Documents about Unknown Acid
Acid Base Titration
Virginia Tech, CHEM 1045
Excerpt: ... Date performed: Date submitted: Instructor: Name: Partner: Title Objective (be specific for different part) A brief statement of the objective. Main point for the goal of the lab; Experimental Data Part A. Make a table which includes two columns : one is the titration number, like titration 1, titration 2 etc. and show the volume of NaoH you used to titrate in the other column. Part B. Make a table including 4 columns : Sample number, Mass of Beaker, Mass of Beaker with unknown acid and Volume of NaOH used for the titration ; Part C : Make a table similar to the one you make in part B. Notes: Your table style may be different from what is required here. Whatever style you use, the content must be shown clearly enough which makes it easy to understand. Points will be taken off if not clear. Sample Calculation Part A. Calculate the molarity of NaOH solution (remember to show the equation, define the parameters in your equation) Part B Calculate the moles of unknown acid ; Calculate t ...
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Acid-Base Lab
Cornell, BIO 2210
Excerpt: ... Chris Stanton Lab Report: Acid/Base Titration 10/19/06 I. Introduction During this experiment, the goal was to eventually determine the molar mass and pKa of an unknown acid . A series of preliminary steps and data collection is needed before those calculations can be made. First, the base NaOH (approximately 0.1M) is titration with a known acid, KHP. After titration, the exact molarity of the NaOH solution can be determined by using the starting amount of KHP in your sample, the molecular mass of KHP, and the amount of NaOH used. After this, you are ready to begin testing your unknown acid . A preliminary titration is done first to see about how many milliliters of NaOH are needed to titrate approximately 500 mg of your unknown acid . A calculation is then done to predict how much of your unknown acid you would need to use between 30 and 40 mL of NaOH. A series of calculations are then done to produce a table that can guide you through the precise titrations in order to collect accurate data. The precise ...
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chem 208 lab 6
Cornell, CHEM 2080
Excerpt: ... Exp. #6: The Identification of an Unknown Solid Acid Caitlin Burrows TA: Lijun Fan Due: April 20, 2005 Abstract: The purpose of this lab was to correctly identify solid acid by (1) finding the molecular weight of the acid using a known indicator (phenolphthalein) and (2) finding the pKa of the acid using a known volume of solution. We did this experiment in two trials to ensure accuracy. Upon completion, we found that the average molecular weight for our trials was 112.68 g/mol and the average pKa was 3.15. Based on these trials, our acid (#2306) was identified as 2Furoic Acid. Our percent error for the molecular weight was 0.54%, while the percent error for the pKa was 0.44%. Introduction: When given an unknown acid or base, it is possible to calculate the substance's molecular weight and pKa value using acid/base chemistry. Using a method of titration, with an indicator, on is able to exploit the relationship between molarity and volume of a solution to determine the molecular weigh ...
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Chem Exp. Rep. 1
Nevada, CHEM 202
Excerpt: ... 02/10/08 CHEM 202 Experiment Report: Determining the Equivalent Mass and Dissociation Constant of an Unknown Acid by Titrimetry PURPOSE: The purpose of this lab was to measure the pKa of an unknown acid using titrimetry by graphing volume and pH then finding the equivalence point and half-equivalence point of the graph. RESULTS AND DATA: Deter. 1 13.6 .00386 .00386 78.1 Deter. 2 10.1 .00287 .00287 107 92.3 6.80 5.05 5.93 1.58E-7 8.91E-6 4.53E-6 Butyric Acid 4.83 1.48E-5 Volume of NaOH soln required to reach equivalence point, mL # Equivalence of NaOH req. to reach equivalence point # Equivalents of unknown acid titrated, equiv. Equivalent mass of unknown acid , g/equiv. Avg. Equivalent mass of unknown acid , g/ equiv. pKa of unknown acid Avg. pKa of unknown acid Ka of unknown acid Avg. Ka of unknown acid Name of unknown acid Reported pKa of acid named above Calculated Ka of acid named above CALCULATIONS: POST-LAB QUESTIONS: 1.) a.) % Error= 4.76 % b.) % Error=20.2 % 2.) a.) Calculated molarity would be t ...
