A buffer solution (more precisely, pH buffer or hydrogen ion buffer) is an aqueous solution consisting of a mixture of a weak acid and its conjugate base, or vice versa. Its pH changes very little when a small amount of strong acid or base is added to it. Buffer solutions are used as a means of keeping pH at a nearly constant value in a wide variety of chemical applications. In nature, there are many systems that use buffering for pH regulation. For example, the bicarbonate buffering system is used to regulate the pH of blood, and bicarbonate also acts as a buffer in the ocean.
I missed this question on an exam and I was wondering if anyone can explain to me how to do it.Homework Statement
The pKa of acetic acid, HC2H3O2, is 4.76. A buffer solution was made using an unspecified amount of acetic acid and 0.300 moles of NaC2H3O2 in enough water to make 2 Liters of...
Homework Statement
What is the H3O+ concentration with the following scenario
5.3e-2M HCl and 7.70e-2 M NaC2H3O2
Homework Equations
Kw = Kb(Ka) ICE tables
The Attempt at a Solution
Both solutions 100% dissociation
The HCl should be fully neutralized giving 7.70e-2 - 5.3e-2 = 0.024M of...
I read somewhere that HNO3 and CH3COONa can act as a buffer solution. I know that the following solutions can act as a buffer-
1) A solution of weak acid and its salt with a strong base.
2) A solution of strong base and its salt with a strong acid.
3) A solution of a salt of weak acid and a...
This isn't really a homework problem. In lab we had an unknown buffer solution and we had to to titrate it with NaOH and HCl to try to identify what the buffer is. In the end I got my pka value equal to 4.52 I can't identify the buffer. My Ka is 3E-5 and I can't match any Ka values to this. Did...
Homework Statement
What is the pH of a carbonate buffer solution prepared by mixing 1.500 mol Na2CO3 and 1.000 mol NaHCO3 and adding water to make a 1.000 L solution? (pKa of (HCO3)- is 10.32)
A 200.00 mL sample of 1.000 M nitric acid was added to the buffered solution above. What is the...
[b]1. The problem is need to prepare 400.0 mL of a .200M buffer having a pH of 7.69
Given .5 M of dihydrogen Phosphate at pKa of 6.82
[b]2. Equation to work from is Henderson-Hasselbalch pH=pKa-log of (A-)/(HA)
where (A-) is weak acid and (HA) is the conjugate base
[b]3. I...
Homework Statement
Hi, I really don't get how to calculate the pH of a buffer solution...I mean I know that the pH of a solution is the negative log of the H3O+ concentration but I don't know how to get to that part...here's the problem...and I would appreciate if someone could actually...
am really stuck on this problem, can't seem to get to the right answer
Homework Statement How many mL of a 3.00 M HCO3- solution must be added to 200 mL of a 0.200 M CO32- solution to make a buffer with pH = 10.30?
Answer. 13.96 mL
Homework Equations
pKa + log([base]/[acid])=pH
HCO3(-) -->...
I know that buffer capacity is defined as the ability of a buffer to resist pH change. I'm trying to calculate the buffer capacity of my buffer. I added NaOH to it until a significant change in pH, usually about 2 units. So when I calculate, should I do
exp. buffer capacity = (moles NaOH /...
Problem:
I need 750mL of an acetic acid-sodium acetate buffer with pH = 4.3. Solid sodium acetate (CH3COONa) and glacial acetic acid are available. Glacial acetic acid is 99% CH3COOH by mass and has a density of 1.05 g/mL. If the buffer is to be 0.25M in CH3COOH, how many grams of CH3COONa...
Homework Statement
To prepare 1M phosphate buffer pH7.8. pKa=7.21. How much molar of Na2HPO4 and NaH2PO4 to be added
I have no confidence in my answer... Can anyone pls have a check?Homework Equations
pH=pKa+lg (base/conjugate acid)The Attempt at a Solution
7.8=7.21 +lg (a/b)
0.59=lg (a/b)...
Question:
What is the pH of a solution made by mixing 0.30 mol NaOH, 0.25 mol Na2HPO4, and 0.20 mol H3PO4 with water and diluting to 1.00L?
My work:
So I found that the Ka value of H3PO4 is 7.5*10^-3 and the Ka value of HPO4 (found in Na2HPO4) is 4.2*10^-13. Because Ka of HPO4 is so small...
First off how exactly do weak acid strong base reactions work. Let's say I have 1 mole of a weak acid HA in a litre of water and let's say for every 4 undissociated molecules 1 molecules dissociate. So I have about 0.2 moles of H+ ions in this solution then I add some KOH let's say 0.5 moles. I...
Finding volume needed for buffer (URGENT!)
Homework Statement
What volume of 0.50M NaClO must be added to 0.20M HClO in order to prepare 500mL of a NaClO/HClO buffer with pH=7.00. Ka(HClO)= 3.5e-8
Homework Equations
I'm using the H-H equation pH=pKa + log ([A]/[HA])
NaClO being A...
