An unknown liquid (A) showed no IR absorption between 1500 and 2500 cm^{-1}. Similarly there was...
Question:
An unknown liquid {eq}(A) {/eq} showed no {eq}IR {/eq} absorption between {eq}1500 {/eq} and {eq}2500 \ cm^{-1}. {/eq} Similarly there was no absorption above {eq}3000 \ cm^{-1}. {/eq} Compound {eq}A {/eq} reacted with alcoholic silver nitrate to give cloudiness after serval minutes and it also reacted with sodium iodide in acetone to give a precipitate after several minutes. What conclusion can be made about the identity of compound {eq}A {/eq}?
IR peaks and Alkyl halide :
IR (infrared) is a type of spectroscopy used to determine the structure of the unknown compound and also the purity of the compound formed.
It is mainly used to detect the functional groups.
Alkyl halide that is carbon halogen bonds appear at 500-600{eq}cm^{-1} {/eq} and for fluorine it is around 1000{eq}cm^{-1} {/eq}
Answer and Explanation: 1
As the unknown compound has no IR peak between 1500 to 2500 {eq}cm^{-1} {/eq}, that means there is of carbon-carbon double bond and triple bond. Also the carbonyl and cyanide functional groups is absent.
Also, there is no peak over 3000{eq}cm^{-1} {/eq} that suggest it does not have alcohol and amines as functional group.
This suggest that there is a possibility of alkyl halide or a simple hydrocarbon.
Now, on reacting with alcoholic silver nitrate it produces cloudiness suggets it can be a alkylbromide, as alkyl iodide produces instant precipitate and a chloro compound takes really long time.
Also the alkyl group can be secondary as tertiary produces instant precipitate and primary takes long time.
Now reaction with sodium iodide gives precipitate that means chlorine or bromine is replaced by iodine.So the halide can be bromine or chlorine.
And the reaction is fast for primary halides.
The reactions taking place can be -
![]() |
Ask a question
Our experts can answer your tough homework and study questions.
Ask a question Ask a questionSearch Answers
Learn more about this topic:

from
Chapter 2 / Lesson 8Learn about the alkyl halide structure and the definition of halide. See alkyl halide examples and find out more about their reactions in this engaging lesson.
Related to this Question
- An unknown solution gave a red flame and no precipitate with any of the reagents in the solubility test. The halide test gave a faint yellow color. Write the name and formula of the dissolved substance in the unknown solution.
- Sample of silver metal is suspected to be contaminated with zinc. A 0.2365 g portion of this metal is dissolved in nitric acid and the silver ions precipitated with excess aqueous NaCl. After filterin
- A solution containing an ionic compound is subjected to anion and cation confirmation tests, providing the following results. Addition of silver nitrate: a bright yellow precipitate formed Flame test: a purple color was observed Identify the ionic compoun
- If a precipitate is identified as a water-insoluble compound, it will always be: a) a colorless liquid. b) insoluble in water each time it is found in water. c) a gas. d) the product of a reaction. e) a substance whose color has changed.
- Why does the reaction of 2-bromo-2-methylbutane and ethanolic solution of silver nitrate interfered by the presence of water in the sodium iodide in acetone reagent?
- A solution containing an ionic compound is subjected to the anion and cation confirmation tests, providing the following results: Addition of silver nitrate: a bright yellow precipitate formed Flame test: a purple color was observed Identify the ionic com
- An unknown compound is tested with several reagents, yielding the following results; DNP test: A thick, yellow precipitate formed Tollens test: No precipitate or mirror was detected Iodoform test: A
- An unknown sample produces a reddish precipitate upon reaction with 2,4-dinitrophenylhydrazine reagent, no color change with Schiff's reagent, and a yellow precipitate when mixed with iodine and base.
- Absorption is usually measured at a wavelength where: A. the analyte has a weak absorption. B. the analyte has an unknown absorption. C. the analyte has no absorption. D. the analyte has a strong absorption.