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Identification of an Unknown Acid
Marquette, CHEM 2
Excerpt: ... Identification of an Unknown Acid April 2nd , 2008 Lab Section 2216 Chemistry 002 Yunyun Wu Rebecca Dermody & Courtney McKenna I. Purpose: The purpose of this lab was to identify an unknown acid by calculating its molar mass, density, melting point, and pH titration. The identity of the unknown was found by comparing the found values to known values of acids. II. Procedure: Fill buret with NaOH Dissolve 0.112 g unknown solid in water Titrate unknown and record pH at every mL Find apparent molar mass Measure physical date o Melt solid unknown acid to determine melting point o Weigh unknown to determine density Find known acids with similar melting points, molar mass, and density Combine unknown acid and known acid and find new melting point III. Observations and Results: Values of Unknown Acid Melting Point 138C Density 1.29 g/mL Molar Mass 132. 64 g/mol pH Titration: NaOH (mL) 1 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0 10.0 11.0 12.0 pH 5.14 5.20 5.23 5.25 5.35 5.48 5.60 5.70 5.87 6.05 6.23 6.40 13.0 ...
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Handout0921
Haverford, CHEM 100
Excerpt: ... Lecture outline for Friday, September 21, 2007 (Chem 100, section 2) Arrhenius definition of acids and bases, and acid-base reactions Acid produces H3O+ when dissolved in water. Base produces OH- when dissolved in water. Sample Problem Unknown acid (2.0000 g) is titrated with 0.4000 M NaOH. Endpoint at 20.0 mL. What is molar mass of acid? pH scale and equilibrium 2 4 3 Le Chatelier's Principle: why NH3 solutions have pH > 7 Bronsted Definition of Acids and Bases, and acid-base reactions 2 6 Acid - H+ donor + Base - H acceptor 8 Water can be Bronsted acid or a Bronsted base 4 Phenolphthalein is a weak Bronsted acid Redox Reactions 2 2 Reductant: Electron donor Oxidant: Electron acceptor 2 Assigning Oxidation Numbers Balancing Redox Metal Activity Series 2 4 Examples of Redox Reactions Fe (SO ) Na PtCl S SF KO HS KH H CrO _ Fe = _ Cl = _ S = _ S = _ K = _ S = _ H = _ H = _ sum=_ ONLINE HW DUE Monday 9/24 ...
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expermient 6
Rochester, PHYS 121
Excerpt: ... ill be taken at 3 intervals 440nm, 518nm, and 576nm. Along with the absorbance the color of each of the three samples will be noted and the results will be compared to known compounds. Conclusion: Because the absorbances match that of a diprotic acid, as seen in the previous lab, along with concurrent color verification we are lead to believe the unknown is some kind of diprotic acid. The coloring is similar in which as it changes from acidic to basic the color changes from yellow to a dark purple. 3) The unknown acid Challenge: Determining the unknown acid Hypothesis: By using the same techniques developed experiment number 1 we can systematically determine the acids used in each solution. Technique: First the unknowns will be tested with HCL, if there is no color change then the substance contains HCL. If there is a change it will then be tested with Bromine, because it is stronger then Iodine. If there is a color change the substance will then be tested with Iodine to double check if the substance conta ...
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141 Titration Experiment Write
Grossmont, CHEMISTRY 141
Excerpt: ... Titration Experiment Write-up Lab Notebook Procedure reference the handout; be sure to include any changes. Data a clear record of your data collection. All volume measurements should have been recorded to two decimal places off of your buret. Lab book format signature, stamp, etc Informal Report Title page with name, date, experiment title, and section # Cut and paste the grading rubric at the base of this document on the title page Objective-What is the major goal(s) of this experiment? Be sure to be specific, but limit your objective to 3-4 sentences maximum. Results and calculation section Report your average gram molar mass with standard deviation and average melting point. Show your calculations. These may be typed or handwritten. Note any unusual or unexpected observations in the experiment. Discussion State the identity of your unknown acid . Discuss how you came to that conclusion using your average gram molar mass with standard deviation and average melting point range to justif ...
