As a technician in a large pharmaceutical research firm, you need to produce 450

Question

As a technician in a large pharmaceutical research firm, you need to produce 450. mL of 1.00 M a phosphate buffer solution of pH = 7.31. The pKa of H2PO4- is 7.21. You have 2.00 L of 1.00 M KH2PO4 solution and 1.50 L of 1.00 M K2HP04 solution, as well as a carboy of pure distilled H20 How much 1.00 M KH2PO4 will you need to make this solution? Express your answer numerically in milliliters to three significant figures. Carbon dioxide (CO2) and bicarbonate (HCO3-) concentrations in the bloodstream are physiologically controlled to keep blood pH constant at a normal value of 7.4. Physicians use the following modified form of the Henderson-Hasselbalch equation to track changes in blood pH: where [HCO3-] is given in millimoles/liter and the arterial blood partial pressure of CO2 is given in mmHg- The pKa of carbonic acid is 6.1. Hyperventilation causes a physiological state in which the concentration of CO2 in the bloodstream drops. The drop in the partial pressure of C02 constricts arteries and reduces blood flow to the brain, causing dizziness or even fainting. If the normal physiological concentration of HCO3- is 24 mM, what is the pH of blood if PCO2 drops to 27.0mmHg ? Express your answer numerically using one decimal place.

Explanation / Answer

We have pH of the buffer solution: 7.31 whereas the pKa value of H2PO4- is 7.21.Now from the equation: pH=pKa+log[HPO4--]/[H2PO4-] we have the mole ratio is 1.258925 then the volume needed for making the solution is: the volume of 1(M) KH2PO4 solution needed: (1/1+1.258925)*450 ml= 199.2 ml. For the second part we have pKa=6.1,[HCO3-]=24 mmol and pCO2=27mm Hg then the pH is: 6.1+log[24]/[0.03*27]=7.5717.

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.