Homework Statement
"Calculate the minimum concentrations of formic acid and sodium formate that are needed to prepare 500.0 mL of a pH 3.80 buffer whose pH will not change by more than 0.10 unit if 1.00 mL of 0.100 M strong acid or strong base is added."
Ka of formic acid = 1.8E-4
pKa of...
good / bad ideas:
1. have an extra fridge. small 170 litres. can i use it like an ac - cool the room? switch it on and leave the door ajar?
2. buy five-six 15x15 feet white canvas, put it on my roof. put 2-3 buckets of water on roof. canvas acts as a buffer between main roof and sun. water...
Homework Statement
Prepare 500ml acetic buffer with a concentration of 1 M and a pH o 6.0. (pKa for acetic acis is 4.76; molecular weight for actetic acid is 60g/mol and for sodium acetate is 136g/mol)
Homework Equations
The Attempt at a Solution
I have tried the Henderson...
I am really confused about how to approach the following question. Can someone please help me out?
A buffer is made by mixing CH3COO- and CH3COOH of the same concentration of 0.5M. If the volume of the former is v1 and the latter is v2, show algebraically that the following will always hold...
I have a relatively simple problem. I'm used to making Tris buffer and always use the HH equation to figure it out initially for my ratio of acid/salt in percentage for my given pH.
This is not working for phosphate buffers and really getting me frustrated right now. I know i could just use a...
Homework Statement
You add 100 mL of 1 M H3A
and 4 mL of 5 M NaOH all in 896mL water
Ka=6.309x10^-10
What is pH of solution made?
H3A+H2O---->H2A-+H3O+ Homework Equations
ka=[h2a][H+]/[H3A]
The Attempt at a Solution
Concentrations initially:
[H3A]=100mL * 1 M / (896+4+100) mL = 0.1 M H3A...
I have no idea how to find the pH of a buffer solution:
Please step by step!
Calculate the pH after 0.020 mol NaOH is added to 1.00 L of:
a mixture containing 0.100 M HONH2 and 0.100 M HONH3Cl
please step by step instruction so I can follow and do other problems on my own! Thanks
This isn't homework. It's for my job. I'm supposed to be making a 50mM phosphate buffer to pH 7.2, 0.5 NaOH. I have access to salts, K2HPO4 (dibasic), KH2PO4 (monobasic), and NaCl. I've determined that I need two liters of buffer solution. I did the calculations but when I measured the pH after...
Homework Statement
If you began with 8.5 mL of 0.35 M NaHCO3, how many mL of 0.10 M HCl would you need to add to get a pH 7 buffer?
Homework Equations
pH = pKa + log([base]/[acid]) or pH = pKa + log(mmol base/mmol acid)
The Attempt at a Solution
I have tried making a reaction table, but I...
Hi ! i am new to these forums.. so i just want to ask whether i am posting my query in the correct forum??
I have a doubt regarding this weak acid - weak base buffer.
When the moles of Acid > Base,
We use the formula pH = pka + log10 ([salt]/[acid]) to calculate the pH of the Acidic Buffer...
Buffer solutions are supposed to be made of weak acid and its conjugate base or weak base and its conjugate acid. BUT: weak base has a strong conjugate acid and vice versa.
So I could make a buffer solution from Cl- ions (really weak base) and HCl (conjugate acid). But that's the same as...
Homework Statement
Describe the preparation of 40 L of 0.0500M phosphate buffer, pH 6.9 starting with 1M solutions of KH2PO4 and K2HPO4. pKa= 7.2Homework Equations
pH= pKa + log[A-]/[HA][b]3. The Attempt at a Solution [/b
6.9=7.2 + log[A-]/[HA]
-0.3= log[A-]/[HA]
[A-]/[HA]= 0.50
0.5[HA]=...
Hello!,
I have encountered a problem relating to buffer solutions. The question states that I am to make a Sodium Acetate buffer solution of 0.25mol l-1, at pH 6.8. The reagents used to make the buffer solution however, is Acetic acid and Sodium Hydroxide. The pKa of Acetic acid is given as...
First off, this is not school related as my semester just ended and I've just been playing around with my fpga.
My problem is that I'm trying to write to the ram module then read from it. I understand a little of the tristate buffer and inout signal but we didn't really go over this in class...
Homework Statement
If the initial buffer pH is 4.45, what is the pH when 1.00 mL NaOH is added to 35 mL of water?
Also, if 0.0 mL NaOH is added, what is the pH then?
Homework Equations
The Attempt at a Solution
I have no idea how to do this...all i can think of is to change the pH...
I have a 0.2M solution of Sodium Acetate, (which surprisingly seems to be at pH7.8, (we calculated it should be around pH9)). We then add Cadmium Sulfate, and adjust the pH using acetic acid to pH5. However, when I add the Cadmium Sulfate the pH drops.
Surely this can't happen?
Homework Statement
Consider 1L of a solution that is 0.100 M in acetic acid and 0.100 M in sodium acetate. What will the pH be, when 0.0900 mol of sodium acetate are added?
Ignore changes in volume.
acetic acid pka = 1.75 E-5
Homework Equations
HA --> H+ + A-
pH=pka +log A-/HA...
Hello!
I think this is going to be one of those unread questions that disappear into the abyss, so I'll shorten in hopes of a reply:
What exactly does this mean: "If the reaction is carried out in a glycine/hydrazine buffer pH0.9, then pyruvate is trapped as the hydrazone and H+ the buffer."?
I...
I don't know if its just me, but I think the wording of the question is weird and I'm not really understanding what it is saying. I have stared at this problem for many hours and have even went to the teacher to try to clarify. The teacher provide us with the actual work on how to calculate...
I have a Question that I cannot figure out:
Describe how to make a buffer with pHs of 4.2, 7.3, and 9.7. For each buffer, you will need to choose a different method. For ex., if you make a buffer using a conjugate pair, you cannot reuse this method for the other 2 buffers...
I just...
If you add HCl to a buffer solution of HF/NaF, the F- will react with H+ to produce HF. THe new pH can be calculated with the henderson-hasselbach equation. My question is, if F- decreases and HF increases, why and how does [H+] change?
HF <> F- + H+
Thank you.
given .1M of formic and .1M formate, how do you make 40 ml of .1M Buffer ph=2.9
basically it's going to equal .141=\frac{base}{acid} after going through henderson hasselbach
Does anyone know how to do this using an ICE table?
I was wonder how I might go about making a buffer solution.
I plan to choose an acid and conjugate base (or vice versa) for my chosen pH using the Henderson-Hasselbach equation. But, let's say I choose acetic acid. Should I just pour some acetic acid into a volume of water and let equilibrium...
[SOLVED] pH of buffer solution
Homework Statement
Calculate the pH of a solution made by mixing 750 mL 1.00 M NH4+Cl and 250 mL 1.00 M NaOH
The Attempt at a Solution
NH4+ will react with H2O to form NH3 and H2O+. If my calculations are correct, [H+] after the reaction will be 2.07E-5...
Which pair of solutions forms a buffer solution when equal volumes of each are mixed?
a. 0.20 M HCl and .20 M NaOH
b. 0.40 M HC2H3O2 and 0.20 M NaOH
c. 0.20 M HCl and 0.20 M NH3
d. 0.40 M HCl and 0.20 M NH3
Thanks
You want to make an acetic acid/acetate buffer, pH 5.6, with a volume of 250 mL, and a final concentration of ([AcOH] + [Aco-]). You may only use acetic acid and sodium acetate( no strong acid or base). How many mL of glacial acetic acid would be needed( d=1.05g/mL)?
New here, hello :)
Which of following mixtures will be a buffer when dissolved in a liter of water?
a. .1 mole of Ba(OH)2 and .2 mole of HBr
b. .3 mole of KCl and .3 mole of HCl
c. .4 mole of NH3 and .4 mole of HCl
d. .2 mole of CH3COOH and .1 mole of NaOH
e. .2 mole of HBr and...
Homework Statement
Buffer solution : CH_3COOH (55 mL) + CH_3COONa (45 mL)
Ka (CH_3COOH) = 1.76 x 10^-5
Calculate the expected pH of your buffer solution after it has been dilted by making 10 mL of buffer up to 100 mL with deionized water.
Homework Equations
Ice charts
n= c x v
c= n/v...
how would you prepare a 100ml of a 0.1M sodium phosphate buffer containing 0.5M NaCl,pH7.6 using henderson hasselbach equation??what chemicals would you use n how would you go about it
Calculate the pH of the 0.30 M NH3/0.36 M NH4Cl buffer system. What is the pH after the addition of 20.0 mL of 0.050 M NaOH to 80 mL of the buffer solution?
NH4+ ---> NH3 + H+
0.36 0.30 0
-x +x +x
0.36-x 0.30 + x x...
[SOLVED] Anticipated pH of Buffer Solution (urgent!)
Homework Statement
Can someone verify my process here? i did a lab where i had 100 mL CH3COOH/CH3CO2- buffer solution. I have to find the pH if 100 mL of 0.0983 M HCl is added to it. In the lab i got pH of 1.72
[b]2. Homework Equations...
Homework Statement
A buffer is prepared by dissolving 1.00 mole HLac (with a ka=8.0x10-3) and 1.00 mole of sodium lactate (NaLac) in enough water to form one (1) liter of solution. Calculate the [H+] and the pH of the buffer.
36 minutes ago - 3 days left to answer.
Additional Details
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