Premium Essay

Preparation Buffers

In: Other Topics

Submitted By carolamondi
Words 1331
Pages 6

Buffer solutions were prepared and their pH measured to determine their buffering capacity. Three buffer solutions were utilized; an undiluted buffer, a diluted buffer solution with 10ml water and a diluted buffer solution with 18ml water. In the undiluted buffer solution there was minimal pH change with a high of 6.78 and a low of 6.47. In the buffer solution in which 10ml of water was added there was minimal pH change with a high of 6.78 and a low of 6.23. In the buffer solution in which 18ml water was added there was significant change in pH with a high of 6.1 and a low of 2.27.


A buffer solution is a solution that is made up of water and a chemical which gives it unique properties with regard to its pH. The chemical is referred to as buffer agent. The buffer agent resists changes in pH when exposed to bases and acids. The aforementioned property makes it useful in dealing with various chemical accidents, protecting sensitive equipment and balancing internal processes of a number of living things.

A buffer agent dissolved in water makes a buffer solution. It is constituted of (HA) an acid and a conjugate base (A-) mixed in water. Once there exists a chemical balance between HA and A- the addition of any bases or acids will be neutralized. This will result in little pH change of the solution. An increase in HA and A- as a result of the addition of bases or acids decreases the buffering capacity of the solution. This implies that the solution acts as a buffer up to a certain point when it is no longer viable.

Hydrolysis equation relating a buffer agent:

HA (aq) + H2O(l) - H2O+ (aq) + A-(aq)

The acid dissociation constant can therefore be written as:

K=[H2O+][A-]/HA (1)

Rearranging the equation gives:

[H2O+]=Ka [HA]/[A-] (2)

Since pH is given to a good approximation by

pH= -log10[H2O+] (3)


Similar Documents

Premium Essay

Ph Measurement and Buffer Preparation

...pH Measurement and Buffer Preparation Quilao, M.H., Regua, R., Reinoso, L.A., Rojas, K.J., Sabalberino, E.M. Abstract In this experiment, phosphate buffer solution was prepared and the pH of the buffer and samples were determined through different liquid indicators and the pH meter. Also, the buffer capacity of the prepared buffer solution was calculated. The group was tasked to prepare a 250 mL phosphate buffer solution of pH 8.0 using dihydrogen phosphate ion (H2PO4) and primary sodium phosphate monohydrate (NaH2PO4.H2O). With the aid of 6.0 M HCl and 6.0 M NaOH, the pH of the buffer was adjusted while being recorded by the pH meter until it reached the desired pH. Afterwards, the buffer solution was introduced to Colorimetric Determination which used acid-base indicators. The buffer solution changed to color yellow when Thymol and Methyl red were added, blue when Bromophenol blue and Bromocresol green were included, purple for Bromocresol purple, pink for Phenol red and Phenolphthalein, and orange for Methyl orange. Introduction The measurement of the low concentration of hydrogen ions present in any biological process is expressed as pH. pH is used to measure the acidity and alkalinity of a solution. pH involves ionic activity, making it difficult to accurately predict the pH value of a solution. The pH is also known to greatly affect our biological system and any large changes could be dangerous, which is why there is a buffer present within our......

Words: 971 - Pages: 4

Free Essay


...LOVELY PROFESSIONAL UNIVERSITY HOME WORK – I DOA: 9/7/2012 DoS: 9/17/2012 ------------------------------------------------------------------------------------------------------------------- Assignment COURSE- Modern Web Programming Tools and Techniques-I COURSE CODE- CAP618T SUBMITTED BY: SUBMITTED TO: Anil Kumar Miss. MANDEEP KAUR Roll-A24 Reg. - 11013165 Sec- D1R05 Q: 1 Take a JavaBeans Object named “Profession” with properties domain and expertise. Show the use of all 4 scope types on this object. Ans:- You just need to create a domain object as a JavaBeans property and the corresponding getter and setter methods. The framework will automatically initialize the domain object and transfers the form data. The UserAction class contains the following code. Public class UserAction extends ActionSupport { Private User user; Public UserAction() { Public String execute() { Return SUCCESS; } Public User getUser() { Return user; } Public void setUser(User user) { this. user=user; } } To refer the user attributes like name, age etc. we need to first get the user object and then access its properties. For example to access the user's age in the Action you need to use the following syntax. getUser().getAge(); public class User...

