Chem lab Essay

Submitted By nicacameron
Words: 898
Pages: 4
Open Document
Solution Stoichiometry Experiment Group submitted: Partner(s):

Purpose: For this experiment, my partner and I will complete three different parts. For part I, we will determine which indicator we will use for part II and III. We will test three indicators, Boomcreiol, Methyl, and 1% Phenolphthalein. For part II you will take the indicator you have chosen and use titrations with NaOH to see how much it takes to neutralize HCl. For part III you will do the same thing but to see how much it takes to neutralize H₂SO₄.

Procedures: My partner, Marisa, and I will work together to complete this experiment. We will first determine which indicator we will use for the titrations in part II and III. Once we determine that, we use it with the sets of titrations with NaOH. Both Marisa and I will equally do work for both parts I, II, and III.

Part I - Acid-Base Titrations with Chemical Indicators
We obtained a 24 chem well-plate, 40 mL of HCl, and 100 mL of NaOH.
We cleaned out a buret with the base, NaOH.
We then obtained three different indicators: Boomcreiol green, Methyl orange, and 1% Phenolphthalein.
Using the well-plate we sorted the indicators into 3 rows.
To one well of each row of indicator, we added 5 drops of HCl, 5 drops of distilled water, and 5 drops of NaOH.
We determined which indicator we would use for part II and III: 1% Phenolphthalein.

Part II - Titration of unknown HCl with standardized NaOH using a Chemical Indicator
We took a 10.00 mL pipette and cleaned it with HCl.
We filled 10.00 mL of HCl and put it in the 125 mL flask, plus two drops of indicator.
We preformed 3 different titrations to determine how long it would take to neutralize the HCl.

Part III - Titration of unknown H₂SO₄ with standardized NaOH using a Chemical Indicator
We took a 10.00 mL pipette and cleaned it with H₂SO₄.
We filled 10.00 mL of H₂SO₄ and put it in the 125 mL flask, plus two drops of indicator.
We preformed 3 different titrations to determine how long it would take to neutralize the H₂SO₄.
Data and Results: The data tables I will display are also found in my carbonless copy lab notebook.

Results for Part I

Table 1. Selection of Chemical Indicators:
Row
Column 1
(HCl 5 drops)
Column 2
(Water 5 drops)
Column 3
(NaOH 5 drops)
Boomcreiol green
Yellow
Blue
Blue
Methyl orange
Red
Yellow
Yellow
1% Phenolphthalein
Clear
Clear
Pink

This best indicator to use from Table 1 would be the 1% Phenolphthalein. We’re using NaOH with both of our titration samples, so we would like the NaOH to be the different color from the rest.

Results for Part I

Concentration of NaOH: 0.1236 M

Table 2. Titrations for Part II:
Titration
Initial Vol. NaOH (mL)
Final Vol. NaOH (mL)
Vol. NaOH used (mL)
Concentration of HCl (M)
1
0.01
12.00
11.99
0.1482
2
12.00
23.80
11.80
0.1458
3
23.80
35.06
11.98
0.1481

Example calculations of moles of NaOH: moles of NaOH = (volume NaOH in L)*(M of NaOH) = (0.01199 L)*(0.1236) = 1.48 x 10⁻² mol NaOH

Example calculation of moles of HCl: moles of HCl = moles NaOH used = 1.48 x 10 ⁻² moles HCl

Example calculation of concentration of HCl: concentration of HCl = (moles HCl) / (volume HCl in L) = (1.48 x 10 ⁻² moles) / (0.01 L HCl) = 0.1482 M HCl

Average concentration of HCl with standard deviation: Avgerage concentration of HCl = (0.1482 M) + (0.1458 M) + (0.1481 M) / 3 = 0.1474 M HCl Standard deviation of HCl: 0.1482 M - 0.1474 M = (0.0008 M)² = 0.00000064 M 0.1458 M - 0.1474 M = (-0.0016 M)² = 0.00000256 M 0.1481 M - 0.1474 M = (0.0007 M)² = 0.00000049 M (0.00000064 M + 0.00000256 M + 0.00000049 M) = 0.00000369 M / 3 = 0.00000123 M = √(0.00000123 M) = σ = 1.11 x 10 ⁻³ M HCl Percent error of HCl: % error = (⎪Approx. Value - Exact Value⎪/⎪Exact Value⎪) x 100 % = (⎪0.1474 M - 0.1458⎪/⎪0.1458⎪) x 100 % = 1.10 %

Table 3. Titrations from part III:
Show More

Related Documents: Chem lab Essay

Chem 115 Lab

To begin Lab 8 of Chem 115, half a gram of copper wire was weighed out using an analytical scale and the exact mass was recorded. Next, the wire along with 4-5 mL of concentrated nitric acid was added to a 250 mL beaker in the hood. Once the reaction was completed and the wire was completely gone, 100 mL of distilled water was added to the beaker and observations were recorded. Next, 30 mL of 3.0 M sodioum hydroxide was added to the beaker and any observation of the reaction was recorded. Following…

