A clock reaction is run at 20°C with several different mixtures of iodide, sodium bromate and...
Question:
A clock reaction is run at 20°C with several different mixtures of iodide, sodium bromate and acid, to form iodine. Thiosulfate is used to react with the iodine formed initially. Starch indicator is added to form a blue color when all the thiosulfate has been used up and the iodine concentration begins to rise. Mixtures with the following initial concentrations are used:
| Run number | [I-] | [BrO3-] | [H+] |
|---|---|---|---|
| 1 | 0.002 | 0.008 | 0.02 |
| 2 | 0.002 | 0.016 | 0.02 |
| 3 | 0.004 | 0.008 | 0.02 |
| 4 | 0.002 | 0.008 | 0.04 |
[S2O32- ] is equal to 0.0001M in each reaction mixture. The rate law is Rate = {eq}k [I^-]^a[BrO_3^-]^b[H^+]^c {/eq}. The reaction time is 30 s in run 1, 30 s in run 2, 15 s in run 3, and 30 s in run 4. Calculate a, b, and c in the rate law.
Clock Reaction:
A clock reaction is a chemical reaction that can be used as a clock, meaning that the reaction can be used to measure time. That is possible because the observable changes of the reaction happen after a period of time that can be predicted relatively easily.
Answer and Explanation: 1
Become a Study.com member to unlock this answer! Create your account
View this answerThe order of the reaction for each chemical species is calculated by comparing the rate of the reaction for two runs and the concentrations of the...
See full answer below.
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:
Get access to this video and our entire Q&A library
Rate of a Chemical Reaction: Modifying Factors
from
Chapter 12 / Lesson 1
46K
Learn about the rate of reaction. Understand the factors affecting the rate of reaction and see how catalyst, concentration, temperature and surface area affect it.
Related to this Question
- A clock reaction is run at 20 �C with sev[{Image src='img20401705385059449876496.jpg' alt='' caption=''}]eral different mixtures of iodide, sodium bromate and acid, to form iodine. Thiosulfate is used
- A mixture of acidified K 2 C r 2 O 7 and 10% K I is titrated against N a 2 S 2 O 3 (Sodium thiosulphate) solution using starch indicator. What is the color of the reaction mixture at the end point? (A) Yellow (B) Blue (C) Green (D) Colorless
- 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.
- Questions from an article about the iodine clock reaction using these reagents: Potassium iodate (KIO3), Sodium bisulfite (NaHSO3), Sulfuric acid (H2SO4) - this is the catalyst, and a starch indicator
- A student studied the clock reaction described in this experiment. They set up Reaction Mixture 4 by mixing 10. mL. of 0.010 M Na_2S_2O_3, 10. mL of 0.040 M KBrO_3, and 20. ml of 0.10 M HCI using the
- A mixture of starch and iodine mixture turns blue because (a) Starch is blue (b) Iodine is blue (c) Starch is a chain of glucose molecules (d) iodine interacts with coiled starch molecules (e) Copper (II) ion is reduced to copper (I) ion
- In the kinetic analysis of this experiment for the reaction of iodide ion with hydrogen peroxide, state the purpose for each of the following solutions. (a) Deionized water (b) Buffer solution (c) Starch solution (d) Sodium thiosulfate solution
- A reaction mixture was made up in the following way: 10 ml 4.0M acetone, 5.0 ml 1.0M HCl, and 10 ml 0.005M iodine. If the reaction order is zero with the respect to iodine, how long will it take for the iodine color to disappear?
- Solid iodine, contaminated with salt, was heated until the iodine vaporized. The violet vapor of iodine was then cooled to yield the pure solid. Solid iodine and zinc metal powder were mixed and ignited to give a white powder. Identify each physical chang
- 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
- In an experiment, 5.00 mL of 0.1440 mol L^1- aqueous KIO3 was reacted with an excess of aqueous iodide and the molecular iodine I2, This was titrated against 0.1000 mol L^1- aqueous S2O3^2-. The equat
- The components listed on the label of a typical box of salt are sodium chloride, sodium silicoaluminate, sodium thiosulfate, and potassium iodide. On the basis of its ingredients, would you conclude that table salt is a substance or a mixture? Explain you
- Consider the reaction between iodine gas and chlorine gas to form iodine monochloride: I2(g)+Cl2(g) \leftrightarrow 2ICl(g), K_p = 81.9 (at 298 K) A reaction mixture at 298 K initially contains PI_2 = 0.30 atm and PCl_2 = 0.30 atm. What is the partial
- 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
- In an analytical determination of arsenic, a solution containing arsenious acid, H3AsO3, potassium iodide, and a small amount of starch is electrolyzed. The electrolysis produces free iodine from iodide ion, and the iodine immediately oxidizes the arsenio
- Sodium thiosulfate (Na_2S_2O_3) can be used to reduce Br_2 to harmless Br^- and is in turn oxidized to tetrathionate S_4O_6^2-. You will use it to clean up any bromine spilled or left in your apparatus. Write
- A student mixes solutions of potassium iodide and lead nitrate in a test tube and notices that a yellow solid forms and settles to the bottom of the test tube. The student just performed a type of reaction.
