Electrolyte questions, not sure on answer

notthereyet0 · Apr 4, 2009

I think the answer to 7 should be "acid" not sure letter, 8 should be buffer, and 12 should be alkaline. Acids give off H+ and therefore you have more acid (as in stomach acid). When combined with bicarb HCO3- it becomes more neutral. That is how the body works for homeostasis, CO2 from lungs make more acidic, and HCO3 from kidneys make more alkaline.

Chemistry is not my strong point but that is my understanding of it. Na or salt is an electrolyte that is responsible for electrolyte balance of the body, it is the major extracellular cation (+ charge) that helps the body repolarize cells, etc. Not used much in pH values as far as my understanding. Good luck!!

midnight*sky · Apr 4, 2009

The poster above me is correct, but I found one more error. # 11 should be active transport (a). Na works to control fluid balance via the sodium potassium 'pump' which is a form of active transport. You chose osmosis, which is the movement of H20 thru a semi-permeable membrane, not Na.

Good luck :) F & E balance can be a monster of a subject!

kacefaceRN · Apr 4, 2009

The answers that I would change are #7-10 and 12.

I think #7 and 8 are tricky because you can see how certain answers would be correct. For example, a buffer can yield H+ ions. However, I think you need to look at the most basic and all-encompassing definition. For that reason, I would choose acid (#7) and base (#8) as the answers.

For #9, you need to think back to basic acid-base reactions.

For #10, pH, by definition, describes the concentration of H+. Bicarbonate can affect pH by decreasing the concentration of free hydrogen ions. However, it is still the concentration of H+ that is measured by pH.

Similarly, #12 asks about changes in pH (or H+ concentration). pH levels can be confusing because they seem to change in the opposite way of what you'd expect. If the amount of hydrogen is decreasing, the pH increases, becoming more alkalotic.

If you have .001 mol/L of H+, you have 1x10^-3 mol/L and a pH of 3.

If you have .0001 mol/L of H+, you have 1x10^-4 mol/L and a pH of 4.

Every 1 point increase in pH shows a 10 fold decrease in the concentration of H+.

I think this link explains these concepts better than I can:

http://www.visionlearning.com/library/module_viewer.php?mid=58

As for #11, I disagree with the previous poster. I think your answer is correct. The sodium-potassium pump is an active transport process that regulates the membrane potential of cells. However, it is osmosis through which sodium affects fluid balance.

Music in My Heart · Apr 4, 2009

#7 = acid, #8 = base

A salt is a PRODUCT of an acid-base reaction... an acid + a base combine to form a salt and water. For example, HCl + NaOH -> NaCl + H20

An acid dissociates to yield hydrogen ions; a base dissociates to yield hydroxide ions.

#10: pH roughly means "proportion of H" What does H mean?

#11: Osmotic pressure regulates fluid balance. Na-ATPase transporters don't transport water across the membranes.

#12: Lots of H ions means low pH means very acidic. Few H ions means high pH means alkaline.

Fermin Hernandez, ADN, ASN, RN · Apr 4, 2009

Don't say pH means proportion of H+ as its inverse log and might mess someone up :)

You should get these concepts down solid for sure OP, as they are pretty fundamental.

But yea, look at 7,8,9,10,12 and good luck :)

Music in My Heart · Apr 4, 2009

Don't say pH means proportion of H+ as its inverse log and might mess someone up :)
You should get these concepts down solid for sure OP, as they are pretty fundamental.
But yea, look at 7,8,9,10,12 and good luck :)

Well, proportion doesn't imply directly or inversely. Strictly speaking, of course, it's not the inverse log but rather the log of the inverse. Regardless, pH relates to hydrogen ion concentration... the more ions, the more acidic and the lower the pH.

Now that I think about it, though, the "p" probably relates more to "power" as in exponents since that's how you clear the logarithm and solve for [H] from the pH. I'd guess it's a German word since they did all the early chemistry and physics.