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USS4
University of Texas, CH 204
Excerpt: ... CH 204 Fall 2007 Unknown summary sheet for Experiment 4 "Acid-Base Titration" Name _ TA _ Date _ Unknown # _ Section # _ Identify your acid Molarity of your unknown acid ...
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USS4
University of Texas, CH 204
Excerpt: ... CH 204 Fall 2006 Unknown summary sheet for Experiment 4 "Acid-Base Titration" Name _ TA _ Date _ Unknown # _ Section # _ Identify your acid Molarity of your unknown acid ...
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Expt 04 USS
University of Texas, CH 204
Excerpt: ... CH 204 Fall 2005 Unknown summary sheet for Experiment 4 Acid-Base Titration Name _ TA _ Date _ Unknown # _ Section # _ Identify your acid Molarity of your unknown acid ...
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USS4
University of Texas, CH 204
Excerpt: ... CH 204 Spring 2008 Unknown summary sheet for Experiment 4 Acid-Base Titration Name _ TA _ Date _ Drawer # _ Section # _ Identify your acid Molarity of your unknown acid (M) ...
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USS4
University of Texas, CH 204
Excerpt: ... CH 204 Fall 2008 Unknown summary sheet for Experiment 4 "Acid-Base Titration" Name _ TA _ Date _ Drawer # _ Section # _ Identify your acid Molarity of your unknown acid (M) ...
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Expt 04 USS
University of Texas, CH 204
Excerpt: ... CH 204 Spring 2006 Unknown summary sheet for Experiment 4 "Acid-Base Titration" Name _ TA _ Date _ Unknown # _ Section # _ Identify your acid Molarity of your unknown acid ...
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USS4
University of Texas, CH 204
Excerpt: ... CH 204 Spring 2007 Unknown summary sheet for Experiment 4 "Acid-Base Titration" Name _ TA _ Date _ Unknown # _ Section # _ Identify your acid Molarity of your unknown acid ...
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USS4
University of Texas, CH 204
Excerpt: ... CH 204 Spring 2009 Unknown summary sheet for Experiment 4 "Acid-Base Titration" Name _ TA _ Date _ Drawer # _ Section # _ Identify your acid Molarity of your unknown acid (M) ...
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Practice Midterm #1
UCLA, CHEM 20L
Excerpt: ... urve for this yellow dye? 4 Name a IV. Beers Law (Continued) You are given 0.20 L of a stock solution of 0.30 M 0.1% of FD&C Yellow No. 5 dye, commonly known as tatrazine. In the lab you find the following laboratory equipment with the known inherent error. Analytical balance 10.00-mL pipet 25.00-mL pipet 50.00-mL volumetric flask 100-mL volumetric flask 0.2 mg 0.02 mL 0.03 mL 0.04 mL 0.08 mL (D) (10 points) Outline a strategy to make a solution with the highest possible concentration after two dilutions. Use only a single pipet in each dilution but you may use the same pipet for a subsequent dilution. Describe the exact equipment you will use and the show all of your calculations for the concentrations. Calculate the inherent error for the final solution. 5 Name a V. Acid Base / Titration / Indicators In the laboratory you have been asked to determine the equivalent weight of an unknown acid . A stock solution of sodium hydroxide was prepared by transferring 0.6705 g to a 100- ...
