 grams/ 1 mole)= 51.3 grams
Answer : The number of iron atoms present in each red blood cell are, 
Explanation :
First we have to calculate the moles of iron.

Now we have to calculate the number of iron atoms.
As, 1 mole of iron contains
number of iron atoms
So, 0.0519 mole of iron contains
number of iron atoms
Now we have to calculate the number of iron atoms are present in each red blood cell.
Number of iron atoms are present in each red blood cell = 
Number of iron atoms are present in each red blood cell = 
Number of iron atoms are present in each red blood cell = 
Therefore, the number of iron atoms present in each red blood cell are, 