<span>pH = pKa + log ([R-]/[RH])
Where pH is the pH of the buffer, [R-] is the concentration of the basic species, and [RH] is the concentration of the acidic species.
At pH 2.4, the amino group on glycine (pKa = 9.6) will be, for accounts and purposes, 100% protonated. This means our buffer will be dealing with the two ionic forms of the carboxyl group (pKa = 2.4).
When pH = pKa, the two species are in equilibrium. This can be seen using the HH equation:
2.4 = 2.4 + log ([R-]/[RH])
0 = log ([R-]/[RH])
1 = ([R-]/[RH])
[RH] = [R-]
Now we add in another equation, our conservation of mass.
M = [RH] + [R-]
where M is the molarity of the buffer
But since [RH] = [R-]:
M = 2 [RH]
0.2 = 2 [RH]
And we wind up with:
[RH] = [R-] = 0.1 M
Now to figure out the moles of each needed, we multiply by the volume of the buffer.
0.1 M * 0.1 L = 0.01 mol
This shows that to make 100 ml of 0.2 M glycine buffer, we'll need 0.01 mol of each species.
0.01 mol of 0.5 M HCl:
0.5 mol HCl / 1 L = 0.01 mol / v
solve for v
v/1 = 0.01 / 0.5 ==> v = 0.02 L or 20 mL
weight of glycine:
MW: 75.07 g/mol
0.01 mol glycine * (75.07g glycine / 1 mol) = 0.75 g glycine
And there's your answer
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To make this buffer you would add 0.75g glycine to 20 mL of 0.5 M HCl and fill with water until a 100mL volume was achieved.</span>
Answer:
Positive space refers to the subject or areas of interest in an artwork, such as a person's face or figure in a portrait, the objects in a still life painting, or the trees in a landscape painting.
Negative space is the background or the area that surrounds the subject of the work. This can be used to empathise the positive space and to create dramatic effect.
Explanation:
Answer:
b. call radio stations
Explanation:
I mean all of them could work, but on the radio people will listen to your music with out having to look for it. Basically they discover you.
Answer: The Cave required a total of 18 musicians and five video screens. <em>The correct answer is A. </em>
Explanation:
The Cave was an opera that had a total of 3 acts. The opera was first played in 1993 in Vienna. The opera was performed by the Steve Reich Ensemble. The opera had both spoken parts that were interviewed by American, Israeli, and Palestinian religious experts. There were also excerpts from the <em>story of Abraham</em> that were in the opera. Images and spoken part were displayed on the screens in the theaters where the opera were performed.
Answer:
I would say to teach wisdom of the India locked in stories, like symbols, rituals, and enhancing all individuals beliefs of that.
Explanation: