Saturday
April 19, 2014

Search: KH2PO4

Number of results: 47

Biochemstry
I got to that part where to find the moles of KH2PO4 but why base/ acid would equal the same. this is how i went about it then i got stuck 11.7 g of KH2PO4/136.08g/mol=.085 mol of KH2PO4 then to find M: 500 ml/1000ml=.5L .085/.5=17 M KH2PO4 then o lost myself
Monday, February 24, 2014 at 6:10pm by James

chemistry
does kh2po4 react with sodium lauryl sulphate and can we use nah2po4 insted of kh2po4 in prepration of 0.2 m phosphate buffer ?
Saturday, May 4, 2013 at 7:45am by jiya

College Chemistry
What is pH buffer of 0.1 mol L-1 Na2HPO4/O.15 mol L-1 KH2PO4? KH2PO4? Given Ka(H2PO4-) = 6.2 x 10-8). I would like to know the correct formula, steps for the answer Thank you
Wednesday, October 20, 2010 at 10:43pm by Helen

chemistry
0.50 mLs of KH2PO4 was diluted to 100 mLs in the volumetric flask. The concentration of the diluted KH2PO4 in the 100.00 mL volumetric flask is: (0.50mLs /100mLs)(Original concentration of KH2PO4). Not sure where the decimal point is in the original phosphate concentration.
Wednesday, July 1, 2009 at 6:27pm by GK

Chemistry
I think your values are correct; you just stopped short of answering the question. You want 0.213 x molar mass KH2PO4 = mass KH2PO4 for the acid and 0.287 x molarmass K2HPO4 = mass K2HPO4 for the base.
Wednesday, October 20, 2010 at 3:57pm by DrBob222

Chemistry
Suppose you have to prepare 1.00 L of the solution ( KH2PO4 and Na2HPO4 pH=7.31) and that this solution must be isotonic with blood (have the same osmotic pressure as blood). What mass of KH2PO4 would you use?
Saturday, March 16, 2013 at 3:16pm by Pepz

biochemistry
Use pH = pKa + log[(base)/(acid)] KH2PO4 is the acid. Na2HPO4 is the base. For b part: Write the reaction between KH2PO4 (the acid) and ethanolamine(the base) and see how much of each is left over and the amount of salt produced. Then plug into the HH equation. Post your work ...
Friday, January 21, 2011 at 7:32pm by DrBob222

biochemistry
if 4 volumes of 0.1M monobasic potassium phosphate, KH2PO4, are mixed with 2 volume of 0.1 M dibasic sodium phosphate, Na2HPO4, what will be the pH of the mixture? What if 4 volumes of 0.1 M KH2PO4 are mixed with 8 volumes of 0.1 M ethanolamine base(pka=9.44) what will be pH ...
Friday, January 21, 2011 at 7:32pm by dIrk

chemistry
As a technician in a large pharmaceutical research firm, you need to produce 200.mL of 1.00 M a phosphate buffer solution of pH = 7.19. 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 K2HPO4 solution, as well as a carboy of pure ...
Saturday, September 14, 2013 at 7:38pm by moses

Chemistry
As a technician in a large pharmaceutical research firm, you need to produce 100.mL of 1.00 M a phosphate buffer solution of pH = 7.45. 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 K2HPO4 solution, as well as a carboy of pure ...
Monday, March 31, 2014 at 1:45am by Billy Bob Reynolds

Chemistry
You need to prepare 1.000 L (in a volumetric flask) of 0.50 M phosphate buffer, pH 6.77. Use the Henderson Hasselbalch equation with a value of 6.64 for pK2 to calculate the quantities of K2HPO4 and KH2PO4 you need to add to the flask. What concentrations of [K2HPO4] and [...
Wednesday, October 20, 2010 at 3:57pm by Anonymous

chem
Calculate [H+] in 0.375M H2PO4 Ka=6.2x10^-8 I know I'm suppose to write the equation first, but I'm not sure if I did it right: H2PO4 + H2O <=> 2H+ + PO4 is that right? You need to clarify the question. Is that a salt, such as KH2PO4, that is 0.375 M or is it the ion ...
Tuesday, May 29, 2007 at 12:19am by Amanda

Chemistry
No, you're mistaken. It is asking for the mass of KH2PO4 and mass K2HPO4 that must be added to the flask to make the 0.5 M buffer. Here is the problem with that part in bold face type and quantities in italics. "You need to prepare 1.000 L (in a volumetric flask) of 0.50 M ...
Wednesday, October 20, 2010 at 3:57pm by DrBob222

