peer review

User Generated

ryxnnov

Science

Description

I want you to do a review for the two files. there is 7 things. each one should be 50 words. i want each one sprit from the others.

find for me a 5 mistakes from each file.

1- Introduction: Background

Background: A summary of a real-world example(s) and / or application(s) that affirm the importance / help introduce the chemistry of this lab.

Note: Do not use the examples in the laboratory manual. If included in your laboratory report, no credit will be given.

Describe why it may be necessary to identify unknown chemicals in day-to-day life with specific examples.

The example(s) and / or application(s) provided

2- Theory: Provide an overview of the key scientific concepts / theories that explain how the experiment works.

Concepts that can be included but are not limited to:

-Qualitative/Quantitative analysis

-Solubility

-Conductivity

-pH

-Flame test

-Gravimetric analysis

-Volumetric analysis

The overall goal of this section should be to help familiarize your readers (who may be non-scientists) with the topics you have introduced and the importance of your work.

3- Hypothesis: A hypothesis should logically express what the researcher thinks the overall outcome of the lab

should be.

Objectives: The goal to be achieved at the end of each part of the experiment and a summary on how those goals will be attained.

Hypothesis: From the physical properties of your unknown (texture, color, etc.), what chemical do you hypothesize your unknown to be. Remember to include your rationale for why you think your hypothesis is reasonable.


4- Methods: This section should contain all of the details recorded in your notebook on how the experiments were carried out.

This includes numerical details such as mass, volume, temperature, reaction time, etc.

Note: Each experiment should have its own appropriate subheading.

The two main tasks of this section are to:

Describe the exact laboratory apparatus and laboratory procedure a researcher utilized to collected empirical data.


5- Results: This section should contain all of the empirical data you obtained or calculated from the experiment you performed.

The data should be displayed appropriately, i.e. tabulated, graphed, etc. to make it easy for the reader to refer back

to it in the corresponding discussion section.

Therefore, each table, graph, etc. should be numbered and titled appropriately.

Use a table to organize the empirical data you collected per trial for all the tests carried out.


6- A goal of this section is to include a restate the experiment’s hypothesis and objectives.

In addition, a summary should be provided on whether or not your hypothesis was affirmed or denied based

on your empirical data.

Finally, briefly outline any major sources of error that could have given unexpected results.

What was the purpose of the experiment?

Did you learn anything new when you executed the experiment?


7- Any idea, concept, application etc., that did not originate from you personally must be cited.

Please utilize ACS (American Chemical Society) format and have both an in-text citation, as well as the full citation under the references heading.

As a reminder, directly quoting an external source is unacceptable.

You are required to paraphrase, in your own words, all cited information that appears in your laboratory report.

Use ACS (American Chemical Society) citation format.

All in-text citations should be cited with a superscript number, and should match the appropriate cited external reference in the references section.

Superscript numbers are issued based on the order they appear in the document.

They are not based on the alphabetical last name of the author of the external source you're citing