- Calculate the iodine number: a. 0.115 g of an unknown lipid b. 10.0 mL of Hanus iodine solution c. 0.09787 M sodium thiosulfate (Na2S2O3)
- 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
- Iodine can be separated from a mixture of Iodine and Potassium Chloride by ................... . a) Filtration b) Sublimation c) Distillation d) Sedimentation
- Gaseous iodine pentafluoride, IF_5, can be prepared by the reaction of solid iodine, I_2, and gaseous fluorine, F_2. A 5.00 L flask containing 10.0 g I_2 is charged with 10.0 g F_2, and the reaction p
- The student takes a 2.00mL aliquot of the bleach solution and adds 1.00g of potassium iodide and 20.0mL of water. After buffering the solution, he then titrates the solution with 0.1153 M sodium thiosulfate solution and reaches the equivalence point after
- 104g sample of impure was acidified and analysed using excess iodine ion. The reaction is . Then is titrated with 0.300M
- Synthesis of dimedone. Sodium methoxide in mthanol and dimethyl propanedioate are added to a flask, when dissolved mesityl oxide is added and the reaction mixture is refluxed for an hour. Then a rotar
- A student was studying the clock reaction described in this experiment: 6I-(aq) + BrO3-(aq) + 6H+(aq) --> 3I2 (aq) + Br-(aq) + 3H2O(l) She measured that the reaction took 74.7 seconds to see a color
- How would you usually prepare a starch indicator solution for iodine titrations? Can the solution be stored for a few months in the fridge? Sometimes the starch indicator solution in the fridge has tu
- In an experiment to calculate the K s p of calcium iodate ( C a ( I O 3 ) 2 ), a 10 mL solution of a saturated solution of calcium iodate was titrated against 0.0250 M solution of sodium thiosulfate ( N a 2 S 2 O 3 ) using starch indicator. The end poin
- Iodine solution, which contains a suspension of I_2 (s), has a brown color, which of the following metals will not cause an iodine solution to change color? (a) Ni (s) (b) Cu (s) (c) Ag (s) (d) Mg (s)
- A mixture of 0.600 mol of bromine and 1.600 mol of iodine is placed into a rigid 1.000 L container at 350 degrees Celsius. Br_2 (g) + I_2 (g) \leftrightharpoons 2IBr (g) When the mixture has come to equilibrium, the concentration of iodine mono bromide i
- When a solution containing I^- is mixed with a solution containing Cl_2, Cl^- and I_2 appear in the solution. What does this tell you about the reactivity of the element chlorine relative to that of the element iodine? a. Iodine is more reactive than chlo
- 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
- Identify the physical and chemical properties of iodine that are cited below: Iodine is a solid having somewhat lustrous, blue-black crystals. The crystals vaporize readily to a violet-colored gas. Iodine combines with many metals. For example, aluminum
- A procedure for iodometric determination of Cu in brass has two parts: standardization of a thiosulfate solution and assay of the copper. In the standardization of the thiosulfate solution, a known amount of iodine is created from KIO₃ and excess i
- If you had an unknown that could contain both bromine and iodine, you must test for iodine, and if positive, use a different test for bromide. Why?
- Two colorless solutions are mixed in a stoppered flask. As the reaction proceeds, the resulting solution turns red, and a colorless gas is formed. After a few minutes, no more gas is evolved but the r
- 1. Colour of original K2Cr2O7 solution: orange Colour after the addition of NaOH: Yellow Colour after the addition of HCl: Orange Direction in which equilibrium is shifted by the addition of: NaOH:
- When chlorine gas is bubbled into a solution of sodium bromide, the sodium bromide reacts to give bromine, a red-brown liquid, and sodium chloride (table salt). A solution was made by dissolving 20.6
- A student mixed the following reactants: 10.0 mL of 0.10 M KI, 10.0 mL of 0.0010 M Na2S2O3, 20.0 mL of 0.040 M K2S2O8, and 10.0 mL of 0.10 M HCl. It took about 75 seconds for the mixture to turn blue.
- Luminol is a compound that can undergo a chemiluminesence reaction with peroxide and catalyst to give blue light. In the daylight it is hard to see this light, though. However, glowsticks are glowing so much that they are also visible in the daylight. And
- Suppose you have placed 20 drops of sodium bisulfate and 3 drops of thymol blue into a well in your well plate. As you add potassium sulfate to the solution, what happens? A. The mixture color changes from red to orange. B. The color becomes faint due to
- At a certain temperature, bromine and nitric oxide react to form nitrosyl bromide: Br2(g) + 2 NO(g) arrow 2 NOBr(g). When initial amounts of Br2, NO, and NOBr are mixed, the concentration of NOBr incr
- 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.
- I took fresh orange juice and added 40.0 ml to a flask then added 1.0ml of a starch indicator solution. I added 0.015 M of iodine solution to a 50 ml burette. After 5.67 ml had been dispensed, it changed from orange to dark orange. The volume of the flask
- An unknown sample does not react with 2,4-dinitrophenylhydrazine reagent, but a color change is observed on reaction with ceric nitrate reagent.
