Blood is buffered by carbonic acid and the bicarbonate ion. Normal blood plasma

Question

Blood is buffered by carbonic acid and the bicarbonate ion. Normal blood plasma is 0.024 Min HCO?3 and 0.0012 M H2CO3 (pKa1 for H2CO3 at body temperature is 6.1).

Part A

What is the pH of blood plasma?

I got 7.4 for pH which is the correct answer

Part B

If the volume of blood in a normal adult is 5.0 L, what mass of HCl could be neutralized by the buffering system in blood before the pH fell below 7.0 (which would result in death)?

Part C

Given the volume from part B, what mass of NaOHcould be neutralized before the pH rose above 7.8?

Express your answer using two significant

Explanation / Answer

a) pH=pKa+log(salt/acid)

=6.1 + log(0.024/0.0012)

=7.4

b)when HCl is added, the base form (salt form ) reacts to give back carbonic acid. so let the number of moles of HCl added be x.so,

pH=pKa+log(Salt/acid)

or 7=6.1+ log((0.024*5 - x)/(0.0012*5 + x))

or x=0.008 moles

so mass=0.008*36.5

=0.29565 grams

c)let the moles of NaOH be x.so, in this case, the acid reats to give the base form.so,

7.8=6.1+ log((0.024*5 + x)/(0.0012*5 - x))

or x=0.0035 moles

so mass= 0.0035*40

=0.14 grams

Related Questions

Navigate

• Browse (All)
• Browse B
• Subjects