Words 355 - Pages 2

Chem lab Essay

Part A: Sodium benzoate is used to preserve certain foods against bacteria, yeasts and molds and is used to prolong their shelf life. This compound, when ingested has the potential to mix with stomach acid and undergo a chemical reaction. In a lab, sodium benzoate can be combined with hydrochloric acid (HCl) to simulate the stomach environment. The purpose of this experiment is to determine when these two substances are combined, whether a new substance will be formed. It was predicted that…

Words 1152 - Pages 5

Chem Lab Essay

Keira Harris February 16, 2015 Step 1. Converting copper metal to copper nitrate. 1. Cut and weigh of copper wire until approximately 0.5g. 2. Record mass. 3. Place in a clean, dry 250 mL Erlenmeyer flask. 4. Measure 4-5 mL of concentrated nitric acid in a graduated cylinder. 5. In a fume hood, add the acid to the copper until it dissolves. 6. Swirl contents to dissolve copper. 7. If after 5 minutes it hasn't dissolved, gently warm on a hot plate or add 1-2 mL of nitric acid. 8. Swirl until…

Words 638 - Pages 3

chem lab Essay

I. Determining the Unknown Acid Sample Size Identification code of unknown weak acid #5 Concentration of NaOH solution, M .0609M Mass of weighing paper plus unknown acid,g .86 g Mass of weighing paper,g .8 g Final buret reading, mL 19.2 mL Initial buret reading, mL 13.5 mL III. Titrating the Unknown Acid Determination. 1 Determination 2 Mass of weighing paper plus unknown acid, g .922g .90g Mass of weighing paper, g .87…

Words 317 - Pages 2

Chem Lab Essay

II. Intro/Background Light is a continuous spectrum of frequencies and wavelengths. Depending on the size of the wavelength, its frequency will either be higher or lower. All light waves travel at the same speed. In this lab, you will be conducting an experiment to determine the effects that different color ultraviolet lights have on a glow star. III. Hypothesis We predict that the glow star will produce the color of the light that is shined on it. We predict this will occur because the waves…

Words 513 - Pages 3

chem lab Essay

Chem-101 Name_________________________ Date__________________________ THE MOLAR VOLUME OF HYDROGEN: THE REACTION OF MAGNESIUM WITH HYDROCHLORIC ACID PURPOSE: • The molar volume of hydrogen gas will be determined by experimentally measuring the volume of hydrogen evolved during the reaction of magnesium with hydrochloric acid. • The universal gas constant will be measured and class data will be combined for statistical data analysis. Mg(s) + 2HCl(aq) → MgCl2(aq) + H2(g) Laws and concepts…

Words 938 - Pages 4

Chem lab Essay

Lab report Introduction- An ester is “any class of often fragrant organic compounds that can be represented by the formula RCOOR′ and that are usually formed by the reaction between an acid and an alcohol with elimination of water.” We set out to create these esters on our own by combining acids like acetic acid, butyric acid, and benzoic acid with certain alcohols like ethanol, methanol, or pentanol. Each had a unique smell, which we would try to determine by smelling each. Objective- To…

Words 303 - Pages 2

Essay on Chem Pre Lab

Marriah Miranda CHEM 1411 February 4, 2015 Precision and Accuracy of Scientific Glassware Pre-Lab Report The objective of this experiment is to learn which scientific glassware should be used in various circumstances, how to measure volume and mass and how to record laboratory data and observations. Become familiar with significant figures, errors, precision and accuracy associated with the various tools and techniques. To Contain Glassware you will need two Erlenemeyer Flasks, one 125 mL to measure…

Words 972 - Pages 4

Chem Lab 1A Essay

Adam Meyer 18 Feb 2015 Experiment 1A The production and testing of Ca(OH)₂ with other substances Refer to pgs 1-8 for more laboratory information. . . Our Objectives . Observe the reaction between limewater and carbon dioxide; and to test the gaseous products of two chemical reactions for the presence of carbon dioxide. ( refer to the textbook pg 1 for further instruction.) . . Materials and Procedures . ( refer to the text book pg 1-2 for a full list of materials.) . . Observations and Data…

Words 1010 - Pages 5

Chem calormetry lab 2014 Essay

involves strong electrolytes are completely dissociated into ions in diluted solutions. In this lab both the base and acid were strong electrolytes. The heat of neutralization for all reactions involving strong electrolytes will be constant and the same amount of heat will be formed (Petrucci et al., 2011). Procedure The experimental procedure used for this experiment was outlined in the CHEM 120L lab manual, experiment #4. All steps were followed without deviation Observations Part A: Heat of dissolution…

Words 1974 - Pages 8