Unformatted Attachment Preview

Template for Lab report Project 1: Identification of Inorganic Salts Antonio Morales CHS-2440L I. Introduction 1 page: - where you describe why you did the experiment - describe the theory about the different test - describe what you did to prove the theory The ability to determine an unknown sample of a compound is incredible because it opens a world of possibilities. Whether if it is identifying something form other space or an athlete doping himself, these abilities allows us to find the unknown. In order to find the solutions, one has to do several tests both qualitative and quantitative. This project is based on determining the identity of a compound based on unique properties that define that compound. By performing quantitative and qualitative analysis, like a gravimetric analysis for the former and flame test for the later. Also, we observed how this known salt reacted with different compounds. With the result obtained and some calculations made we can assume the compound because we are measuring it properties both physical and chemical. II. Procedures and methods A. Preparation of a 1wt% solution for Unknown and “salt used” B. pH Testing C. Solubility test D. Conductivity Testing E. Flame Test F. Precipitation test with Silver Nitrate and Barium Chloride G. Preparation of solutions for gravimetric analysis H. Gravimetric analysis Table 1: Safety information Chemical Potential Danger Precautions Barium Nitrate Potential Acute Health Effects: Extremely hazardous in case of ingestion. Very hazardous in case of skin contact (irritant), of eye contact (irritant), of inhalation. Prolonged exposure may result in skin burns and ulcerations. Over-exposure by inhalation may cause respiratory irritation. Inflammation of the eye is characterized by redness, watering, and itching. Skin inflammation is characterized by itching, scaling, reddening, or, occasionally, blistering. Eye Contact: Check for and remove any contact lenses. In case of contact, immediately flush eyes with plenty of water for at least 15 minutes. Cold water may be used. Get medical attention immediately. Potential Chronic Health Effects: Extremely hazardous in case of ingestion. Very hazardous in case of skin contact (irritant), of eye contact (irritant), Skin Contact: In case of contact, immediately flush skin with plenty of water for at least 15 minutes while removing contaminated clothing and shoes. Cover the irritated skin with an emollient. Cold water may be used. Wash clothing before reuse. Thoroughly clean shoes before reuse. Get medical attention immediately. Serious Skin Contact: Wash with a disinfectant soap and of inhalation. CARCINOGENIC EFFECTS: Not available. MUTAGENIC EFFECTS: Not available. TERATOGENIC EFFECTS: Not available. DEVELOPMENTAL TOXICITY: Not available. The substance is toxic to kidneys, lungs, the nervous system. Repeated or prolonged exposure to the substance can produce target organs damage. Repeated or prolonged inhalation of dust may lead to chronic respiratory irritation. Calcium Nitrate Potential Acute Health Effects: Hazardous in case of skin contact (irritant), of eye contact (irritant), of ingestion, of inhalation. Slightly hazardous in case of skin contact (permeator). Prolonged exposure may result in skin burns and ulcerations. Over-exposure by inhalation may cause respiratory irritation. Potential Chronic Health Effects: CARCINOGENIC EFFECTS: Not available. MUTAGENIC EFFECTS: Not available. TERATOGENIC EFFECTS: Not available. DEVELOPMENTAL TOXICITY: Not available. The substance is toxic to lungs, mucous membranes. Repeated or prolonged exposure to the substance can produce target organs damage. cover the contaminated skin with an anti-bacterial cream. Seek immediate medical attention. Inhalation: If inhaled, remove to fresh air. If not breathing, give artificial respiration. If breathing is difficult, give oxygen. Get medical attention. Serious Inhalation: Evacuate the victim to a safe area as soon as possible. Loosen tight clothing such as a collar, tie, belt or waistband. If breathing is difficult, administer oxygen. If the victim is not breathing, perform mouth-tomouth resuscitation. Seek medical attention. Ingestion: Do NOT induce vomiting unless directed to do so by medical