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lab1ex
Colorado, CVEN 3454
Excerpt: ... Laboratory 1. Titration of an Unknown Acid CVEN 3454 Water Quality Spring 2002 by Clair Sawyer, Perry McCarty, and Gene Parkin Wednesday Early Morning Lab, 2 to 5 am Introduction The chemistry of organic and inorganic acids plays an important role in the buffering of natural waters against natural and anthropogenic inputs that affect the pH of natural water bodies. Many organisms in natural waters survive only in a narrow pH range; therefore, understanding of the response of water bodies to anthropogenic inputs is important. In this lab, we titrated an unknown acid with a strong base to determine its identity. The strong base concentration was standardized by titrating a biphthalate solution of known concentration. We also measured the pH of five samples from the Little James Creek watershed in northwestern Boulder County to assess the effect of acidic water flowing an abandoned mine near the confluence of the Little James Creek and Balarat Gulch (Figure 1). 4 3 5 Lit tle Ja me sC ree k at lar Ba lch Gu ...
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Lab5.WeakAcid.Titration.Proc
Allegheny, CHEM 112
Excerpt: ... in very high purity. In this experiment, you will first standardize a solution of NaOH by using it to titrate a primary standard, potassium hydrogen phthalate (KHC8H4O4, familiarly known as "KHP"). Then, you will use a pH meter to monitor the change in pH during a titration of the weak acid; this will allow you to determine the pKa of the acid. Finally, you will use the NaOH to titrate a known mass of an unknown acid ; this will allow you to compute the acid's molar mass. Comparison of the experimental results to the known molar masses and pKa's of possible weak acids will allow you to identify your unknown acid . Procedure Part A is to be done individually, A. Standardization of a sodium hydroxide solution. Place 0.4 - 0.6 g (be sure to record the precise mass) of dried potassium hydrogen phthalate (stored in the desiccator) in a clean 250 mL Erlenmeyer flask and dissolve the salt in about 75 mL of DI water. Fill a cleaned and conditioned buret with sodium hydroxide solution (provided). Titrate the potassium ...
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ch3
Hudson VCC, CHEM 31
Excerpt: ... toichiometry of Formulas and Equations Ch. 3 Page 11 of 14 Dilutions Example: How many mL conc. H2SO4 must be diluted to make 500.0 mL of 2.0 M H2SO4? G. Putting it all together: Chem 31D F07 The Stoichiometry of Formulas and Equations Ch. 3 Page 12 of 14 H. Titrations Quantitative reactions performed so as to reach stoichiometric equivalence at a determinable endpoint How is this done? Chem 31D F07 The Stoichiometry of Formulas and Equations Ch. 3 Page 13 of 14 Examples: 1. Standard determination of an NaOH solution. KHP + NaOH KPNa + H2O The mass of the primary standard is 0.8512 g, and it takes 42.15 mL of NaOH solution to reach the equivalence point. What is the concentration of NaOH? 2. Titration of an unknown acid sample 25.00 mL of an unknown acid sample was titrated with 31.75 mL of the above NaOH solution. What was the initial concentration of the acid solution? Chem 31C F06 The Stoichiometry of Formulas and Equations Ch. 3 Page 14 of 14 ...
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Determination of an unknown acid by PK
Marquette, CHEM 102
Excerpt: ... Determination of an Unknown Acid by its pKa April 1, 2008 Lab Section 2107 Course Number 4103 Simon Duri Amanda Quella Laura Boucher Purpose: To determine an unknown acid by its PK. Procedure: 1. Three different masses of the unknown: 0.105 g, 0.100 g, 0.100 g, and 0.104 g were titrated with standardized NaOH solution. 2. 0.097 grams of unknown were titrated with standardized NaOH solution with the pH measured after the addition of about 1.0-1.5 mL of NaOH. 3. The density of the unknown was determined by weighing a 1.00 mL volumetric flask with the stopper, a small portion of the unknown which was transferred to the flask, then filled with hexane, and the total mass was measured. 4. The melting point of the unknown was determined through the use of a capillary tube and a melting point mechanism. 5. The melting point of the unknown was also determined through mixing the unknown with some possible acids. The two substances were ground together and then the melting point was again determined. Data ...