- A solution containing an ionic compound is subjected to the anion and cation confirmation tests performed in this experiment. Addition of silver nitrate: a bright yellow precipitate formed Flame tes
- An unknown solution gives a brick-red flame test. The solution produces a white precipitate with ammonium carbonate, ammonium sulfate, and ammonium phosphate after heating. Silver nitrate is added to
- In photography, unexposed silver bromide is removed from film by soaking the film in a solution of sodium thiosulfate, Na_2S_2O_3. Silver ion forms a soluble complex with thiosulfate ion, S_2O_3^{2-}, that has the formula Ag(S_2O_3)_2^{3-}, and formation
- A silver coin has a mass of 2.50 g and is analyzed for silver by dissolving in dilute nitric acid, and precipitating silver as solid AgCl and weighing this. If the precipitate weighs 2.99 g, what perc
- An unknown solution gives a brick red flame test with flashes of yellow. The unknown gives a white precipitate with ammonium carbonate and ammonium phosphate, but no reaction with ammonium sulfate. th
- A student was assigned a colorless unknown. The student added five drops of 1.0 M barium chloride solution to 1.0 mL of the unknown solution. A white precipitate formed. In a second experiment, the student added two drops of 0.5 M NH3 solution to 1.0 mL o
- If phenolphthalein is used as an indicator for titrating Ca(OH)2 with titrant HCl instead of methyl orange, which is the recommended indicatory, would the reported solubility product for calcium hydroxide be too high, too low, or unaffected? Explain.
- Treatment of compound E (molecular formula C_4H_8O_2) with excess CH_3CH_2MgBr yields compound F (molecular formula C_6H_{14}O) after protonation with H_2O. E shows a strong absorption in its IR spectrum at 1743 cm^{-1}. F shows a strong IR absorption at
- The compound sodium thiosulfate pentahydrate, Na2S2O3 5 H2O, is important commercially to the photography business as "hypo," because it has the ability to dissolve unreacted silver salts from phot
- A salt gives black ppt with its group reagent which dissolves in diluted nitric acid. The above heated solution turns into blue on addition of ammonium hydroxide.This blue solution is acidified and treated with K4[Fe(CN)6] is added to obtain a chocolate p
- An unknown carbohydrate solution tested positive for the Molisch reagent, had no reaction with I_2, produced a red precipitate within 2-3 minutes with the Barfoed reagent, turned cherry red with the Seliwanoff reagent and produced a muddy brown-gray produ
- A BaSO_4 slurry is ingested before the gastrointestinal tract is x-rayed because it is opaque to x-rays and defines the contours of the tract. Ba^2+ ion is toxic, but the compound is nearly insoluble.
- An unknown sample of C u 2 + gave an absorbance of 0.263 in an atomic absorption analysis. Then, 1.00 mL of solution containing 133.00 ppm C u 2 + was mixed with 91.00 mL of unknown, and the mixture was diluted to 100.00 mL in a volumetric flask. The
- It is suspected that a water-insoluble solid unknown is an amine. Which of the following would be useful in confirming the suspicion? (a) 6 M HCl solution (b) 3 M NaOH solution (c) Red litmus paper
- An unknown compound[{Image src='img263848309298043248520.jpg' alt='' caption=''}] X has the molecular formula C_7H_13OBr. Compound X shows a strong peak in its IR spectrum in its IR spectrum at 1700 c
- An unknown sample is analyzed for iodide by oxidizing the iodide ion to iodate ion, according to the unbalanced reaction Br_2 +I^- \to Br + IO_3^-. The iodate formed is then precipitated as Ba(IO_3)_2, dried and then weighed. \\ 1. Balance the first reac
- An unknown sample does not react with 2,4-dinitrophenylhydrazine reagent, but a color change is observed on reaction with ceric nitrate reagent.
- A piece of zinc metal was added to an aqueous solution of lead (II) nitrate. After some time it was observed that the zinc metal appeared to fall apart and a solid had accumulated at the bottom of the
- An unknown sample of Cu^{2+} gave an absorbance of 0.262 in an atomic absorption analysis. Then 1.00 mL of a solution containing 100.0 ppm Cu^{2+} was mixed with 95.0 mL of the unknown, and the mixtu
- 3. A student, following the procedure in this experiment, studied the response of red food dye to visible light and analyzed a stock solution of red food dye of unknown concentration. A series of dilu
- Photogray lenses incorporate small amounts of silver chloride in the glass of the lens. When light hits the AgCl particles, the following reaction occurs: AgCl to Ag + Cl. The silver metal that is for
- Students often notice that the pale pink phenolphthalein color disappeared from his or her titrated samples after a few minutes. explain why does this happen with the a chemical equation?