personnel. Never give anything by mouth to an unconscious person. If large quantities of this material are swallowed, call a physician immediately. Loosen tight clothing such as a collar, tie, belt or waistband. Eye Contact: Check for and remove any contact lenses. Immediately flush eyes with running water for at least 15 minutes, keeping eyelids open. Cold water may be used. Do not use an eye ointment. Seek medical attention. Skin Contact: After contact with skin, wash immediately with plenty of water. Gently and thoroughly wash the contaminated skin with running water and non-abrasive soap. Be particularly careful to clean folds, crevices, creases and groin. Cold water may be used. Cover the irritated skin with an emollient. If irritation persists, seek medical attention. Serious Skin Contact: Wash with a disinfectant soap and cover the contaminated skin with an anti-bacterial cream. Seek medical attention. Inhalation: Allow the victim to rest in a well ventilated area. Seek immediate medical attention. Serious Inhalation: Evacuate the victim to a safe area as soon as possible. Loosen tight clothing such as a collar, tie, belt or waistband. If breathing is difficult, administer oxygen. If the victim is not breathing, perform mouth-tomouth resuscitation. Seek medical attention. Hydrochloric Acid Potential Acute Health Effects: Very hazardous in case of skin contact (corrosive, irritant, permeator), of eye contact (irritant, corrosive), of ingestion, . Slightly hazardous in case of inhalation (lung sensitizer). Noncorrosive for lungs. Liquid or spray mist may produce tissue damage particularly on mucous membranes of eyes, mouth and respiratory tract. Skin contact may produce burns. Inhalation of the spray mist may produce severe irritation of respiratory tract, characterized by coughing, choking, or shortness of breath. Severe over-exposure can result in death. Inflammation of the eye is characterized by redness, watering, and itching. Skin inflammation is characterized by itching, scaling, reddening, or, occasionally, blistering. Potential Chronic Health Effects: Slightly hazardous in case of skin contact (sensitizer). CARCINOGENIC EFFECTS: Classified 3 (Not classifiable for human.) by IARC [Hydrochloric acid]. MUTAGENIC EFFECTS: Ingestion: Do not induce vomiting. Loosen tight clothing such as a collar, tie, belt or waistband. If the victim is not breathing, perform mouth-tomouth resuscitation. Seek immediate medical attention. Eye Contact: Check for and remove any contact lenses. In case of contact, immediately flush eyes with plenty of water for at least 15 minutes. Cold water may be used. Get medical attention immediately. Skin Contact: In case of contact, immediately flush skin with plenty of water for at least 15 minutes while removing contaminated clothing and shoes. Cover the irritated skin with an emollient. Cold water may be used.Wash clothing before reuse. Thoroughly clean shoes before reuse. Get medical attention immediately. Serious Skin Contact: Wash with a disinfectant soap and cover the contaminated skin with an anti-bacterial cream. Seek immediate medical attention. Inhalation: If inhaled, remove to fresh air. If not breathing, give artificial respiration. If breathing is difficult, give oxygen. Get medical attention immediately. Not available. TERATOGENIC EFFECTS: Not available. DEVELOPMENTAL TOXICITY: Not available. The substance may be toxic to kidneys, liver, mucous membranes, upper respiratory tract, skin, eyes, Circulatory System, teeth. Repeated or prolonged exposure to the substance can produce target organs damage. Repeated or prolonged contact with spray mist may produce chronic eye irritation and severe skin irritation. Repeated or prolonged exposure to spray mist may produce respiratory tract irritation leading to frequent attacks of bronchial infection. Repeated exposure to a highly toxic material may produce general deterioration of health by an accumulation in one or many human organs. Acetone Potential Acute Health Effects: Hazardous in case of skin contact (irritant), of eye contact (irritant), of ingestion, of inhalation. Slightly hazardous in case of skin contact (permeator). Potential Chronic Health Effects: CARCINOGENIC EFFECTS: A4 (Not classifiable for human or animal.) by ACGIH. MUTAGENIC