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Ka
Ill. Chicago, CHEM 112
Excerpt: ... Chemistry 112/116 Additional Notes for Ka lab The lab for week 11 is the Determination of the Molar Mass and Ka of a Weak Acid. Students practice with a known weak acid and then repeat the procedures with an unknown. They will determine three quantities for the weak acid: molarity, molar mass, and the Ka. They will identify their unknown acid . 1) The molarity is found easily by titration with NaOH solution of known molarity. 2) The molar mass if found by dividing the grams of acid by the moles of acid. 3) The Ka is found in three ways: a) they can directly calculate it as they will have the molarity of the acid (from the titration) and the initial pH (which will give them the initial molarity of hydronium ion); [H O + ][A - ] Ka = 3 ; [A-] = [H3O+] = 10-pH [HA] b) pH = pKa at the half-equivalence point in the titration of a weak acid with a strong base. The procedure includes two ways to arrive at the half-equivalence point. 1) Do a full titration to the endpoint. Identify the total volume of NaOH needed to ...
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Midterm #2.2
UCLA, CHEM 20L
Excerpt: ... nge of undissociated conjugate of 0.1000 M reagents of acid and base (Explain below) base indicator color change SA-SB WA-SB WB-SA Bromocresol green Phenolphthalein Methyl red Methyl orange Give your reasoning for choice of titration. (b) Calculate the pH of a 1.85 x 10-2 M solution of Ba(OH)2. 2 5. A 10.00-mL sample of an unknown acid was titrated with 0.1015 M NaOH. The titration data is shown below along with the Excel plot of the first derivative ($pH/$V vs volume base) graph in the vicinity of the equivalence point. Vol NaOH 0.07 3.02 5.98 9.13 12.22 12.49 13.00 13.90 13.98 14.10 14.14 14.22 14.25 14.31 pH 2.59 4.03 4.46 4.82 5.29 5.39 5.53 5.92 5.99 6.09 6.14 6.21 6.28 6.37 Vol NaOH 14.36 14.40 14.45 14.49 14.55 14.60 14.64 14.69 14.74 14.81 14.92 15.00 15.49 pH 6.47 6.59 6.78 7.24 8.55 9.71 10.40 11.07 11.32 11.44 11.53 11.66 11.97 40.00 35.00 30.00 25.00 20.00 15.00 10.00 5.00 0.00 14.20 14.40 14.60 Volume of NaOH 14.80 15.00 (a) What is the equivalence point volume? (b) What is the concentrati ...
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Schedule W08
Michigan, CHEM 125
Excerpt: ... & Halides. 3. Analysis of redox reactions. 2/5 (200 sect) 2/7 (100 sect) 2/12 (200 sect) 2/14 (100sect)* and 69-97 196-202 55 2/14-15 2/19 Hourly I Tuesday, March 11 Optional Reviews: Sat., March 8, 11 am 1pm; Mon., March 10, 6-8pm Rooms TBA (and on web site) 2/21-2/22 3/4 6:15 - 7:45 pm Rooms TBA 1 Chemistry 125/126 Winter 2008 (page 2) Experiment # Topics 4 Acids, Bases and Salts 1. Structure and acid-base properties. 2. Conjugate acid-base pairs. 3. Neutralization and Indicators. 4. Quantitative Studies of Neutralization. 5. Identification of an unknown acid . Dates Pre-Lab Lecture 2/19 (200 sect)* Dates Laboratory Discussion* 2/21-2/22* 3/4 and Pre-lab Reading Lab Pages Points 98-126 183-188 203-206 55 2/21 (100 sect) and 3/4 (200 sect)* 3/6 (100 sect) *Note: No lectures 2/26 and 2/28 Spring break 3/6-3/7 3/11 No labs, 2/25-2/29 Spring break 3/13-3/14; 3/18 3/13-3/14 3/18 3/20-3/21 and 5 Lewis acids & bases: Complexation 3/11 (200 sect) 1. Cation acidity & the Periodic Table 3/13 (100 s ...
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