A person suffering from hyponatremia has a sodium ion concentration

in the blood of 0.118 Mand a total blood volume of
4.6 L.What mass of sodium chloride would need to be added
to the blood to bring the sodium ion concentration up to
0.138 M, assuming no change in blood volume?

2 answers

How many moles Na^+ do we want? That is M x L = 4.6L x 0.138M = ?
How many moles do we have? That is M x L = 4.6L x 0.118M = x
The difference is ?-x = z moles Na^+
Convert z moles Na^+ to moles NaCl (to give z moles NaCl), then
grams = moles x molar mass NaCl.
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