EFFECTS: Not available. TERATOGENIC EFFECTS: Not available. DEVELOPMENTAL TOXICITY: Classified Reproductive system/toxin/female, Reproductive system/toxin/male [SUSPECTED]. The substance is toxic to central nervous system (CNS). The substance may be toxic to kidneys, the reproductive system, liver, skin. Repeated or prolonged exposure to the substance can produce target organs damage. Serious Inhalation: Evacuate the victim to a safe area as soon as possible. Loosen tight clothing such as a collar, tie, belt or waistband. If breathing is difficult, administer oxygen. If the victim is not breathing, perform mouth-tomouth resuscitation. WARNING: It may be hazardous to the person providing aid to give mouth-to-mouth resuscitation when the inhaled material is toxic, infectious or corrosive. Seek immediate medical attention. Ingestion: If swallowed, do not induce vomiting unless directed to do so by medical personnel. Never give anything by mouth to an unconscious person. Loosen tight clothing such as a collar, tie, belt or waistband. Get medical attention immediately. Eye Contact: Check for and remove any contact lenses. Immediately flush eyes with running water for at least 15 minutes, keeping eyelids open. Cold water may be used. Get medical attention. Skin Contact: In case of contact, immediately flush skin with plenty of water. Cover the irritated skin with an emollient. Remove contaminated clothing and shoes. Cold water may be used.Wash clothing before reuse. Thoroughly clean shoes before reuse. Get medical attention. Serious Skin Contact: Wash with a disinfectant soap and cover the contaminated skin with an anti-bacterial cream. Seek medical attention. Inhalation: If inhaled, remove to fresh air. If not breathing, give artificial respiration. If breathing is difficult, give oxygen. Get medical attention if symptoms appear. Serious Inhalation: Evacuate the victim to a safe area as soon as possible. Loosen tight clothing such as a collar, tie, belt or waistband. If breathing is difficult, administer oxygen. If the victim is not breathing, perform mouth-tomouth resuscitation. Seek medical attention. Ethanol Potential Acute Health Effects: Hazardous in case of skin contact (irritant), of eye contact (irritant), of inhalation. Slightly hazardous in case of skin contact (permeator), of ingestion. Potential Chronic Health Effects: Slightly hazardous in case of skin contact (sensitizer). CARCINOGENIC EFFECTS: A4 (Not classifiable for human or animal.) by ACGIH. MUTAGENIC EFFECTS: Mutagenic for mammalian somatic cells. Mutagenic for bacteria and/or yeast. TERATOGENIC EFFECTS: Classified PROVEN for human. DEVELOPMENTAL TOXICITY: Classified Development toxin [PROVEN]. Classified Reproductive system/toxin/female, Reproductive system/toxin/male [POSSIBLE]. The substance is toxic to blood, the reproductive system, liver, upper respiratory tract, skin, central nervous system (CNS). Repeated or prolonged exposure to the substance can produce target organs damage. Ingestion: Do NOT induce vomiting unless directed to do so by medical personnel. Never give anything by mouth to an unconscious person. Loosen tight clothing such as a collar, tie, belt or waistband. Get medical attention if symptoms appear. Eye Contact: Check for and remove any contact lenses. Immediately flush eyes with running water for at least 15 minutes, keeping eyelids open. Cold water may be used. Get medical attention. Skin Contact: In case of contact, immediately flush skin with plenty of water. Cover the irritated skin with an emollient. Remove contaminated clothing and shoes. Cold water may be used.Wash clothing before reuse. Thoroughly clean shoes before reuse. Get medical attention. Serious Skin Contact: Wash with a disinfectant soap and cover the contaminated skin with an anti-bacterial cream. Seek medical attention. Inhalation: If inhaled, remove to fresh air. If not breathing, give artificial respiration. If breathing is difficult, give oxygen. Get medical attention if symptoms appear. Serious Inhalation: Evacuate the victim to a safe area as soon as possible. Loosen tight clothing such as a collar, tie, belt or waistband. If breathing is difficult, administer oxygen. If the victim is not breathing, perform mouth-to- mouth resuscitation. Seek medical