Lab 2

A common household chemical called naphthalene can sometimes be found in cabinets containing clothes and commonly referred to as "moth balls".

Consider a 0.10 M citric acid with Ka values given: H3C6H5O7 (aq) + H₂O(1) H₂C6H5O7 (aq) + H₂O) HC6H507² (aq) + H₂O(1) 1. Determine the predominating species at pH=5.00. A. H3C6H5O7 C. HC₂H5O7²- B. H₂C6H5O7 D. C₂H5O7³- Answer: H₂C6H5O7 (aq) + H3O+ (aq) HC6H507² (aq) + H30* (aq) C6H507³ (aq) + H3O+ (aq) 2. Determine the predominating species at pH=8.00. A. H3C6H5O7 C. HC6H5O7²- B. H₂C6H5O7 D. C6H5O7³- Answer: 4 K₂= 7.5 x 10-4 K₂ = 1.7 x 10-5 Ka = 4.0 x 10-7

Three alcohol bottles were mislabeled in the stockroom: 1-pentanol, 2-pentanol, and 3-pentanol. A clever student decided to using MS to determine the identity of the structures. Using the MS data, draw the structure of the compound found in each bottle. Bottle #1: Base peak with a m/z of 45 Bottle #2: Base peak with a m/z of 70 and two significant peaks with m/z of 42 and 31 Bottle #3: Base peak with a m/z of 59

what is the reading of this buret?

Complete the table.

What is wrong with the reaction of A

Q.No.3 What is chromatography?. Why chromatography is considered as an important tool for analysis of organic compounds.

(17360 Systane Part B CH3 CH3 CH3-CH₂-CH-CH-CH₂-OH Spell out the full name of the compound. Submit Request Answer Part C OH CH₂-CH3 P dy 44#1 BAKER -2221 51-19-145 ciation, Inc. OS WINE 19 25 OCT 2022 PM) Address Herbert Epstein 14773 Cumberland C DELRAY BEACH, F အင်းတင်း 46-135654 2 ^ [

Select one for each box

all 43% LTE 2:34 Question 4 of 8 Submit Construct the expression for Ka for the weak acid, NH,*. NH,*(aq) + H,0(10) = H,0*(aq) + NH;(aq) 1 Based on the definition of Ka, drag the tiles to construct the expression for the given acid. Ka %3D 5 RESET [H,O] [H,O*] [OH-] [NH,] [NH,] [NH,] 2[H,0O] 2[H,0*] 2[OH-] 2[NH,] 2[NH,] 2[NH,] [H,0]? [H,0*12 [OH-]? [NH,*)? [NH,]? [NH,-]? II

Name

There could be more than one correct answer

If Jotaro Kujo measured the amount of current that passes through a sample to measure the amount of analyte in the sample, what kind of method did he use?   Volumetric method   Spectroscopic method   Gravimetric method   Electroanalytical method

Which one is true?

Ethyl methyl ketone (1.jpg) Acetaldehyde (2.jpg) A recognition test will be applied to the organic substances given above. Which recognition test is applied to determine the organic substances correctly? Explain.

PLEASE Answer within 20-30 minutes. Thank you!

Sample #1 has an absorbance of 0.300. Sample #2 is the same substance and has an absorbance of 0.600 using the same equipment. What is the relative concentration of the second sample? Select one: a. The concentration of sample #2 is the square root of that of #1. b. The concentration of sample #2 is that of sample #1 squared. c. The concentration of sample #2 is half that of sample #1. d. The concentration of sample #2 is twice that of sample #1.

Please answer the rest. This is using up another one of my questions

The amino acid glycine (H₂N-CH2-COOH) has pK values of 2.35 and 9.78. Indicate the structure and net charge of the molecular species that predominate at pH 2, 7, and 10. Use the following structure format and add or remove protons and charges to provide your answer. Part 1 At pH 2: H₂N- H -OH ✔ Edit Drawing

If an analytical method relies on a measurable property of an analyte that can be correlated with the amount of the said analyte, what type of analytical method is it?   Oxidative methods   Instrumental methods   Blank Correction methods   Classical methods

Use the rule of 13 and mass spect data attached to propose the molecular formula. 151 represents both the M+ and base pwak