Words: 1247 - Pages: 5

Free Essay


...Labs Unit 4 Labs NT1210 8/4/14 Unit 4 Labs Lab Review: 4.1 – Page: 82 and 83 1. To eliminate the crossover issue, lower the amount of equipment and cost. Simplify a network. 2. To increase the maximum distance for a signal. If put after the maximum distance the signal may degrade. 3. The connection and processing speed. It also depends on the number of connections the computer or laptop will allow. Lab Review: 4.2 – Page: 85 1. A. Bend Radius: The minimum radius that a fiber optic cable can be bent without loss of light or impairment. A general rule that it be no less than 15 times the cable diameter B. To not affect a signal sent down the line. 2. The core/Glass Filament, Cladding, Buffer, Strengthener and Outer Jacket. Lab Review: 4.3 – Page: 90 1. Ease of installation, lack of certified fiber optic specialists and changes to the physical design of the network later on. 2. By limiting the devices needed depending on the distance and need of each network. Verify the number of access points needed before the start. Lab Review: 4.4 – Page: 95 1. By selecting a specific layer and testing the health you can definitively say the problem lies either below or above that layer. Example: test the Transport layers health if it is ok you know the problem is in the Application layer. 2 A. B. If the cable is damaged in any way it should be checked. -----------------------...

Words: 255 - Pages: 2

Free Essay

Mda Assay

...CHAPTER 3: METHODOLOGY 3.1 Study Design This research is an experimental study which was conducted to investigate the effectiveness of treatment of Cassia alata as antioxidant effects in cardiovascular system of hyperglycemic rats. The antioxidant activity was tested from the leaf of Cassia alata using its aqueous extract. For this study, 30 Wistar rats weighing between 180 to 200g were used. They were housed in standard cages in a room with a 12 hour light/dark cycle and 50 to 60% relative humidity at a temperature of about 30°C. The animals had fed with standard food and water without limit. This study was conducted in two groups of streptozotocin (STZ) induced diabetic rats in which each group will consist of 15 rats. For the first group of STZ induced diabetic rats had fed with Cassia alata aqueous extract for 20 days meanwhile for the second group of STZ induced diabetic rats had fed with normal saline as a negative control for 20 days. The two groups of STZ induced diabetic had divided into 2 batches. First batch of diabetic rats was consisted of 6 rats for both groups while the second batch was consisted of 9 rats for both groups. All of the rats in two groups had fasted for 12 hour before induced diabetic via STZ injection. After an injection, the rats with level of fasting blood sampling (FBS) above 200 mg/dl will take for further investigation. Henceforth, the treatment was began in which the Cassia alata aqueous extract will administer orally after 48 hour......

Words: 2789 - Pages: 12

Premium Essay

Buffer Lab Report

...Introduction Buffer is a solution that resists a change in pH when bases or acid are added. Solutions that are acidic contain high concentrations of hydrogen ions (H+) and have pH values less than seven. Buffer usually consist of a weak acid, and its conjugate base or a weak base and its conjugate acid. The function of buffer is to resist the changes in hydrogen ion concentration as a result of internal and environmental factor. This buffer experiment is important so that we relies the important of buffer in our life. Besides that, it is also important so that we master the buffer preparation techniques and can conduct the experiment ourselves without anyone to instruct us. Other than that, we got to learn how to operate a pH meter and we...

Words: 1344 - Pages: 6

Free Essay

Buffering Work and Family Conflict

...there for your entire family. Both work and family come with obligations and it is often difficult to prioritize between the two as both are very important and rely on each other. There are certain buffers that help dissipate work and family conflict. One of them is family composition. There is a lot covered under a family’s composition. Having close family and friends nearby can help a single working mother or father or even dual working parents juggle their work and family lives. Extra hands on deck are always a plus with busy families. Depending on the ages of the children of a family, younger children tend to provide more stressors while older children who need less are more stable and can do a lot for themselves which relieves potential stress off the parents. If both parents work, having set chores for each of them is a good way to even the playing field making sure neither parent is more overloaded than the other. A housekeeper would also be a great option to take some of that stress of their shoulders. The traditional gender roles are where the husbands work the long hours and the wives stay at home and take care of the children and do the housework. Sometimes conflict is created because of the work stress that the husband goes through where the wife does not. A good buffer for this is for the wife to enter the workforce as well, even if it’s simply...

