Calculate the mass of NaCl needed to bring sodium concentration to 0.139 M

A person suffering from Hypothermia has a sodium ion concentration in the blood of 0.114 M and a total blood volume of 5.1 L. What mass of sodium chloride needs to be added to the blood to bring sodium ion concentration up to 0.139 M? (assuming no change in blood volume)

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Atomic weight of Na: 230 g

Mass of sodium in blood:
230 x 0.114 M = 26.22 g

Mass of sodium needed:
230 x 0.139 = 32.97
32.97 - 26.22 = 5.72 g

5.72 g of sodium needed

Ratio of mass in NaCl
Mass of Cl : Mass of Nacl
35.453 g : 230 g
1 : 6.49

Mass of Cl in NaCl when Na is 5.72 g:

230/35.453 = 5.72/x
230x = 5.72(35.453)
230x = 202.79
x = 202.79/230
x = 0.88g


Mass of NaCl needed:
0.88g + 5.72g
= 6.6 g



Mass of NaCl needed 6.6g


Is this correct?

Woah, man. First off, the atomic weight of Na is 22.99.
If the concentration of Na in the blood is 0.114 M and there is 5.1 L of blood, the mols of Na can be calculated:
0.114 M = mols / 5.1 L
=0.5814 mols of Na in the blood initially.

Now we need to calculate the amount of mols of Na necessary to reach the desired concentration of Na, 0.139 M in the same 5.1 L of blood.
0.139 M = mols / 5.1 L
=0.7089 mols of Na needed in the blood to reach the final desired concentration.

Now take the final amount of mols and subtract the initial amount to determine how many mols of Na must be added.
0.7089 mols final - 0.5814 mols final = 0.1275 mols needed

0.1275 mols Na * 22.99 g/mol Na = 2.93 g Na