attention. Silver Nitrate Potential Acute Health Effects: Very hazardous in case of skin contact (irritant), of ingestion. Hazardous in case of skin contact (permeator), of eye contact (irritant), of inhalation. Slightly hazardous in case of skin contact (corrosive). The amount of tissue damage depends on length of contact. Eye contact can result in corneal damage or blindness. Skin contact can produce inflammation and blistering. Inhalation of dust will produce irritation to gastro-intestinal or respiratory tract, characterized by burning, sneezing and coughing. Severe over-exposure can produce lung damage, choking, unconsciousness or death. Prolonged exposure may result in skin burns and ulcerations. Overexposure by inhalation may cause respiratory irritation. Potential Chronic Health Effects: CARCINOGENIC EFFECTS: Not available. MUTAGENIC EFFECTS: Not available. TERATOGENIC EFFECTS: Not available. DEVELOPMENTAL TOXICITY: Not available. The substance is toxic to lungs. The substance may be toxic to mucous membranes, skin, eyes. Repeated or prolonged exposure to the substance can produce target organs damage. Repeated exposure of the eyes to a low level of dust can produce eye irritation. Repeated skin exposure can produce local skin destruction, or dermatitis. Ingestion: Do NOT induce vomiting unless directed to do so by medical personnel. Never give anything by mouth to an unconscious person. Loosen tight clothing such as a collar, tie, belt or waistband. Get medical attention if symptoms appear. Eye Contact: Check for and remove any contact lenses. In case of contact, immediately flush eyes with plenty of water for at least 15 minutes. Cold water may be used. Get medical attention. Skin Contact: In case of contact, immediately flush skin with plenty of water for at least 15 minutes while removing contaminated clothing and shoes. Cover the irritated skin with an emollient. Cold water may be used.Wash clothing before reuse. Thoroughly clean shoes before reuse. Get medical attention immediately. Serious Skin Contact: Wash with a disinfectant soap and cover the contaminated skin with an anti-bacterial cream. Seek immediate medical attention. Inhalation: If inhaled, remove to fresh air. If not breathing, give artificial respiration. If breathing is difficult, give oxygen. Get medical attention. Serious Inhalation: Evacuate the victim to a safe area as soon as possible. Loosen tight clothing such as a collar, tie, belt or waistband. If breathing is difficult, administer oxygen. If the victim is not breathing, perform mouth-tomouth resuscitation. WARNING: It may be hazardous to the person providing aid to give mouth-to-mouth resuscitation when the inhaled material is Repeated inhalation of dust can produce varying degree of respiratory irritation or lung damage. Sodium Carbonate Potential Acute Health Effects: Hazardous in case of skin contact (irritant), of eye contact (irritant), of ingestion, of inhalation (lung irritant). Potential Chronic Health Effects: Slightly hazardous in case of skin contact (sensitizer). CARCINOGENIC EFFECTS: Not available. MUTAGENIC EFFECTS: Not available. TERATOGENIC EFFECTS: Not available. DEVELOPMENTAL TOXICITY: Not available. The substance may be toxic to upper respiratory tract, skin, eyes. Repeated or prolonged exposure to the substance can produce target organs damage. toxic, infectious or corrosive. Seek immediate medical attention. Ingestion: Do NOT induce vomiting unless directed to do so by medical personnel. Never give anything by mouth to an unconscious person. If large quantities of this material are swallowed, call a physician immediately. Loosen tight clothing such as a collar, tie, belt or waistband. Eye Contact: Check for and remove any contact lenses. In case of contact, immediately flush eyes with plenty of water for at least 15 minutes. Cold water may be used. Get medical attention. Skin Contact: In case of contact, immediately flush skin with plenty of water. Cover the irritated skin with an emollient. Remove contaminated clothing and shoes. Cold water may be used.Wash clothing before reuse. Thoroughly clean shoes before reuse. Get medical attention. Serious Skin Contact: Wash with a disinfectant soap and cover the contaminated skin with an anti-bacterial cream. Seek