...Gustavo Duran Per#5 Making Dilutions of Concentrated Solutions Purpose: To make dilutions of concentrated solutions and report their concentration in different ways. Hypothesis: I predict that at least one of the tubes will not change color because of the little concentration it has. Materials: Balance, analytical Balance, tabletop milligram weigh paper, 7.6x7.6 cm weigh boat, 3.5”x3.5” Lab scoops cupric sulfate 5-hydrate Tubes, 15 mL, capped Tube racks for 15mL tubes Deionized water Permanent lab marker pens Tubes, glass, 13x100mm Peg racks for 13x100 mm tubes pipets, 5mL pipet pump, green Spectrophotometer, spectronic 20 D+ Procedure: ● In matrixes similar to those shown in table 3.21 and 3.22, record all your calculations and diagrams. Confirm your calculations with another person’s calculations before you begin. Draw a diagram to show how each sample is diluted. Use the equation to make the calculations. Be sure to make the columns te appropriate width for the material they will contain. ● Label all tubes with the name and concentration of the sample, your initials, and the date. Table 3.21 Dilutions of the 300x stock CuSO4 volume to be made (mL) concentration to be made (x) 5 150x 7 30x 5 15x 5 3x 4 Calculations Volume of stock to use Solution preparation diagram 1x 1. Prepare 25mL of 300-mg/mL CuSO4 solution. Mix well. Do not use previously made solutions. consider this a 300x...
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...particular substance and the quantity of the substance present in the sample or samples, as in this case I have 5 test tubes. The absorption spectrum for cobalt(II)chloride with the color red has a wavelength of 680nm(nanometers). This means that the solution did not absorb a lot of the color red. From the graph we can see that green was absorbed the most which had a maximum wavelength of 551nm(nanometers). Since the green was mostly absorbed, it was not reflected through the sample when hit with light. The absorbance of the cobalt(II)chloride is found first because with that we are able to find out the concentration level by using the formula M1V1=M2V2. For each test tube the concentration levels were different since they each had varying dilutions. After finding the concentration for all 5 test tubes we used logger pro on the computer to create a beer’s law graph. Logger pro then...
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...Title: Counting the Number of Yeast Cells in a Suspension using Haemocytometer Objective: To estimate the number of cells of yeast per mm3 in five different dilutions of yeast suspension. Introduction: Biologists often need to count the density of cells in a liquid. “Density of cells” means “the number of cells per unit volume of liquid”. For example, they might want to find out the density of red blood cells in blood plasma, the density of bacteria in milk, or the population of Paramecium sp. (a protozoan) in water from a pond. The simplest, most convenient and cheapest means of accurately determining the number of cells in a sample is to use a haemocytometer and a microscope. A haemocytometer is a specialised slide that has a counting chamber with a known volume of liquid. The haemocytometer is a device originally designed for the counting of blood cells. It is now also used to count other types of cells as well as other microscopic particles. The haemocytometer was invented by Louis-Charles Malassez and consists of a thick glass microscope slide with a rectangular indentation that creates a chamber. This chamber is engraved with a laser-etched grid of perpendicular lines. The device is carefully crafted so that the area bounded by the lines is known, and the depth of the chamber is also known. It is therefore possible to count the number of cells or particles in a specific volume of fluid, and thereby calculate the concentration of cells in the fluid overall. The haemocytometer...
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...3 Basic plate count techniques for the enumeration of microorganisms 3.1 Introduction Most of the recommendations and guidelines contained in this chapter are taken from American Public Health Association (APHA), as described in the Chapter 6 of the 4th Edition of the Compendium of Methods for the Microbiological Examination of Foods (Swanson et al., 2001). When different from or complementary to those of the Compendium, they were complemented with information and recommendations from ISO 6887-1:1999 and ISO 7218:2007, recommended for performing tests using methods developed by the International Organization for Standardization. Microbiological examination of foods is predominantly based on culturing techniques, to detect and enumerate living microorganisms. In view of the huge variety and multiplicity of groups, genera and species that may be present, a great number of tests are used, and which can be of one of two types: qualitative tests, which are aimed at detecting the presence or absence of the target microorganism(s), without quantifying, and quantitative tests which determine the quantity of the target microorganism(s) in the sample, generally per unit of weight or volume. Each of these tests follow differentiated procedures, which in turn depend on the target microorganism(s), but most of them utilize the same basic microbiological culturing techniques. These techniques are the detection of presence/absence (Chapter 5), the Most-Probable-Number counts (MPN)...