Biochemstry
KH2PO4 + KOH ==> K2HPO4 + H2O mols KH2PO4 = 11.7/136.08 = about 0.086 Therefore, base + acid = 0.086 (but you need to do it more accurately). 7.10 = 7.21 + log (base)/(acid) B/A = about 0.8 B+A = about 0.086 Solve the two equations simultaneously for B and A. That will give...
Monday, February 24, 2014 at 6:10pm by DrBob222

chemistry
350 mL KOH x 0.25M= 87.5 mmoles 250 mL H3PO4 x 0.30M = 75 mmoles. ..........KOH + H3PO4 ==> KH2PO4 + H2O initial...87.5...75.0......0........0 change...-75.0..-75.0.....+75.....+75 equil.....12.5....0.......75........75 BUT the KH2PO4 (75 mmoles of it) can react with what ...
Monday, September 26, 2011 at 7:45pm by DrBob222

chemistry
KH2PO4 + KOH ==> K3PO4 + H2O You balance it.
Friday, March 16, 2012 at 12:10pm by DrBob222

Please help Physical pharmacy
How does KH2PO4 induce controlled flocullation?
Tuesday, September 3, 2013 at 9:59pm by jane

Please help Physical pharmacy
How does KH2PO4 induce controlled flocculation?
Wednesday, September 4, 2013 at 11:31pm by jane

physical pharmacy
Hoy does KH2PO4 induce controlled flocculation..?
Thursday, September 5, 2013 at 4:13am by adrian

biochemistry
how to calculate a primary standard buffer using Kh2po4 and Na2Hpo4..
Wednesday, January 9, 2013 at 8:39pm by crazy

Chemistry
What mass of KH2PO4 is needed to prepare 500.0 mL of a 0.067M solution?
Thursday, February 9, 2012 at 7:34pm by John

BIOCHEMISTRY
WHAT METHOD CAN BE USED TO PREPARE 0.2M POTASSIUM PHOSPHATE BUFFER USING KH2PO4 AND KOH?
Monday, February 28, 2011 at 3:35am by MODI

Chemistry
You are to prepare a KH2PO4 and Na2HPO4 solution with pH=7.31. What should the concentration of [2(HPO4) 2-] / [H2PO4-]
Saturday, March 16, 2013 at 3:20pm by Pepz

chemistry
describe an alternative method to prepare a 0.2M potassium phosphate buffer using KH2PO4 and KOH
Sunday, February 27, 2011 at 12:04pm by kabelo

Chemistry--DR.BOB HELP!
If 1 volume of 0.1 KH2PO4 is mixed with 2 volumes of 0.1 OHEtNH2 (pka=9.44), what will be the pH of the mixture? I know I know: HH equation
Saturday, February 5, 2011 at 12:08am by Jimmy

Chemistry
Calculate pH when 0.060 mols of HCl are added to 1.000 L of a buffer containing 0.499M KH2PO4 and 0.193M K2HPO4
Friday, February 10, 2012 at 3:28pm by Jenn

Chemistry
What volume of 85% H3PO4(d=1.68g/mL) and weight of KH2PO4 are required to prepare a buffer of pH=3 that has an ionic strength of 0.2?
Friday, April 13, 2012 at 3:08am by Sam

chemistry
I don't know that you do; however, the problem may be confusing you with the use of pKa (or I suppose it could be confusing me). pK = 7.21 is pK2 for H3PO4 and pK = 12.67 is pK3 for H3PO4. I think you want to use pK2 for H3PO4 and I don't think you need the other one. pK2 for ...
Sunday, November 14, 2010 at 12:36am by DrBob222

chemistry
complete KH2PO4(aq)+KOH(aq)
Friday, March 16, 2012 at 12:10pm by jeff

Chemistry
Calculate the pH of a buffer solution obtained by dissolving 16.0 g of KH2PO4(s) and 27.0 g of Na2HPO4(s) in water and then diluting to 1.00 L. (pKa=7.21)
Thursday, March 29, 2012 at 2:41pm by Jematormal91

chem
I posted a question earlier that I was having trouble with, but I was unable to attempt to try it again for several days after posting. The question was: A buffer is made up of .300 L each of .500 M KH2PO4 and .317 M K2HPO4. Assuming tha the volumes are additive, calculate a) ...
Saturday, May 5, 2007 at 8:25pm by James

College Chemistry
What is pH of the buffer 0.1 mol L-1 Na2HPO4/0.15 mol L-1 KH2PO4? (Given Ka(H2PO4-)=6.2x10 power-8). Sorry if the power is confusing. My computer does not have the symbol. Thanks
Friday, October 22, 2010 at 1:19am by Elleni

chemistry
I don't know that you can. K2HPO4 is a solid. The volume taken up by a solid depends upon particle size. Technically, if you follow the question really close, there is no K2HPO4 is a teaspoon or a tablespoon. Metals or plastic, yes. KH2PO4, no.
Tuesday, November 6, 2012 at 10:54am by DrBob222

BIOCHEMISTRY
H2PO4^- + OH^- ==> H2O + HPO4^-2 Weigh an appropriate amount of KH2PO4, add an appropriate amount of KOH. You find appropriate amounts by using the Henderson-Hasselbalch equation.
Monday, February 28, 2011 at 3:35am by DrBob222