immediate medical attention. Inhalation: If inhaled, remove to fresh air. If not breathing, give artificial respiration. If breathing is difficult, give oxygen. Get medical attention. Sodium Hydroxide Potential Acute Health Effects: Very hazardous in case of skin contact (corrosive, irritant, Ingestion: Do NOT induce vomiting unless directed to do so by medical personnel. Never give anything by mouth to an unconscious person. Loosen tight clothing such as a collar, tie, belt or waistband. Get medical attention if symptoms appear. Eye Contact: Check for and remove any contact lenses. In case of contact, immediately permeator), of eye contact (irritant, corrosive), of ingestion, of inhalation. The amount of tissue damage depends on length of contact. Eye contact can result in corneal damage or blindness. Skin contact can produce inflammation and blistering. Inhalation of dust will produce irritation to gastrointestinal or respiratory tract, characterized by burning, sneezing and coughing. Severe over-exposure can produce lung damage, choking, unconsciousness or death. Inflammation of the eye is characterized by redness, watering, and itching. Skin inflammation is characterized by itching, scaling, reddening, or, occasionally, blistering. Potential Chronic Health Effects: CARCINOGENIC EFFECTS: Not available. MUTAGENIC EFFECTS: Mutagenic for mammalian somatic cells. TERATOGENIC EFFECTS: Not available. DEVELOPMENTAL TOXICITY: Not available. The substance may be toxic to mucous membranes, upper respiratory tract, skin, eyes. Repeated or prolonged exposure to the substance can produce target organs damage. Repeated exposure of the eyes to a low level of dust can produce eye irritation. Repeated skin exposure can produce local skin destruction, or dermatitis. Repeated inhalation of dust can produce varying degree of respiratory irritation or lung damage. flush eyes with plenty of water for at least 15 minutes. Cold water may be used. Get medical attention immediately. Skin Contact: In case of contact, immediately flush skin with plenty of water for at least 15 minutes while removing contaminated clothing and shoes. Cover the irritated skin with an emollient. Cold water may be used.Wash clothing before reuse. Thoroughly clean shoes before reuse. Get medical attention immediately. Serious Skin Contact: Wash with a disinfectant soap and cover the contaminated skin with an anti-bacterial cream. Seek medical attention. Inhalation: If inhaled, remove to fresh air. If not breathing, give artificial respiration. If breathing is difficult, give oxygen. Get medical attention immediately. Serious Inhalation: Evacuate the victim to a safe area as soon as possible. Loosen tight clothing such as a collar, tie, belt or waistband. If breathing is difficult, administer oxygen. If the victim is not breathing, perform mouth-tomouth resuscitation. WARNING: It may be hazardous to the person providing aid to give mouth-to-mouth resuscitation when the inhaled material is toxic, infectious or corrosive. Seek immediate medical attention. Ingestion: Do NOT induce vomiting unless directed to do so by medical personnel. Never give anything by mouth to an unconscious person. If large quantities of this material are swallowed, call a physician immediately. Loosen tight clothing such as a collar, tie, belt or waistband. III. Results Table 2: Results from pH test on a 1wt% solution Trial Unknown sample Calcium Nitrate 1 7.1 7.3 2 6.9 7.2 3 7.0 7.1 average 7.0 7.2 Table 3: Results observable properties Trial Unknown sample Calcium Nitrate Color of the sample White White Color of the flame Red Red Table 4: Results from solubility test on a solid sample Trial Unknown sample Calcium Nitrate Acetone Soluble Soluble Ethanol Partly soluble Partly soluble 3M HCl Soluble Soluble 3M NaOH Not Soluble Not Soluble Water Soluble Soluble Table 5: Results from conductivity test on a 1wt% solution Trial Unknown sample Calcium Nitrate 1 7.45 7.68 2 7.49 7.64 3 7.40 7.97 average 7.46 7.76 Table 6: Results from precipitation test on a 1wt% solution Trial 1 Unknown sample Unknown sample Calcium Calcium Nitrate with silver nitrate with barium chloride Nitrate with with barium silver nitrate chloride No Precipitate No Precipitate No Precipitate No Precipitate 2 No Precipitate No Precipitate