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...WORKING DILUTION PROBLEMS It is a common practice to determine microbial counts for both liquid and solid specimens--suspensions of E. coli in nutrient broth all the way to soil samples and hamburger meat. Most specimens have high enough numbers of microorganisms that the specimen has to be serially diluted to quantitate effectively. The following is a step-by-step procedure to working dilution problems, and includes some practice problems at the end. The purpose can be determination of bacterial, fungal, or viral counts (indirectly). This protocol is specific for bacterial counts (colony-forming units, CFUs), but can be modified for fungi (CFUs) and viruses (plaque-forming units, PFUs for viral counts). A set of serial dilutions is made, a sample of each is placed into a liquefied agar medium, and the medium poured into a petri dish. The agar solidifies, with the bacterial cells locked inside of the agar. Colonies grow within the agar, as well as on top of the agar and below the agar (between the agar and the lower dish). The procedure described above produces a set of pour plates from many dilutions, but spread plates (sample spread on top of solidified agar) can be used also. The agar plate allows accurate counting of the microorganisms, resulting from the equal distribution across the agar plate. This cannot be done with a fluid solution since 1) one cannot identify purity of the specimen, and 2) there is no way to enumerate the cells in a liquid. Bacterial colonies Viral...
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...Serial Dilutions & Antibody Titers CLS 240 May 21, 2014 LABORATORY EXERCISE – WEEK 2 Serial Dilutions Principle A set of dilutions where the dilution factor is exactly the same at each step, is known as a serial dilution. Serial dilutions are commonly used in the clinical laboratory to determine the strength or titer of a particular antibody in patient serum. This information can be used to help diagnose the disease state of the patient, which will help the provider develop an effective treatment plan. Serial dilutions are created with a known quantity of both serum and diluent. When making serial dilutions it is import to ensure the zone of equivalence is maintained. The zone of equivalence is where there are an equal amount of antigens and antibodies within the dilution. If the zone of equivalence is not obtained and there are too many antibodies in the dilution it is known as prozone, whereas too antigens it is known as postzone. Hemagglutination studies use the concentration of antibodies to help diagnose patients. When a patient first becomes ill his/her titer will be low, which is known as the acute phase. In the acute phase the titer is low because the patient has recently become ill and the patient’s body has not had enough time to develop antibodies. It is estimated within 2 weeks the patient will enter the convalescent phase where the titer will become increased, suggesting the...
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...A serial dilution is a series of sequential dilutions used to reduce a dense culture of cells to a more usable concentration. Each dilution will reduce the concentration of bacteria/yeast by a specific amount. So, by calculating the total dilution over the entire series, it is possible to know how many bacteria/yeast it was started with. Procedure: test tube A is filled with 10 milliliters (mL) of a solution. The second test tube B is filled with 9 mL of a buffer. This buffer will serve to dilute the original solution. The buffer is frequently distilled water, but this actually depends on the composition of the solution in test tube A. The solution is then diluted. 1 mL of solution from test tube A is drawn out with a pipette and transferred to test tube B and mix thoroughly. The solution that originally had a volume of 10 ml now has a volume of 1 mL in test tube B. The solution, therefore, has been diluted by a factor of 10. 1 mL of the solution in test tube B is moved to test tube C using the technique described previously and thoroughly mix the contents of test tube C. The solution in test tube C has been diluted by a factor of 100. The solution in test tube B has 1/10 the concentration of the solution in test tube A and the solution in test tube C has 1/10 the concentration of the solution in test tube B. The solution in test tube C, therefore, has 1/100 (1/10 x 1/10 = 1/100) the concentration of the solution in test tube A. This process may be repeated as many times as...
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...|Corps |Aileen Liu |CMA: | |Member: | | | | |Objective 18: SWBAT solve word problems with two-step equations |Knowledge: | | | |Certain words in a word problem can clue us in to the mathematical symbols that| | |A cab ride costs $5 for the first mile and $4 for each additional mile.|relate the values that appear in the word problem. | | |Carlo’s cab ride cost $13. | | | |How many miles was the ride? |Skills: | | |A. 2 |Identify the givens | | |B. 3 |Circle all the values | | |C. 4 ...