Chemistry
A buffer is made up of .300 L each of .500 M KH2PO4 and .317 M K2HPO4. Assuming tha the volumes are additive, calculate a) the pH of the buffer b) the pH of the bugger after the addition of .0500 mol of HCl to .600 L of the buffer. c) the pH of the buffer after the addition of...
Tuesday, May 1, 2007 at 8:26pm by James

chemistry
3. a) Calculate the pH of the buffer solution prepared by mixing 40.0 mL of 0.100 M H3PO4 and 60.0 mL of 0.100 M KH2PO4. Given the pKa of H3PO4 is 2.12.
Saturday, March 15, 2014 at 12:01am by Syah

Pharmaceutical Dosage Forms
If there is 1 g KH2PO4 and 1 g K2HPO4 in 100mL of solution, what is the mEq/mL of potassium? The Answer is 0.19mEq/mL. But I need to show work on how to get the answer. Textbook Applied physical pharmacy By Mansoor M. Amiji, Beverly J. Sandmann Chapter 3
Tuesday, November 30, 2010 at 5:20pm by Jay

Chemestry
A 1L of buffer was prepared from 0.15 mole of Na2HPO4 and 0.10 moles KH2PO4. a) What is your pH and what is the pH change that adding of 80.0 mL of 0.100 mol L-1 NaOH cause? b) What happen to the pH after adding 10.0 mL of 1.0 mol L HNO3-1.
Thursday, April 28, 2011 at 10:43am by Margo

chemistry
using the following salts listed below, calculate the moles of acid and conjugate base needed to make 100 ml of 0.50 M, ph 6.5,6.7, and 6.8 phosphate buffer solution. (For H2PO4-, pka=6.64) Salt Molar mass, g/mol KH2PO4 136.09 NaH2PO4*H2O 137.99 Na2HPO4*7H2O 268.09 K2HPO4 174.2
Sunday, October 28, 2012 at 7:32pm by alleyx3

APChem
Hi I tried to understand this but I don't know why the answer is B: Which one of the following pairs cannot be mixed together to form a buffer solution: A) NaC2H3O2, HCl B)RbOH, HBr C) NH3, NH4Cl D) H3PO4, KH2PO4 E) KOH, HF The answer is B but could you explain why? I know its...
Sunday, March 21, 2010 at 10:38pm by Kiki

Chemistry
As a technician in a large pharmaceutical research firm, you need to produce 400. mL of 1.00 M potassium phosphate solution of pH = 7.18. 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 K2HPO4 solution, as well as a carboy of pure ...
Monday, February 28, 2011 at 2:44am by Anonymous

Biochemstry
1. A buffer was prepared by dissolving 11.7 g of KH2PO4 in 400 mL of water, and with the addition of concentrated solution of KOH the pH was adjusted to 7.10. The volume was then adjusted to 500 mL. What are the [PO43-], [HPO42-], [H2PO41-], and [H3PO4]? Use pKa values of 2.12...
Monday, February 24, 2014 at 6:10pm by James

Molecular cell Biology
The following chemicals have the indicated formula weights:Sucrose-342.3,Potassium dihydrogen phosphate(KH2PO40-136.09,Tris -121.14.You also have the following solutions made:20%SDS,5M NaCl,500mM EDTA.You have a 40%glycerol solution and 10X TBE.List the steps to make the ...
Saturday, January 18, 2014 at 9:55pm by Caroline

Chemistry
Calculate the pH of the following buffer solutions: a) a solution made by dissolving 2.733g KH2PO4 and 4.508g K2HPO4 in water to give 250 ml of solution. b)a solution made by mixing 35.00 ml 0.24 M C6H5NH2 with 15.00 ml 0.19 M C6H5NH3CL. The base dissociation constant Kb is 4....
Wednesday, February 8, 2012 at 6:17pm by Karie

Chemistry
A buffer solution of volume 100.0 mL is 0.150 M Na2HPO4(aq) and 0.100 M KH2PO4(aq). Refer to table 1. (a) What are the pH and the pH change resulting from the addition of 80.0 mL of 0.0500 M NaOH(aq) to the buffer solution? pH pH change (include negative sign if appropriate) (...
Tuesday, March 16, 2010 at 11:52pm by Trixie

Chemsitry
A chemist needs to make 50 mL buffer solution with a pH value of 7.25 using the acid/conjugate base pair of KH2PO4 and Na2HPO4 (which has an effective pKa = 6.86). The buffer solution needs to be made so that the total concentration of buffer is 0.10 M (that is, [acid] + [base...
Monday, April 2, 2012 at 11:39pm by Cassandra

chemistry
Online chemistry lab preparing standards help? I was told to prepare some standard for a chemistry lab and here where the instructions: Obtain a solution of known phosphate concentration. In this lab we will use (1.e-002M) potassium dihydrogen phosphate, KH2PO4. Note the ...
Wednesday, July 1, 2009 at 6:27pm by Gweedo8

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