Distilled water frequently contains dissolved CO_2, mating the pH different from
ID: 510368 • Letter: D
Question
Distilled water frequently contains dissolved CO_2, mating the pH different from the theoretical value for pure water. Would Bus cause the pH of your buffer to be slightly higher or slightly lower than the target pH? Explain Was the pH of the buffer you prepared slightly higher or slightly lower than the target value? The pH of a buffer can be adjusted by added small amounts of HCl or NaOH When of these should be added to your buffer to remedy the problem identified in (a)? Defend your choice. Consider the HClO/ClO conjugate acid/base pair. Consult your text or other source for appropriate acid dissociation constants. The hypochlorite ion is the active ingredient in bleach. NaCIO(aq) Explain why this acid/base pair would be a candidate for a buffer with pH = 7.3 (approximate physiological value). Based on your advice in (a), a researcher used this very buffer in a growth medium (including appropriate food and temperature control) for bacteria that proliferate at physiological pH DE sprite the carefully prepared medium. however, bacterial growth was dismal Explain. Biochemists frequently use -phosphate' buffers in their work. Here, 'phosphate' refers generally to the class of phosphate derived ions: H_2PO_4 HPO_4 PO Which of these ions best represents the conjugate acid in a 'phosphate* buffer at physiological pH? Explain. A buffer used in an experiment was described as 'a 02 M phosphate buffer with pH = 7.25.' Based on the conjugate and you identified in (a), determine the concentration of conjugate acid to this '0.2 M phosphate buffer "Explanation / Answer
Question 1.
If there is CO2 gas dissolved in water, there will occur:
CO2(g) + H2O(l) ---> H2CO3(aq)
which then donates H+ to solution
H2CO3(aq) --> H+(aq) + HCO3-(aq)
therefore, it affects pH and alkalinity
This should decrease pH, therefore, the buffer will be slightly lower the target