# If you make up a solution of 100mL of 0.1M HEPES in the basic form, what will be the pH

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### Biochemistry

If you make up a solution of 100mL of 0.1 M Hepes in the basic form, what will be the pH? pKa = 7.55

### Biochem

HEPES, is a commonly used component of physiological buffers. The PKa of the protonated amino group of HEPES is 7.55 at 25C. Describe the preparation of 1.00L of 0.100M HEPES buffer, pH 8.00, from the sodium salt of the basic form of HEPES (MW 260.3), .0M HCL and deionized water

### Biochemistry

Sorry! HEPES, is a commonly used component of physiological buffers. The PKa of the protonated amino group of HEPES is 7.55 at 25C. Describe the preparation of 1.00L of 0.100M HEPES buffer, pH 8.00, from the sodium salt of the basic form of HEPES (MW 260.3), 6.0M HCl and ...

### biochemistry

If you make up a solution of 100 mL of 0.1 M HEPES in the basic form, what will be the pH? I have no idea where to even start...

### BioChemisty

You have a 0.5 M HEPES pH 7, and a 0.5 M HEPES pH 8 solution. How much of each stock solution do you need to make 125mL of a 50 mM HEPES pH 7.5 solution? How much water?

### chemistry

The pKa of HEPES is 7.55 at 20 degrees C, and its MW is 238.31. Calculate the amounts of HEPES in grams and of 1.0 M NaOH in milliliters that would be needed to make 300 mL of 0.2 M HEPES buffer at pH 7.2.

### science(chem)

The pKa of HEPES is 7.55 at 20C and it's MW is 238.31. Calculate the amounts of HEPES in grams and of 1.0M NaOH in ml that would be needed to make 300ml of 0.2M HEPES buffer at 7.2. I'm not sure how to go about doing this problem. Help please.

### Math

What volume, in ml, of a 60% of HCl acid solution must be added to 100 ml of a 30% HCl solution to make a 36% HCl solution. We need 2 alegabreic (?) equations. The first I can get is: 0.36x - 0.60y = 100ml (this is probably wrong)? Blah. I can't get the other one. -.- VolHCL*....

### Chemistry

An experiment calls for 100ml of 0.1M copper(II) sulfate solution. Write a step-by-step procedure for a science teacher to make 100ml of 5M stock solution and the required diluted solution.

### Chemistry

can anyone help me with this question A solution is made by dissolving 0.078g of Ca(OH)2 in water to make 100ml of final solution. Calculate the pH of the solution im not sure about how to use the 100ml. thanks -nad You need the 100 ml to determine concentration of OH ion. ...

### Chemistry

How to prepare 10% sucrose solution enriched with 0.1% phenylalanine? And also how to make the stock solution of phenylalanine for the above process. I have prepared 10% sucrose solution by adding 10g sucrose in 100ml water , but how do i make 0.1% phenylanine in 10% sucrose ...

### Chemistry

If you start with 200 ml of 0.1M HEPES buffer (pH 7.5) and add 1.25 ml of 0.5M HCl, what will the final pH be? (The pKa of HEPES is 7.5)

### chemistry

I have already posted this and never got a response, please help. here is my data from lab: Buffer1: HPO4- weight 3.412g; original pH Buffer 2: HEPES wt: 1.090g original pH 10.08 buffer1: pH of 0.1M: 7.5; pH of 0.01: 7.72; pH of 0.001M: 7.87 buffer2: PH of 0.1M: 7.5 ph of 0.01...

### Chemisty

a)What is the [Ca2+] when 100mL of .05M CaCl2 is added to 100mL of .10M K2SO4? b) What is the [SO42-] for part a? c) write the Ksp expression for CaSO4 d)Will a precipitate form in the solution from part a)?

### chemistry

calculate the osmotic pressure of a solution obtained by mixing 100ml of 0.25M solution of urea and 100ml of 0.1m solution of cane sugar at 293k

### chemistry

100ml solution made up 1.0M NH3 and (NH4)2SO4 have been added with 100ml of 0.1 HCl. how many moles are present in the solution before and after? given the pH of the solution is 9.26

### chemistry

A salt solution can be acidic, basic, or neutral. when dissolved in water, which of the following salts will make the solution basic: KCl, FeCl3, NaNO3, CaCO3, LiF, and NH4Br?

### chemistry

The administration of 100mg or more of morphne (molar mass 283) to a patient would be lethel. which of the following would you consider to be a safe dose. a. 100ml of a 20 percent solution (w/v) b. 50ml of a 2 M solution c. 25ml of a 10g/100ml solution d. 0.5ml of a 1M ...