Words: 807 - Pages: 4

Premium Essay

Acid Base Buffers

...Acis CHEMICAL REACTIONS: ACID-BASE BUFFERS Short Overview Acids and bases represent two of the most common classes of compounds. Many studies have been done on these compounds, and their reactions are very important. Perhaps the most important reaction is the one in which an acid and base are combined, resulting in the formation of water (in aqueous solution) and a salt; this reaction is called neutralization. A buffer solution is a solution that contains both an acid and a salt containing the conjugate base anion in sufficient concentrations so as to maintain a relatively constant pH when either acid or base is added. In this experiment you will prepare a buffer solution and observe its behavior when mixed both with an acid and a base. You will also compare the behavior with that of solutions containing only the acid. Theory In his theory of ionization in the 1880’s, Svante Arrhenius defined acids are substances which form H+ and bases as substances which form OH- in water. He further defined a salt as a substance other than an acid or base which forms ions in aqueous solution. Such substances are thus capable of producing an electric current and are called electrolytes. The amount of electricity produced is directly proportional to the concentration of ions in solution. With regard to electrolytes we have learned previously that strong acids and strong bases ionize completely, and are therefore strong electrolytes because......

Words: 2786 - Pages: 12

Free Essay

Green Light Accounting

...Greenlight Accounting, LLC [pic] Executive Summary Thorough documentation for individual and small firms is an essential element in financial record keeping and tax filing. Personal income from investments, land, compensations, employment, dividends, and interest can sometimes be an over burdensome task for an individual or family to manage and keep track with throughout the year. For businesses, it’s imperative all transactions be logged with accurate bookkeeping and that taxes stay filed in a timely manner to ensure the efficiency of the organization remains intact. Greenlight Accounting is that face-to-face, personal touch and military friendly accounting firm ready to assist with the most miniscule task associated in the process for all Federal, State and local compliances at low affordable and comparable rates. Expanding this one step further is the benefit of green accounting, which is also a service we will be providing, but one that is considered fairly new to the business world, as well as the accounting arena. Table of Contents I. Background and Green Marketing Product Strategy 4 II. Objectives, Pricing, and Goals 5 III. Strategic Plan 5 IV. Marketing Strategy 7 V. Competitive Analysis 9 VI. Customer Analysis 10 VII. Selling Tactics 10 VIII. Evaluation 11 IX.......

Words: 4688 - Pages: 19

Free Essay


...OSTWALD – DILUTION LAW 1. Calculate the dissociation constant of monobasic acid which is 3.5% dissociated in N/20 solution at 20o C. (6.34x10-5) 2. Calculate the hydrogen ion concentration in 10 liters of 0.1 N solution of an acid having dissociation constant 4.0x10-10 . (6.32x10-6g ion liter-1 ) 3. Nicotinic acid (Ka =1.4x10-5) is represented by the formula HNic. Calculate its percent dissociation in a solution which contains 0.10 mol of nicotinic acid per 2.0 liter of solution. (1.66%) 4. A certain weak acid has Ka=1.0x10-4. Calculate the equilibrium constant for its reaction with strong base. (1010) 5. 0.16 g of N2H4 are dissolved in water and the total volume made upto 500 ml. Calculate the percentage of N2H4 that has reacted with water in this solution. The Kb for N2H4 is 4.0x10-6M. (2%) 6. An aqueous solution of aniline of concentration 0.24M is prepared. What concentration of sodium hydroxide is needed in this solution so that anilinium ion concentration remains 1x10-3M? (Ka for C6H5NH3+ =2.4x10-5M) (10-2M) 7. An aqueous solution contains 10% ammonia by mass and has a density of 0.99g cm-3. Calculate hydroxyl and hydrogen ion concentration in this solution.(Ka for NH4=5.0x10-10M) (9.28x10-13 mol L-1) CALCULATION OF pH ...

