The pH of blood stream is maintained by a proper balance of H_2 CO_3 and NaHCO_3 concentrations. What volume of 5 M NaHCO_3 solution should be mixed with a 10 mL sample of blood which is 2 Min H_2 CO_3, in order to maintain a pH of 7.4?K_a for H_2 CO_3 in blood is 7.8 xx10^(-7)

The pH of blood stream is maintained by a proper balance of H_2 CO_3 a

1.	The pH of blood stream is maintained by a proper balance of H_2 CO_3 and NaHCO_3 concentrations. What volume of 5 M NaHCO_3 solution should be mixed with a 10 mL sample of blood which is 2 Min H_2 CO_3, in order to maintain a pH of 7.4?K_a for H_2 CO_3 in blood is 7.8 xx10^(-7)
Answer» `50.20 mL` `62.42 mL` `78.37 mL` `52.41 mL` SOLUTION :Let ussupposethe volumeof `NaHCO_3` mixed beV mL ` THEREFORE ` No. of molesof Na`HCO_3`in V mLof 5 M`NaHCO_3` `=( 5 xx V )/(1000)= 0.005 V ` Noof molesof` H_2CO_3 ` in10mLof 2 M`H_2CO_3 = ( 2 xx 10 )/( 1000 ) = 0.02` NowfromHenderson.sequation, `pH = pK_a + log(["SALT "])/(["Acid"])` `7.4 =- log( 7.8 xx 10^(-7 ) ) + log ( 0.005V )/( 0.02)` `7.4 = 6.10 79 +log( 0.005V )/( 0.02)` ` 1.2921= log( 0.005 V )/( 0.02)or( 0.005V )/( 0.02 )= 19.5929` ` thereforeV= 78.37mL`