### tough pH problem #2 possible solution

Using the HH equation. pH = pKa + log (base/acid) . I chose pH of 7.45 because I want to minimize the amount of Hepes I have to use so making the pH higher will mean less HEPES would have had to be added originally.. plug in pH of 7.45 and pka of 7.55 and solve for the base/...

### Biochem

We will need 0.5L extraction buffer with 25 mM HEPES, 1 mM EDTA, and 1 mM DTT. Please calculate how many grams of each solute are needed. (HEPES 238.3; EDTA 292.2; DTT 154.2)

### College General Chemistry

How would you prepare each of the following solutions? a. 100mL of a 155ppm solution of urea, CH4N2O, in water. b.100mL of an aquaneous solution whose K+ concentration is 0.075M

### Chemistry

Use the ion-electron method to write and balance the net ionic equation for each of the following reactions. MnO41- + Sn(OH)31- MnO2 + Sn(OH)62- in basic solution MnO41- + (COOH)2(aq) Mn2+ + CO2(g) in acidic solution I2(aq) + S2O32- I1- + S4O62- Zn(s) + HgO(s) ZnO(s) + Hg(l) ...

### science - chemistry pH problems

Here is the hint I received on how to solve those tough pH problems I posted earlier: Both of these can be solved using the H-H and doing the algebra. The math itself is hard to type out, but in Q1 the values of [NaA] and [HA] are 0.04805 and 0.15195. In Q2 you will have to ...

### Chemistry

If 100ml of 1M NaOH solution is added to water make a solution of 1.5L, calculate its normality

### Chemistry

30g of the palm shell were mixed with 15ml H3PO4 and 100ml of distilled water in a 250ml conical flask.The concentration of H3PO4 solution was 2.2M, from question,how to prepare those from ortho phosporic acid (98g/mol).Do help me, is it need to make a stock solution first and...

### chemistry

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### chemistry

A hydrochloric acid So of concentration 1mol/l and a solution S1 of concentration C1= 2×10^-2 mol/l to be prepared from So. The available materials are given below: ● Volumetric pipet: 5ml, 10ml, 20ml ● Beakers: 100ml, 250ml, 500ml ● volumetric flask : 100ml, 500ml ● ...

### biology lab

26.2g of sodium chloride(NaCL) are dissolved in enough water to make 100mL of solution. What is the molarity of this solution?

### Analytical chemistry

0.6140 grams of sodium phosphate (Na3PO4) was dissolved in 2 L of water to make a stock solution. 34 mL of this solution is then diluted to 100mL volumetrically to prepare the final solution. Calculate the molarity of phosphate ions in this solution. Answer to 5 decimal places.

### chemistry

estimate the mass of BaSO4 that will be produced when a 100ml of a 2M solution of Ba(NO3)2 in water is added toa 100ml of a 2M solution of NaSO4 in water

### chemistry (Pls Bob check for me)

A 150mg/dl glucose solution was diluted 1:2. Then 0.5ml of it was added to 4.5ml saline. 2ml of this solution was diluted to 10ml. What is the final concentration of glucose? 1L = 10dL 1dL = 100mL My own calculation 150mg/dL = 150mg/100ml =1.5 150mg/100ml x 1/2 x 1/10 x 1/5 1....

### Chemistry

A 1N solution of NaOH is diluted 4/20 then rediluted 1:50. What is the final normality? How many grams of NaOH are present in 100ml of the final solution? I sort of understand the basic concept, but I don't really know how to do normality problems.

### chemistry plz help!!!

are the following true for the element gallium? if they are false make them true. oxide more basic than Al203 oxide less basic than Mg(OH)2 hydroxide soluble in acid hydroxide soluble in base sulfide precipitates with H2S sulfide not soluble in (NH4)2S will form EaCl3, Ea2S3, ...

### chemistry

are the following true for the element gallium? if they are false make them true. oxide more basic than Al203 oxide less basic than Mg(OH)2 hydroxide soluble in acid hydroxide soluble in base sulfide precipitates with H2S sulfide not soluble in (NH4)2S will form EaCl3, Ea2S3, ...

### Biology

You have a stock solution of 100mg/100ml methylene blue and you need 6.0 ml of final solution at 2mg/100ml. Design a serial dilution using volumes between 0.1 and 10 ml. Final volume must be 6ml.