- Silver bromide is used to coat ordinary black-and-white photographic film, while high-speed film uses silver iodide. a. When 66.4 mL of 5.00 g/L AgNO3 is added to a coffee-cup calorimeter containing 66.4 mL of 5.00 g/L NaI, with both solutions at 25 degre
- Qualitative analysis flow chart for an unknown solution which contains Na+, Pb2+, Cu+2, and Bi3+. Write "not observed' in any box that relates to a single ion that is not present in the unknown.
- An unknown compound has a molecular formula of C8H14O. The IR spectrum of this compound has two important signals: one at 1715 cm-1 (strong) and one at 1675 cm-1 (medium). This compound absorbs light
- A student was investigating the properties of a liquid L. He found that it turned phenolphthalein indicator red, but when a piece of litmus paper was dipped into liquid L, it turned blue. Which of these liquids could it be? a. aqueous ammonia b. lemon jui
- An experiment to extract an acidic and neutral compound from an unknown compound. The compound is dissolved in diethyl ether and transferred to a separatory funnel. The NaOH (aq) is then added to the separatory funnel and the salt of the acid is drained.
- Keeping in mind that aqueous the copper(II) ion is blue and the aqueous zinc ion is colorless, predict what you would observe over a several-day period if: A strip of Zn is placed into a beaker containing aqueous zinc ions.
- Missy Mae performs a flame test on the unknown compound, which reveals a lilac color. An aqueous solution of the unknown compound yields the following results: i. forms no precipitate when 0.10 M sod
- You have a protein solution with unknown concentration. Its extinction coefficient at 280 nm is 23,000 M-1cm-1. You measure the absorption at 280 nm in a 1 cm path-length cuvette and get 0.3. What is
- A 0.3991 g of an unknown containing chloride is dissolved and precipitated with 43.98 mL of excess 0.1056 M AgNO_3. A sintered glass crucible weighing 23.4101 g is used to filter out the resulting AgCl. The new weight of the dried crucible is 23.9622 g. C
- 1. You found an unlabeled powder in the General Chemistry Lab. You dissolved it water and performed a flame test. The flame turned a bright yellow color. You then measured the electrical conductivity
- Treatment of 2-butanone with strong base followed by CH_3l forms a compound Q which gives a molecular ion in its mass spectrum at 86. The IR spectrum shows an absorption at 3000, 2950, 2870, and 1715
- the flask shown here contains 0.211 g if acud and a few drop of phenolpthalein indicator dissolved in water. the contains 0.260 M NaOH
- A solid laboratory unknown contains two substances, lead (II) carbonate and potassium carbonate. A 5.000 g sample of this unknown was treated with aqueous nitric acid to dissolve it; then, after further treatment to adjust the acidity, it was treated with
- A sample weighing 0.0123 g was dissolved in concentrated nitric acid to convert all of the arsenic to arsenate. The solution was diluted 10 times and excess silver added to precipitate silver arsenate (Ag_3 \cdot AsO_4), which was collected, dried, and we
- A photometer with a linear response to radiation gave a reading of 690 mV with a blank in the light path and 169 mV when the blank was replaced by an absorbing solution. Calculate: A) the transmittance and absorbance of the absorbing solution. B) the expe
- A sulfide ion can be confirmed by adding few drops of NaOH and a sodium nitroprusside solution to a sodium carbonate extract, which results in a violet color. The violet color is due to a) Na2[Fe(CN)5NO] b) Na4[Fe(CN)5NOS] c) Na3[Fe(CN)6]
- When setting up their experiment, a student discovered that the solution in their flask turned bright pink upon adding 2 drops of the indicator, even before beginning the titration. What do you suspec
- Metals bond with halogens to form colorless metal halides. During an experiment, bromine water was added to a solution of potassium iodide. A record of the experiment is shown. Reactants color: Br2 = light orange solution, KI = colorless solution Color of
- NaOH was dissolved in MgCl2, and the color turned dark pink from white. Then HCl was added and the color changed back to white. The reaction you observed was Mg.OH.2 gives to Mg^++ 2OH^ . Compare the colors you observed in the experiment and answer the fo
- An unknown solid compound containing Pb2+ ion was mixed with 15 mL of 2.0 M HNO3. The mixture bubbled profusely. After complete reaction, it was found that 0.020 moles of CO2 were produced and the original solid was completely consumed. a) What is the che
- A light-absorbing substance was exposed to 100 W of 490 nm light for 45 min. After exposure of 300 mmol of A to light, 2.28 mol of B was formed. The intensity of the transmitted light was 40% of the intensity of the incident light. As a result of irradiat
- Suppose that for the preparation of the stock solution of borax, the solid borax reagent is contaminated with a water-soluble substance that does not react with hydrocholoric acid and does not have an
- A compound A (C_22H_27NO) is insoluble in acid and base but reacts with concentrated aqueous HCl and heat to give a clear aqueous solution from which, on cooling, benzoic acid precipitates. When the supernatant solution is made basic, a liquid B separates
- You tested an unknown compound in the laboratory and had the following observations: no reaction with bromine until irradiation with UV light. Negative test results when mixed with KMnO_4.
