Blood plasma has the following composition (milliequivalent per litre.). Calculate its osmotic pressure at `37^(@)C`
`Na^(+)=138,Ca^(2+)=5.2,K^(+)=4.5,Mg^(2+)=2.0,Cl^(-)=105,HCO_(3)^(-)=25,PO_(4)^(3-)=2.2,SO_(4)^(2-)=0.5`,Proteins =`16`, Other =`1.0`

Options

A. 7.47 atm
B. 7.30 atm
C. 7.29 atm
D. 7.40 atm

Answer

A

Explanation

. Since for calculating osmotic pressure we require millimoles/litre therefore
`Na^+=138,Ca^(2+)=5.2/2=2/6,K^+=4.5,`
`Mg^(2+)=2.0/2=1.0,Cl^(-)=105,`
`HCO_3^(-)=24,PO_4^(3-)=2.2/3=0.73,`
`SO_4^(2-)=0.5/2=0.25,"Proteins"=16`,
others = 1.0
Total = 294.18 millimoles/litre = `294.18/1000` = 0.294 moles/litre
Now since `pi` = CST
`= 0.294 xx 0.0821 xx .310 = 7.47 atm`