Words: 5008 - Pages: 21

Premium Essay


...Preparation of Buffers for Use in Enzyme Studies (by G. Gomori) The buffers described in this section are suitable for use either in enzymatic or histochemical studies. The accuracy of the tables is within ± 0.05 pH at 23 ºC. In most cases the pH values will not be off by more than ± 0.02 pH even at 37 ºC and at molarities slightly different from those given (usually 0.05 M). The methods of preparation described are not necessarily identical with those of the original authors. The titration curves of the majority of the buffers recommended have been redetermined by the writer. The buffers are arranged in the order of ascending pH range. 1. Hydrochloric Acid-Potassium Chloride Buffer. Stocks solutions A: 0.2 M solution of KCl (14.91 g in 1 L) B: 0.2 M HCl 50 mL of A + x mL of B, diluted to a total of 200 mL x 97.0 78.0 64.5 51.0 41.5 33.3 26.3 20.6 16.6 13.2 10.6 8.4 6.7 jun 14, 2004 pH 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 2.0 2.1 2.2 Pag.1 2. Glycine-HCl Buffer. Stocks solutions A: 0.2 M solution of glycine (15.01 g in 1 L) B: 0.2 M HCl 50 mL of A + x mL of B, diluted to a total of 200 mL x 5.0 6.4 8.2 11.4 pH 3.6 3.4 3.2 3.0 x 16.8 24.2 32.4 44.0 pH 2.8 2.6 2.4 2.2 3. Phthalate-Hydrochloric Acid Buffer. Stocks solutions A: 0.2 M solution of potassium acid phthalate (40.48 g in 1 L) B: 0.2 M HCl 50 mL of A + x mL of B, diluted to a total of 200 mL x 46.7 39.6 33.0 26.4 20.3 pH 2.2 2.4 2.6 2.8 3.0 x 14.7 9.9 6.0 2.63 pH 3.2 3.4 3.6 3.8 4. Aconitate......

Words: 2459 - Pages: 10

Premium Essay

Ethical Hacking

...Ethical Hacking 1 Running head: ETHICAL HACKING: Teaching Students to Hack Ethical Hacking: Teaching Students to Hack Regina D. Hartley East Carolina University Ethical Hacking 2 Abstract One of the fastest growing areas in network security, and certainly an area that generates much discussion, is that of ethical hacking. The purpose of this study is to examine the literature regarding how private sectors and educational institutions are addressing the growing demand for ethical hacking instruction. The study will also examine the opportunity for community colleges in providing this type of instruction. The discussion will conclude with a proposed model of ethical hacking instruction that will be used to teach a course in the summer semester of 2006 through the continuing education department at Caldwell Community College and Technical Institute within the North Carolina Community College System. Ethical Hacking 3 Ethical Hacking: Teaching Students to Hack The growing dependence and importance regarding information technology present within our society is increasingly demanding that professionals find more effective solutions relating to security concerns. Individuals with unethical behaviors are finding a variety of ways of conducting activities that cause businesses and consumers much grief and vast amounts annually in damages. As information security continues to be foremost on the minds of information technology professionals, improvements in this area are......

Words: 6103 - Pages: 25

Premium Essay

Albumin Lab Report

...incident light in the angle/direction of the incident light. Most colorimeters and spectrophotometers can measure turbidity with good precision and accuracy. This is the most widely used test as it can be done on most semi auto chemistry analyzers. It can even be done on automated chemistry analyzers. Reagents11,12 Antiserum, Phosphate buffered saline, Polyclonal goat anti-human albumin (variable), Sodium azide (0.95g/L), Buffer, Saline (9g/L), Accelerator and Sodium azide (0.95g/L) were used. Preparation and stability of reagents Reagent preparation: Liquid reagents, ready for use. Stability and storage: The reagents are stable until expiry date when kept at 2-80c. Stability in the instrument is atleast 4 weeks if contamination is avoided. Do not freeze. Procedure Sample/control: Ready for use. Reference curve: Generate a reference curve by successive 1:2 dilutions of the microalbumin standard in saline. Alternatively use the Microalbumin Standard Set. Use saline as zero point. Test: Mix 60 mcL of standard, control(s) and samples with 900 mcL of MAL buffer. Read optical density (OD1) of standards, control(s) and samples at 340 nm. Add 150 mcL of antiserum. Mix and incubate for 5 minutes at room temperature. Read optical density (OD2) of standards, control(s) and samples at 340 nm. Calculate OD’s, plot a standard curve and read the concentration of control(s) and samples. Normal values 0-20mg/L Performances The performance characteristics for the microalbumin-2......