### Chemistry

How many grams of solid KOH must be added to 100ml of a buffer solution which is 0.1M each with respect to the weak acid HA and its potassium salt KA in order to make the pH of the solution 6.0?

### chemistry

How do you make a 100mL solution of 1.50 M of NaCl.

### chemistry lab

determine the amount of solute needed to make 100ml aqueous solution of NaCl and MgCl2 that will cause a 10 degree change in freezing point. Determine the amounts of solute needed to make 100ml aqueous of AlCl3 and ethanol that will cause a 10 degree change in boiling point.

### Chemistry

In which solution (acidic, basic, neutral water, or doesn't matter) is sodium acetate most soluble? acidic solution Basic solution neutral doesn't matter I already tried basic solution and got it wrong.

### chemistry

determine the amount of solute needed to make 100ml aqueous solution of NaCl and MgCl2 that will cause a 10 degree change in freezing point. Determine the amounts of solute needed to make 100ml aqueous of AlCl3 and ethanol that will cause a 10 degree change in boiling point.

### Chemistry

Which of the following mixtures of KCl in water is a saturated solution and which is an unsaturated solution; 1)100g of KCl in 100mL of H2O at 40°C 2)50g of KCl in 100mL of H2O at 70°C 3) 120g of KCl in 100mL of H2O at 60°C My data is: Temperature82°C 58°C 39°C 18°C 16...

### chemistry

The administration of 100mg or more of morphne (molar mass 283) to a patient would be lethel. which of the following would you consider to be a safe dose. a. 1ml of a 1 percent solution (w/v) b. 1ml of a 0.05 M solution c. 1ml of a 100ml/mg solution d. 0.5ml of a 1M solution e...

XeO3 + I- ----> Xe + I2 (acidic solution) CN)2 -----> CN- + OCN- (basic solution) MnO2 + SO32- ---> Mn2+ + S2O62- (acidic solution) H2SeO3 + H2S -----> S + Se (acidic solution) Cl2 ---> Cl- + ClO3- (basic solution) ClNO2 -----> NO3- + Cl- (acidic solution)

### Chemistry

If 36 g of potassium chloride are dissolved in 100mL of water at 40 C to form a saturated solution, how many grams of potassium chloride would be required to form a saturated solution in 250 mL of water at the same temperature?

### Chemistry

Which of the following solution has greater density? 1. 100ml of saturated aqueous solution of Lif. (Ksp(Lif)=1.84*10^-3). 2. 100ml of saturated aqueous solution of Hg2F2. (Ksp(Hg2F2)=3*10^-6). (We can assume that adding the dissolved doesn't change the volume of the solution...

### chemistry

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### chemistry

Isotonic saline is a 0.9%(g/100ml) solution of salty water. You are asked to make up 2 Litres of isotonic saline. How much salt should you weigh out? Is this right? 0.9g/100ml * 2000ml = 18g of salt should be weighed out.

### chemistry

need help with a question calculate the concentration of grams of sodium stearate per milliliter of diluted solution. To do this, multiply the concentration of sodium stearate in the dishwashing liquid by the dilution of the solution(1.50 ml dishwashing liquid per 100ml ...

### science(chem)

Commercial hydrazine is sold as a 64% solution. Using that as your starting material, how would you prepare a 5% solution of hydrazine? well if it is sold as 64% solution would that mean that it has 64g of hydrazine per 100ml of solvent(water)? and what they want in the end is...

### Basic Chemistry

What is the molar concentration of Na+ in a solution prepared by dissolving 100.0g of Na3PO4 in sufficient H20 to form 2.00L of solution??

### chemistry

How many mL of 5.00% (w/v) solution are needed to make 100mL of physiologic saline (0.90%(w/v) sodium chloride)?

### chemistry Thank a lot help

100ml of h2s04 solution having molarity 1M and density 1.5g/ml is mixed with 400ml of water. Calculate final molarity of h2s04 solution if final density 1.25g/ml. 50ml of 20.8% bacl2 and 100ml of 9.8% h2s04 solution are mixed. Molarity of cl ions in the resulting solution is ...

### chemistry

I'd like to do a titration test, I've got a sulphuric acid solution @ 1M (2N) but I need one @ 0.12N. How many ml of the 1M (2N) solution do I need to add to distilled water to make up 100ml please?

### science

In the lab you need to make 1.00 L of a 0.300 M NaCl solution. You had previously made a 0.950 M NaCl solution that you can dilute to form your new solution. How many mL of the concentrated solution would you use to make the dilute solution?