No Precipitate No Precipitate 3 No Precipitate No Precipitate No Precipitate No Precipitate Table 7: Results from gravimetric analysis Trial Unknown sample Percent yield Calcium Nitrate Percent yield 1 0.13g 46% 0.01 g 3.57% 2 0.01g 3.57% 0.01g 3.57% 3 0.09g 32.14% 0.2g 71.43% average 0.10g 27.24 0.07g 26.31 Calculations a. Preparation of a 1wt% solution 10.52 gr of unknown in 100ml of water 10.53 gr of Calcium Nitrate in 100 ml of water b. Average of 3 trials for “pick one test” c. Theoretical yield from gravimetric analysis 𝐶𝑎𝑁𝑂3 + 𝑁𝑎2 𝐶𝑂3 = 𝐶𝑎𝐶𝑂3 + 𝑁𝑎𝑁𝑂3 Filter paper= 0.33 grams Filter paper with precipitate= 0.43 grams Precipitate weight= 0.1 grams .3𝑔𝑟 𝐶𝑎𝑁𝑂 1 𝑚𝑜𝑙𝑒 Theoretical 1 𝑚𝑜𝑙𝑒 3 𝑥 105.98 𝑔𝑟 𝐶𝑎𝑁𝑂 𝑥 164.088𝑔𝑟 𝐶𝑎𝐶𝑂3= .28 gr CaCO3 3 Experimental 0.1g CaN03 d. Percent yield [(Actual)/(theoretical)]x100 0.01g CaN03/( .28CaN03) = 46% IV. Discussion Discuss all the test and from each one show what allows you to identify the unknown. (second draft) V. Conclusion Our results were pretty accurate and on point with the actual compound. Our unknown had the same results as the Calcium Nitrate for all the solubility, flame, precipitate, conductivity, pH, and gravimetric analysis test. Since all the test, except the gravitational analysis were accurate, we could correctly assume that the unknown compound was Calcium Nitrate. The gravitational analysis had a low percent yield because we made two mistakes. The first was a spill when handling the liquids used. The second experimental error was that when we transferred the solution with precipitate into the paper sheet we left some in the beaker because we did not properly empty the solution into the paper by adding more water to get the precipitate of the beaker. Besides this test, all the other tests were handed carefully for maxium accuracy and we had good results. The easiest test to identify the compound was the Flame test and the physical property test. We could immediately tell with the color, what substance we were dealing with. VI. Research connection (second draft) Find a research paper that you find interesting What were they trying to do? What was the main experiment? What did they find? References ACS style 1 References in order of appearances, and use the number to cite them in the text 2 References in order of appearances, and use the number to cite them in the text 3 References in order of appearances, and use the number to cite them in the text 4 References in order of appearances, and use the number to cite them in the text Lab 1 Report Bucci Douglas General Chemistry for Engineers Lab I. Introduction The intent of the lab was to find out what salt our group was given by using multiple different methods and experiments. We used several tests including, pH testing, a solubility test, a conductivity test, a flame test, a precipitation test with Silver Nitrate and Barium Chloride, and gravimetric analysis. Using the pH test allowed us to learn if the salt was acidic or basic. The flame test allowed us to see the color the flame would be when burned and then compare it to other flames which let us narrow down our choices. The solubility test allowed us to find what liquids the salt was soluble in and compare it with other salts. The conductivity test also allowed us to determine the conductivity and compare it with other known samples. The precipitate test, allowed us to see how the salt precipitated and compare that with other samples. For the gravimetric analysis, we were able to find the yield of the mass of the salt used and find the mass of the salt. All these theories were proved through multiple trials, where the average values from some of the test were used to find the result. With all the results obtained from these experiments, we were able to compare our results with the same experiments on other salts of known values. We narrowed down the possible salts we could have been given, so that we were left with one. We then repeated all the experiments with the salt we thought we had so that we could compare the results to see if they line up, and to confirm that we had the correct salt. II. Procedures and methods A. Preparation of a 1wt% solution for Unknown and “salt used” B. pH Testing C. Solubility test D. Conductivity Testing E. Flame Test