Words: 1917 - Pages: 8

Free Essay

A Hands on Intro to Hacking

...Penetration testing Penetration testing A Hands-On Introduction to Hacking by Georgia Weidman San Francisco Penetration testing. Copyright © 2014 by Georgia Weidman. All rights reserved. No part of this work may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or by any information storage or retrieval system, without the prior written permission of the copyright owner and the publisher. Printed in USA First printing 18 17 16 15 14   123456789 ISBN-10: 1-59327-564-1 ISBN-13: 978-1-59327-564-8 Publisher: William Pollock Production Editor: Alison Law Cover Illustration: Mertsaloff/Shutterstock Interior Design: Octopod Studios Developmental Editor: William Pollock Technical Reviewer: Jason Oliver Copyeditor: Pamela Hunt Compositor: Susan Glinert Stevens Proofreader: James Fraleigh Indexer: Nancy Guenther For information on distribution, translations, or bulk sales, please contact No Starch Press, Inc. directly: No Starch Press, Inc. 245 8th Street, San Francisco, CA 94103 phone: 415.863.9900; fax: 415.863.9950;; Library of Congress Cataloging-in-Publication Data Weidman, Georgia. Penetration testing : a hands-on introduction to hacking / Georgia Weidman. pages cm Includes index. ISBN 978-1-59327-564-8 (paperback) -- ISBN 1-59327-564-1 (paperback) 1. Penetration testing (Computer security) 2. Kali Linux. 3. Computer hackers. QA76.9.A25W4258......

Words: 117203 - Pages: 469

Premium Essay

Sosc 224

...Soil Fertility, Evaluation and Nutrient Management Major contributors to increased agricultural production * Fertiliser use * Plant breeding * Other cultural practises * (planting date, crop density, rotations etc) * Weed and pest control * Irrigation Future Challenges * World population continues to grow * Decrease in productive land due to industrial, residential, transport use and soil degradation * 2 degree increase in temperature over 100 years * Extreme weather conditions * Advances in agricultural production needed to feed population Factors for crop yield * Plant growth and yield are affected by over 50 factors * We cannot control many of the climate factors * Soil and crop factors can be managed for maximum and economical production * Table: major factors affecting yield potential The Law of the minimum * Crop yield is determined by the most limiting factor * Crop yield can only be increased by eliminating the most limiting factor * Yield cannot be increased by increasing the supply of other nutrients and factors * Challenge is to identify the limiting factors and eliminate them Sources of mineral nutrients for plant uptake * Plants take up mineral nutrients from soil solution * Amounts of nutrients in solution are small * Soil solution nutrients are replenished by there in soil/solid form Table: Nutrient dynamics in the soil that affect nutrient supply to plants The......

Words: 283 - Pages: 2

Free Essay

C Programming on Linux

...C Programming on Linux What You Need for This Project * A Kali Linux virtual machine. You could use other operating systems too, if they have a C compiler. Writing the hello.c Source Code In a Terminal window, execute this command: nano hello.c The nano editor opens. Type in the program shown below. #include <stdio.h> main() { printf("Hello World!\n"); } Save your file with Ctrl+X, Y, Enter. Compiling hello.c to Create the hello File In a Terminal window, execute these commands: gcc hello.c -o hello ./hello These commands compile the hello.c program, creating an executable machine language file named hello, and run the hello executable. You should see "Hello World!", as shown below. This program works, but it would be nicer if it greeted you by name, and if it put a couple of newline characters after the greeting to make it cleaner-looking. The next version, hello2, will add these features. Writing the hello2.c Source Code In a Terminal window, execute this command: nano hello2.c The nano editor opens. Type in the program shown below. #include <stdio.h> main() { char name[10]; printf("What is your name?"); scanf("%s", name); printf("Hi, %s\n\n", name); } ...

Words: 1293 - Pages: 6