Suzy Baker What three areas are affected by an "irritant"? (refer to ACS Safety in the Academic Chemistry Laboratories Vol. 1)    [use the answer format= ans 1, ans 2, ans 3]

Need help with number 4. Theses are pre lab questions and not homework. Was rejected once and unsure why. Pre lab means before the actually lab we do (which that part is graded) Thanks

Dangerous Paint Stripper Jessica has a summer job working for the city parks program. She has been using a cleaner called “Graffiti Gone” to remove graffiti from the bathrooms. She has to take a lot of breaks, because the chemical makes her throat burn. It also makes her feel dizzy sometimes, especially when the bathrooms don’t have very many windows. On the label, she sees that the cleaner has methylene chloride in it. She feels like she’s managing to get the work done, but she is worried about feeling dizzy. She wants to find out more about this chemical, what harm it can cause, and whether there are safer ways to do this work. Questions for following story. 1. What went right in this situation? 2. What went wrong in this situation? 3. What steps should be taken in this workplace to make sure employees are better protected and prepared the next time?

3. What is the major obstacle that fractional distillation overcomes? 1 1° in422 male distillatio

8. Chemical Formula: C₂H₁7NOS 8 1H, broad 7 6 Final Answer 1H, broad 5 بللي بلد 4 PPM 3H s 3 2 9H s 1 there are 3 peaks between 4.00 and 4.30 ppm: a 1H t at 4.3 ppm two 1H t that both happen to be at 4.0 ppm, but are not the same 0

8. Chemical Formula: C9H17NO5 8 1H, broad 7 6 Final Answer 1H, broad -5 elle 4 PPM 3H s 3 2 9H s 1 there are 3 peaks between 4.00 and 4.30 ppm: a 1H t at 4.3 ppm two 1H t that both happen to be at 4.0 ppm, but are not the same 0

#40 & 42

Calculate the K₂ value for the following acids. (Enter your answer to three significant figures.) a) Formic acid (pK₂ = 3.75): 0.000178 b) Ethanol (pK₂ = 16.00): | Calculate pK₂ values for the following acids. (Enter your answer to three significant figures.) a. Nitric acid (K₂ = 20.0): b. Resorcinol (K₂ = 1.55x10-10):

Multiple Choice Each of the numbered items or incomplete statements is followed by answers or by completions of the statement. Select the one lettered answer or completion that is best in each case. Write your answer before each number. 42. Primary Standard reagent used in standardization of 0.1N sodium hydroxide a. Sulfamic acid C. sodium carbonate KHP b. sodium bicarbonate d. 43.An analyst who determines the strength, potency and percentage purity of a drug or pharmaceutical product is performing: a. Special method C. d. Pharmaceutical assaying Identification test b. Pharmacopoeial test 44.Chemical analysis which determines the amount or percentage content of a certain component in a sample: a. Qualitative C. d. Proximate Ultimate Quantitative ܩ b.

Dr. Waybell designs a study to investigate whether the dose of melatonin taken before bed impacts people's moods. Dr. Waybell rejects Ho and computes 7²=0.05. She has made a Type Il error. O Dr. Waybell retain reject Ho and computes n=0.005. She has made a Type Il error. O Dr. Waybell rejects Ho and computes 7=0.005. She has made a Type Il error. Dr. Waybell retain reject Ho and computes n=0.05. She has made a Type Il error.

Just tell me the correct answer

AP Question I/Q 1) A student has a mixture containing three different organic substances. The Lewis diagrams of the substances are below: H. H. H H H- Ö-H H-C H. H H H H. n-butanol ethyl chloride H. H. H. H- H H H. H. n-propylamine a. If the mixture is dabbed onto chromatography paper that was then placed into a polar solvent, rank the R, values for each component of the mixture from high to low after the solvent has saturated the paper. Justify your answer. b. If the mixture is poured into a chromatography column and then eluted with a very nonpolar substance, which component of the mixture would leave the column first, and why? 2) Select which of the following pieces of laboratory experiment could be used when measuring out 20.00 mL CoCl;: 150-mL beaker 400-mL beaker 250-mL Erlenmeyer flask 50-mL buret 50-mL graduated cylinder 100-mL graduated cylinder