- Keeping in mind that aqueous the copper(II) ion is blue and the aqueous zinc ion is colorless, predict what you would observe over a several-day period if: A strip of Cu is placed into a beaker containing aqueous zinc ions.
- How would the observed timing for precipitate formation change if 2-chlorobutane was subjected to silver nitrate in 1:1 ethanol:water (as opposed to 100% ethanol) ?
- In a spectrophotometric experiment, 84.9% of the incident light is absorbed by the solution under investigation. If the solution is of concentration 0.069 mol dm^-3, and the path length of the cell is 12.5 mm, what is the molar absorption coefficient of t
- For the standardization of the NaOH solution, the endpoint was consistently reproduced to a faint pink color. However, the endpoint for the titration of the acid solution was consistently reproduced to a dark pink color. Will the reported molar concentrat
- A silver recovery unit can process 1500 L of photographic silver waste solution per day. Adding excess solid sodium chloride to a 500 mL sample of the waste gives a white precipitate that, after filtration and drying, consists of 3.73 g of AgCl. a. Write
- The black silver sulfide discoloration of silverware can be removed by heating the silver article in a sodium carbonate solution in an aluminum pan. The reaction is
- An unknown compound, C_5H_{10}O_2 had a strong absorbance in its IR spectrum at 1725 cm^{-1} and gave the following proton NMR data: a) doublet, at 1.23 ppm (6H) b) singlet, at 2.10 ppm (3H
- An unknown compound is isolated. Mass spectrometry shows M and M+2 peaks at 75.5 and 77.5, at relative abundances of 3:1. IR showed a strong peak at 2261 cm
- A student does a standard addition experiment by pipetting 25 mL of an unknown, adding ferrous ion spikes and reagents, into a 100 mL volumetric flask and making up to the mark. The equation of the li
- You and your partner were carrying out flame tests side-by-side. Your partner tested a known solution of RbNO3 and observed a purple flame. You tested an unknown sample and observed a red flame. What can you say about the cation present in the unknown bas
- Instant cold packs, often used to ice athletic injuries on the field, contain ammonium nitrate and water separated by a thin plastic divider. When the divider is broken, the ammonium nitrate dissolves according to the following endothermic reaction. NH4NO
- Instant cold packs, often used to ice athletic injuries on the field, contain ammonium nitrate and water separated by a thin plastic divider. When the divider is broken, the ammonium nitrate dissolves according to the following endothermic reaction: NH_4N
- An analyst prepares a stock Cu(NO_{3})_{2} solution by dissolving 1.0 g of Cu(NO_{3})_{2} in 1.0 L of 2 % nitric acid (HNO_{3}). A series of standards were made by diluting this solution and assessed for their transmittance using a visible spectrophotomet
- A sample of a pure compound (CH_3)_4 NBrx weighing 0.0962 g was dissolved and treated with a reducing agent to ensure that all the bromine was present as Br^-. A precipitate of silver bromide weighing 0.1730 g was obtained. Calculate the value of x in t
- Instant cold packs, often used to ice athletic injuries on the field, contain ammonium nitrate and water separated by a thin plastic divider When the divider is broken, the ammonium (titrate dissolves
- Nitrate levels in well water can be determined spectrophotometrically through a procedure that measures the intensity of absorbed light at 410 nm after the sample has been properly treated with phenol disulfonic acid. An unknown sample of 25.0 mL of well
- A student heated 1 g of a red-pink hydrated salt until all the water had been removed. She was left with 0.546 g of dark blue solid. Is it possible that the hydrated salt was bienerite, CoSO4 * 7H2O? Why or why not? Show calculations.