F. Precipitation test with Silver Nitrate and Barium Chloride G. Preparation of solutions for gravimetric analysis H. Gravimetric analysis Table 1: Safety information Chemical Potential Danger Precautions Ethanol Flammable Wear gloves, lab coat, and goggles Acetone Flammable, Irritant, Poisonous Wear gloves, lab coat, and goggles HCl Corrosive, Can damage skin Wear gloves, lab coat, and goggles NaOH Corrosive, Can damage skin Wear gloves, lab coat, and goggles Ca(NO3)2 Skin and Eye Irritant Wear gloves, lab coat, and goggles Na2CO3 Skin and Eye Irritant Wear gloves, lab coat, and goggles 2NaNO3 Skin and Eye Irritant Wear gloves, lab coat, and goggles CaCO3 Skin and Eye Irritant Wear gloves, lab coat, and goggles III. Results Table 2: Results from pH test on a 1wt% solution Trial Unknown sample Calcium Nitrate 1 7.3 pH 7.3 pH 2 7.1 pH 7.2 pH 3 7.3 pH 7.1 pH average 7.23 pH 7.2 pH Table 3: Results observable properties Trial Unknown sample “salt used” Color of the sample White Crystal White Crystal Color of the flame Red Red Table 4: Results from solubility test on a solid sample Trial Unknown sample Calcium Nitrate Acetone Insoluble Insoluble Ethanol Insoluble Insoluble 3M HCl Insoluble Insoluble 3M NaOH Soluble Soluble Water Soluble Soluble Table 5: Results from conductivity test on a 1wt% solution Trial Unknown sample Calcium Nitrate 1 4.41 5.64 2 5.06 8.67 3 9.42 12.09 average 6.29 8.80 4.91 Conductivity of Calcium Nitrate Table 6: Results from precipitation test on a 1wt% solution Trial 1 Unknown sample Unknown sample “salt used” with “salt used” with with silver nitrate with barium chloride silver nitrate barium chloride Precipitates Doesn’t Precipitate Precipitates Doesn’t Precipitate 2 Precipitates Doesn’t Precipitate Precipitates Doesn’t Precipitate 3 Precipitates Doesn’t Precipitate Precipitates Doesn’t Precipitate Table 7: Results from gravimetric analysis Trial Unknown sample Percent yield Calcium Nitrate Percent yield 1 0.32g 11.6% 0.33g 6.6% 2 0.34g 10.8% 0.32g 11.6% 3 0.32 13.3% 0.31g 9.9% average 0.33g 11.9% 0.32g 9.4% Calculations a. Preparation of a 1wt% solution a. 1g / 100 mL b. Average of 3 trials for “pick one test” a. (T1+T2+T3) / 3 c. Theoretical yield from gravimetric analysis a. 250 mL / 2.5g = 30 mL / 0.3g is the amount of Na2CO3 in the solution d. Percent yield a. Percent Yield = (Actual Yield / Theoretical Yield) x 100% IV. Discussion Discuss all the test and from each one show what allows you identify the unknown. Finding the pH value for the salt allowed us to know what its range would be, if it was acidic or basic. The flame test let us match the color of our salt when burned with other salts to narrow down the list of salts. The solubility test helped us to find out which liquids our salt was soluble in. The conductivity test let us determine the conductivity and compare it with other known salts. The precipitate test, allowed us to see how the salt precipitated. For the gravimetric analysis, we were able to find the yield of the mass of the salt used and find the mass of the salt. V. Conclusion What was your unknown salt a what was the most valuable test to identify it. Our unknown salt was Calcium Nitrate. The most useful test we used to identify our salt was the flame test because it gave us a clear visual representation. VI. Research connection This research, scientists were trying to increase the salt tolerance of crops. The scientist screened large numbers of crops for genotypes of salt tolerance to find salt tolerant germplasm. They found that the trait of sodium exclusion has a high heritability which will enable them to screen these crops faster and more precisely. References Rana Munns, Shazia Husain, Anna Rita Rivelli, Richard A. James, A. G. Tony Condon, Megan P. Lindsay, Evans S. Lagudah, Daniel P. Schachtman, Ray A. Hare, Avenues for increasing salt tolerance of crops, and the role of physiologically based selection traits [Online], https://link.springer.com/chapter/10.1007/978-94-017-2789-1_7 (Accessed February 25, 2018)
User generated content is uploaded by users for the purposes of learning and should be used following Studypool's honor code & terms of service.

This question has not been answered.

Create a free account to get help with this and any other question!

Related Tags