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...navigate some of the issues facing bakery owners. Application Practice Answer the following questions. Use Equation Editor when writing mathematical expressions or equations. First, save this file to your hard drive by selecting Save As from the File menu. Click the white space below each question to maintain proper formatting. 1. You have recently found a location for your bakery and have begun implementing the first phases of your business plan. Your budget consists of an $80,000 loan from your family and a $38,250 small business loan. These loans must be repaid in full within 10 years. a) What integer would represent your total budget? The integer is 118,250 b) Twenty-five percent of your budget will be used to rent business space and pay for utilities. Write an algebraic expression that indicates how much money will be spent on business space and utilities. Do not solve. .25(118,250)=u c) How much money will rent and utilities cost? Explain how you arrived at this answer. I solved this problem by converting 25% into a decimal and multiplying it by the total loan amount. d) Suppose an investor has increased your budget by $22,250. The investor does not need to be repaid. Rather, he becomes part owner of your business. Will the investor contribute enough money to meet the cost of rent and utilities? Support your answer, and write an equation or inequality that illustrates your answer. No it does not meet the cost of rent and utilities, it is less than...
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...Mike Henkle QLT1 Task 5 Western Governors University A. Create a story problem using one of the above real-world scenarios as a basis, including realistic numeric values, by doing the following: 1. Describe the real-world problem. I was looking into phone plans and stumbled upon T-Mobile, and I decided that I needed a cell-phone and took a look at the plans. T-mobile had one plan that was 50 dollars a month and is unlimited talk, text and web, T-Mobile also has a plan for 30 dollars a month for 1,500 talk and text minutes. After you go through your allotted 1,500 talk and text time was up, the cost skyrockets up to 10 cents a minute. 10 cents a minute comes out to 6.00 per hour, I thought in my head. I decided that instead of jumping into a decision about phone plans, that I should first go home and do the math. I wanted to figure out which plan was going to be the most cost effective, and which plan would suite my needs the best. 2. Explain all needs (e.g., financial, non-financial, situational) of the hypothetical consumer. The needs include many different factors: • The first and most important factor how much do you use your phone? The breaking point on the problem today is 200 talk or text above the 1500 minute plan and I will be paying less up front but more on the back end which is no good. If I chose the 1500 minute plan, I will not want to be going over the 1500 minutes as then the cost would go up to 10 cents...
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...due for the week Option A: f * h = t a. 9 * 40 = $360 Option B: 150 + f(h-20) = t, for h >=20 b. 150 + 10(40-20) = $350 150 = t, for h < 20 c. 150 = total II. I set the hours to "h", the hourly fee to "f" and the total to "t". a. Option A: This option only has an hourly fee for each hour. The fee is $9 and the amount of hours is 40 so I multiplied the hours by the fee. b. Option B: This option has a flat rate of $150 for the first 20 hours and then an hourly rate of $10 thereafter. For the first equation that refers to over 20 hours, I subtracted 20 hours from the total time, multiplied it by $10, and then added it to $150. For the second equation that refers to any amount less than 20 hours, the total is always going to be $150. III. 9h = 150 9 9 h = 16.67 Set the equations equal to each other for under 20 hours. Divide by 9 to get h = 16.67 – the daycare centers are equal in price at 16.67 hours. This solution point is at (16.67, 150). 9h = 150+10(h-20) 9h = 150+10h-200 -10h - 10h -1h = 150 - 200 -1h...
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...EFFICIENCY LEVEL IN SOLVING POLYNOMIAL EQUATIONS AND THEIR PERFORMANCE IN MATHEMATICS OF GRADE 9 STUDENTS A Thesis Presented to the Faculty of the Teacher Education Program Ramon Magsaysay Memorial Colleges General Santos City In Partial Fulfillment of the Requirement for the Degree Bachelor of Secondary Education Major in Mathematics Armando V. Delino Jr. October 2015 TABLE OF CONTENTS Contents Page Title Page i Table of contents ii CHAPTER I THE PROBLEM AND ITS SETTING 1 Introduction 1 Theoretical Framework Conceptual Framework Statement of the problem Hypothesis Significance of the study Scope of the study Definition of terms CHAPTER II REVIEW OF RELATED LITERATURE CHAPTER III METHODOLOGY Research Design Research Locale Sampling Technique Research Instrument Statistical Treatment CHAPTER 1 PROBLEM AND ITS SETTING Introduction In Mathematics, a polynomial is an expression consisting of variables (or indeterminates) and coefficients, that involves only the operations of addition, subtraction, multiplication, and non-negative integer exponents. Polynomials appear in a wide variety of areas of Mathematics and Science. For example, they are used to form polynomial equations, which encode a wide range of problems, from elementary word problems to complicated problems in the Sciences; they are used to define polynomial functions, which appear in...