- A permanganate solution was standardized by titrating with sodium oxalate. A primary standard sodium oxalate (Na2C2O4) was accurately weighed into a conical flask and dissolved with 100 mL of 3 M sulphuric acid. Then the solution was titrated with the per
- A student is given a sample in lab which contains one of the ions listed below. After adding a few drops of solution to part of the unknown sample, the student got a greyish precipitate. After adding
- Experiment for SN1 reactions in silver nitrate/ethanol. 1. 1-chlorobutane 2. 1-bromobutane 3. 2-chlorobutane 4. 2-bromobutane 5. bromocyclohexane 6. 2-chloro-2-methylpropane (t-butyl chloride)
- An experimental cell is set up such that one half cell contains a solid silver electrode dipping into a saturated solution of silver oxalate. The oxalate ion comes from added sodium oxalate so that eq
- A chemist prepares a solution of mercury(II) iodide, HgI2, by measuring out 0.0139 g of mercury(II) iodide into a 400 mL volumetric flask and filling the flask to the mark with water. Calculate the concentration in mol/L of the chemist's mercury(II) iodid
- when p-ethenlybenzoic acid is treated with mercuric acetate and water followed by reduction with sodium borohydride, the IR spectrum of the product shows a strong broad absorption at 3400cm-1. the iso
- In the chemical laboratory, the Tollen s test for the presence of reducing sugars (say, in a urine sample) involves treating the sample with silver ions in aqueous ammonia. The result is the formation of a silver mirror within the reaction vessel if a red
- Instant cold packs used to ice athletic injuries on the field contain ammonium nitrate and water separated by a thin plastic divider. When the divider is broken, the ammonium nitrate dissolves according to the endothermic reaction: NH4NO3(s) -- NH4+(a
- 1. In the photographic developing process, silver bromide is dissolved by adding sodium thiosulfate. AgBr(s) + 2Na2S2O3(aq) arrow Na3Ag(S2O3)2(aq) + NaBr(aq) If you want to dissolve 0.194 g of AgBr, w
- Part A Barium sulfate, BaSO4, is used in medical imaging of the gastrointestinal tract because it is opaque to X rays. A barium sulfate solution, sometimes called a cocktail, is ingested by the patien
- A Precipitate is: a. A solid formed from a chemical reaction b. A rocky edge c. A substance dissolved in a liquid e. A change in solution colour during a chemical change
- A student is given a sample in the lab which contains one of the ions listed below. After adding a few drops of solution to part of the unknown sample, the student got a greyish precipitate. After add
- Aluminum sulfate, known as cake alum, has a remarkably wide range of uses, from dyeing leather and cloth to purifying sewage. In aqueous solution, it reacts with base to form a white precipitate. (a)
- Ghoton is given an unknown solution that only contains one of the two listed cations. Describe a simple test to distinguish between aqueous solutions of the following cations. State the distinguishing outcomes of the test and the indication of which catio
- A solution containing the complex formed by Bi(II) and thiourea has a molar absorptivity of 9.32 x 10^3 L mol-1 at 470 nm. a) What is the absorbance of a 6.24 x 10-5 M solution of the complex at 470 nm in a cell of 1.00-cm light absorption path length?
- Which of the following can affect the validity of absorbance values? (a) Stray light (b) Monochromatic device (c) Unstable chromophore (d) Nonspecific absorption.
- Treatment of 2-methylpropanenitrile ((CH_3)_2CHCN) with CH_3CH_2CH_2MgBr, followed by aqueous acid, affords compound V, which has molecular formula C_7H_14O. V has a strong absorption in its IR spectrum at 1713 cm^-1, and gives the following ^1H NMR data:
- An unknown compound was found to be soluble in concentrated sulfuric acid; however, the 2,4-DNP, chromic acid, and potassium permanganate gave negative results. The only positive result detected was t