### science

How many grams of glucose (180g/mole) would be needed to make 100ml of a 1.5 M solution?

### science(chem)

I'm making different concentrations of ethanol and I just wanted to check my calculations and method. Making ethanol concentrations of: 0.40% 0.30% 0.20% 0.10% 0.05% To make the 0.40% ethanol from stock solution using 100ml volumetric flask: (xg ethanol)/(100ml) x 100= 0.40% ...

### AP Chemistry

A buffer solution contains .4mol of formic acid, HCOOH and a .6mol of sodium formate, HCOONa, in 1L of solution. Ka of formic acid is 1.8 x 10^-4. a) calculate pH b) if 100ml of this buffer solution is diluted to a volume of 1L with pure water, the pH does not change. Discuss ...

### chem

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### chemistry

to make 100mL of a solution that is .25M in chloride ion, how many grams of MgCl2 would you need to dissolve

### chemistry

o make 100mL of a solution that is .25M in chloride ion, how many grams of MgCl2 would you need to dissolve

### CHEMISTRY- molality

a sucrose solution was prepared by dissolving 13.5g sucrose in enough water to make 100ml of solution. the density is 1.050gml. calculate molality

### chemistry

The label of a bottle containing a solution So of hydrochloric acid carries the following indications :hydrochloric acid of density 1190g/l percentage by mass 37%. We introduce a volume V=4.2ml of So in a volumetric flask of volume 500ml containing about 100ml of distilled ...

### chemistry

The label of a bottle containing a solution So of hydrochloric acid carries the following indications :hydrochloric acid of density 1190g/l percentage by mass 37%. We introduce a volume V=4.2ml of So in a volumetric flask of volume 500ml containing about 100ml of distilled ...

### CHEMISTRY!

Specifications for lactated Ringer's solution, which is used for intravenous (IV) injections, are as follows for each 100mL of solution: 285-315 mg NA+ 14.1 - 17.3 mg K+ 4.9 - 6.0 mg Ca2+ 368 - 408 mg Cl 231 - 261 mg lactate, C3H5O3 How would you make this solution if you have...

### Chemistry

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### chemistry

100ml of h2s04 solution having molarity 1M and density 1.5g/ml is mixed with 400ml of water. Calculate final molarity of h2s04 solution if final density is 1.25g/ml 50ml of 20.8% bacl2 and 100ml of 9.8% h2s04 solutions are mixed. Molarity of cl ions in the resulting solution ...

### Physical Science

How much Cerium sulfate is needed to make a saturated solution in 100mL of water at 30 degrees Celsius?

### Chemistry

Describe how a buffer behaves. Your description should include an explanation of why the addition of NaOH to the HAc solution formed a buffer. What happens to the pH when a small quantity of a strong acid or base is added to a buffer solution? What happens to the pH of the ...

### Chemistry

a solution of HCL is approximately 0.1M and has to be standardized . 1.234g Na2CO3 are dissolved to make 100ml of solution. 20mL of this solution are titrated with the HCL solution, requiring 31.3mL for the second equivalence point. what is the exact concentration of the HCL ...

### Chemistry

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### college chemistry

In the derivation of this expression: [ln]/[HIn]A# 2 * A#1,acid/A# 2,basic * A#1 We assumed that the HIn form of the indicator is the only form present in the most acidic solution. Is this a valid assumption? Why or why not? Support your answer by determining the ...

### Chemistry

In the derivation of this expression: [ln]/[HIn]A# 2 * A#1,acid/A# 2,basic * A#1 We assumed that the HIn form of the indicator is the only form present in the most acidic solution. Is this a valid assumption? Why or why not? Support your answer by determining the ...

### chemistry

A student placed 19.0g of glucose (c6h12o6) in a volumetric flask, added enough water to dissolve the glucose by swirling, then carefully added additional water until the 100ml.- mark on the neck of the flask was reached. The flask was then shaken until the solution was ...

### Biology

The following chemicals have the indicated formula weight Surcose = 342.3g; Potassium dihydrogen=136.09; and Tris=121.14 Also the following solution already made: 20%SDS, 5M NaCl, 500mM EDTA. You have a 40% glycerol solution, and 10X TBE. List the step to make the following ...

### chem

A student placed 12.5 of glucose (C6H12O6) in a 100ml volumetric flask, added enough water to dissolve the glucose by swirling, then carefully added additional water until the calibration mark on the neck of the flask was reached. The flask was then shaken until the solution ...