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...2 2.1 Introduction to Equations 2.2 Linear Equations 2.3 Introduction to Problem Solving 2.4 Formulas 2.5 Linear Inequalities Linear Equations and Inequalities Education is not the filling of a pail, but the lighting of a fire. — WILLIAM BUTLER YEATS M athematics is a unique subject that is essential for describing, or modeling, events in the real world. For example, ultraviolet light from the sun is responsible for both tanning and burning exposed skin. Mathematics lets us use numbers to describe the intensity of ultraviolet light. The table shows the maximum ultraviolet intensity measured in milliwatts per square meter for various latitudes and dates. Latitude 0 10 20 30 40 50 Mar. 21 325 311 249 179 99 57 June 21 254 275 292 248 199 143 Sept. 21 325 280 256 182 127 75 Dec. 21 272 220 143 80 34 13 ISBN 1-256-49082-2 Source: J. Williams, The USA Today Weather Almanac. If a student from Chicago, located at a latitude of 42°, spends spring break in Hawaii with a latitude of 20°, the sun’s ultraviolet rays in Hawaii will be approximately 249 2.5 99 times as intense as they are in Chicago. Equations can be used to describe, or model, the intensity of the sun at various latitudes. In this chapter we will focus on linear equations and the related concept of linear inequalities. 89 Beginning and Intermediate Algebra with Applications & Visualization, Third edition, by Gary K. Rockswold and Terry A. Krieger. Published by Addison Wesley. Copyright © 2013 by...
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...QLT1 Task 5 A. Create a story problem using one of the above real-world scenarios as a basis, including realistic numeric values, by doing the following: 1. Describe the real-world problem. I was looking into phone plans and stumbled upon T-Mobile, and I decided that I needed a cell-phone and took a look at the plans. T-mobile had one plan that was 50 dollars a month and is unlimited talk, text and web, T-Mobile also has a plan for 30 dollars a month for 1,500 talk and text minutes. After you go through your allotted 1,500 talk and text time was up, the cost skyrockets up to 10 cents a minute. 10 cents a minute comes out to 6.00 per hour, I thought in my head. I decided that instead of jumping into a decision about phone plans, that I should first go home and do the math. I wanted to figure out which plan was going to be the most cost effective, and which plan would suite my needs the best. 2. Explain all needs (e.g., financial, non-financial, situational) of the hypothetical consumer. The needs include many different factors: • The first and most important factor how much do you use your phone? The breaking point on the problem today is 200 talk or text above the 1500 minute plan and I will be paying less up front but more on the back end which is no good. If I chose the 1500 minute plan, I will not want to be going over the 1500 minutes as then the cost would go up to 10 cents a minute or 6.00 per hour. • Is this replacing a work or office phone? If...
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...Week 2 Discussion Algebra review. Please respond to one of the following questions: •Imagine you are tutoring a classmate in the four (4) algebraic processes. Outline each procedure in the process of solving algebraic equations and then try to use your outline as a guide to teach a follow student. •The author of your textbook indicates, “If you add percents, you often obtain incorrect results.” Explain in your own words what kinds of errors contribute to inaccurate percent results. •Determine what makes solving an equation with two (2) variables different than one (1) variable. Week 4 Discussion Simple and compound interest. Please respond to one of the following questions: •Explain methods for calculating credit card interest and your reason for going with a particular method. •What are the factors associated with math that you need to know about in order to obtain a mortgage loan. List at least five (5) factors and provide a rationale for those you selected. •A bottle of water cost one dollar in Chicago. However, the same bottle of water cost five dollars in the Mojave Desert. Consider the definitions of cost and value and explain the difference as to why the bottle of water in the desert might be more valuable. Week 5 Discussion Set operations and Venn diagrams. Please respond to one of the following questions: •Create a story problem that demonstrates how a Venn diagram could be used to illustrate combined operation with sets. •Give two (2) reasons why...
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