### Chemistry

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### chemistry

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### chemistry

I need help getting this started. I made it through organic and this one stumps me, go figure :) How many grams fo NaCl are needed to make 100mL of a 0.10M solution?

### Chemistry

Determine the amount of Sodium Salicylate required to make 100mL of a 0.01M stock solution. {this is from the spectrometric analysis of a commercial aspirin tablet lab}

### Chemistry Lab

So I have a lab exam tomorrow and our instructor said that one of the questions would be as follows: Prepare 100mL of 0.03 M Copper Sulfate, beginning from copper sulfate pentahydrate. Calculate the exact molarity to 3 sig figs. Alright so I understand how to prepare 100mL of ...

### Chemistry

To 1.0 ml of 1.5%NaCl, water is added to a final volume of 100ml. What is the molarity NaCl of this final solution? 1.5g/100ml I do not know where to go from here?

### Chemistry

If 100mL of a 0.10M NaOH solution is added to 75mL of a 0.15 HCl solution, then what is the pH of the resultant solution?

### chemistry

how we prepare a 4M solution of NaCl in 100ml and after this we dillute this 4ml solution to make3.8M solution.

### bio/chem

how do i make percent solutions w/v starting with pure NaCl and distill water. eg 100ml of a 1% NaCl solution

### Lone Peak High

How much of a stock (18.5 M) HCl solution would be required to make 100mL of 0.025 M HCl?

### science

6g of impure NaOH was dissolved in 100ml of a solution.0.25molar solution of the base utilize 27.6ml of the solution containing 6g of trioxonitrate(5)acid.

### Chemistry

How many grams of CaCl2 are needed to make 100ml of a 15% solution in water if only the dihydrated (CaCl2 •2H20) salt is available?

### Chemistry

To what volume must 10ml of 5M HCl be diluted to make a 0.5M HCl solution......???? A.1ml B.50ml C.100ml D.500ml E.1000ml

### Chemistry

You have 100 mL of a 0.450 M sulfuric acid solution, but you now need to add NaOH to make the solution basic. How much NaOH ( in grams) will you need to add to make the solution have a pH of 13.0? The units are grams of NaOH.

### chemistry

Copper can be determined gravimetrically by precipitation as copper(I)thiocyanate, CuSCN. A wrought aluminum-copper sample(4.5167 g) was dissolved in a minimum amount of concentrated HCl followd by the additon of 25 ml of sulfurous acid to reduced the copper. This solution was...

### Organic Chemistry 1

Consider the HF solution with the concentration of 5%(w/v). You can convert the % concentration into the molarity. a) Assume that you have 100ml of this solution. Determine the number of moles of HF if the concentration of HF is given as 5%(w/v) For this part I did 5% is 5g ...

### Chemistry

How many grams of CaCl2 are needed to make 100ml of a 15% solution in water if only the dihydrated (CaCl2⋅2 H2O) salt is available?

### Chemistry 3

How is it possible for me to tell which of these solutes will produce an acidic solution when dissolved in water? LiOH CH3CO2K H2SO3 KOH NaOH NH4NO3 NaOH NaOH can't be the only one... Molecules that produce OH^- when dissolved in water will be basic. Examples:LiOH, KOH, NaOH, ...

### science(chem) Dr.Bob Question from before

I'm doing an experiment and I'm supposed to have neutral basic and acid samples of solution. I just wanted to make sure that I knew which was which. (If I'm incorrect, please correct me) Acid: 0.7ml 10% H2SO4 + 0.7ml 10% Na2WO4(sodium tungstate) Basic: 0.7ml NaOH + saturated ...

### 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 ...

### Chemistry!

Calculate the solubility of Ag2CrO4 in grams/100mL of water? (Ksp = 1.12x10^-12 ) I know how to calcuate the molar solubility, and I know how to convert it into grams/L...but I'm stuck on how to make it grams/100mL Any Help would be awesome! =D thx!

### science

the teacher instructed three students A,B,and C respectively to prepare a 50% (mass by volume) solution of sodium hydroxide (NaOH). 'A' dissolved 50 g of NaOH in 100 ml of water B dissolved 50g of NaOH in 100g of water while C dissolved 50g of NaOH in water to make 100ml of ...

### science

the teacher instructed three students A,B,and C respectively to prepare a 50% (mass by volume) solution of sodium hydroxide (NaOH). 'A' dissolved 50 g of NaOH in 100 ml of water B dissolved 50g of NaOH in 100g of water while C dissolved 50g of NaOH in water to make 100ml of ...

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### Organic Chemistry

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