- What would the procedures be in order to separate a mixture of crystalline iodine, potassium bromide, granular iron (100 mesh) and aluminum oxide powder?
- You are given a mixture of iodine solid and sodium chloride ( Hint: iodine is not soluble in water), what method(s) can you use to separate the mixtures? 1.) Filtration 2.) Evaporation 3.) Centrifugation
- What possible chemicals can test the presence of limonene except for bromine water and potassium permanganate?
- We performed an experiment on UV-Vis Spectrometry, by testing the absorbance of KMnO_4 and KCr_2O_7 solutions at different concentrations. We prepared the dichromate solutions
- Lab work was done on the bromination of acetanilide, aniline, and anisole. One of three compounds was dissolved in glacial acetic acid. A bromine/hydrobromic acid mixture was added and stirred for 20 minutes
- 1.) A reagent or test that could be used to distinguish between I-pentene and l-pentane would be: i. Bromine in carbon tetrachloride. ii. Dilute aqueous potassium permanganate. iii. Chlorine in car
- A chemical "breathalyzer" test works because ethyl alcohol in the breath is oxidized by the dichromate ion (orange) to form acetic acid and chromium(III) ion (green). The balanced reaction is 3C2H5OH(aq)+2Cr2O7^2-(aq)+2H^+ gives to 3HC2H3O2(aq)+4Cr^3+(aq)
- Under certain conditions, the substances hydrogen and iodine combine to form hydrogen iodide. If 28.9 grams of hydrogen and 3638.3 grams of iodine combine to form hydrogen iodide, how many grams of hydrogen iodide must form?
- Iodine monobromide, IBr, occurs as brownish-black crystals that vaporize with decomposition: The equilibrium constant Kc at 100 ^oC is 0.026. If 1.80 x 10^{-2} mol IBr is placed in a 1.10-L vessel at 100 ^oC, what are the molar concentrations of substanc
- 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
- 1.)What would be the effect of carrying out the sodium iodide in acetone reaction with the alkyldalides using an iodide solution half as concentrated? 2.)What would be the effect of carrying out the
- Methyl red has a pKa of 5.0 and is red in its acid form and yellow in its basic form.If several drops of this indicator are placed in a 25.0 -mL sample of HCl, what color will the solution appear? The
- In a series of experiments, a chemist prepared 3 different compounds that contain only iodine and fluorine and determined the mass of each element in each compound: mass of iodine (g) is 4.75, 7.64 and 9.41 in compounds 1, 2 and 3 respectively, mass of fl
- Chemiluminescence reactions actually occur very slowly in air. If you had a stoppered flask with basic luminol and then opened it to the air, would the chemiluminescence be more pronounced than with the flask stoppered? Why or why not?
- A mixture composed of 3-chlorobenzoic acid and acetanilide is added to a separatory funnel. Diethyl ether is added, and then aqueous sodium bicarbonate solution. What happens to the mixture?
- Gaseous iodine pentafluoride, IF5, can be prepared by the reaction of solid iodine and gaseous fluorine: I2(s) + 5F2(g) arrow 2IF5(g) A 5.10-L flask containing 10.2 g I2 is charged with 10.2 g F2, and
- __________ is an oxidation reaction. A) Ice melting in a soft drink. B) Table salt dissolving in water for cooking vegetables. C) Rusting of iron. D) The reaction of sodium chloride with lead nitrate to form lead chloride and sodium nitrate.
- In the kinetic analysis of this experiment for the reaction of iodide ion with hydrogen peroxide, state the purpose for each of the following solutions.
- When chlorine gas is bubbled into a solution of sodium bromide, the sodium bromide reacts to give bromine a red brown liquid and sodium chlorine. A solution was made by dissolving 20.0 g of sodium bro
- Sodium tetrathionate is formed when sodium thiosulfate reacts with iodine. Its composition is 17.01% Na, 47.46% S, and 35.52% O by mass. a) Determine its empirical formula. b) If the molar mass of sodium tetrathionate is 272, what is its actual formula?
- In the colorimetric (color producing) assay for iron used in this lab; potassium thiocyanate, KSCN, is added to produce a deep red colored precipitate. The lab outline suggests that H2O2 may be added
- The active agent in many hair bleaches is hydrogen peroxide. The amount of H_2O_2 in 14.5-g of hair bleach was determined by titration with a standard potassium permanganate solution: 2 MnO_4^-(aq) + 5 H_2O_2(aq) + 6 H^+(aq) to 5 O_2(g) + 2 Mn^{2+}(aq) +
- suppose you were given a sample of iodine crystals, a sample of antimony, and a sample of mixture of iodine and antimony that had been ground together to form a fine powder of uniform consistency. loo
- Suppose you were given a sample of iodine crystals, a sample of antimony, and a sample of a mixture of iodine and antimony that had been ground together to form a fine powder of uniform consistency. L
- The iodine test of starch was done with two samples containing 1) 10% HCl and 2) H_2O. The sample containing H_2O turned black, while the other didn't. Why did only one test positive?
- The active ingredient in hair bleaches is hydrogen peroxide, H 2 O 2 . The amount of H 2 O 2 in 14.8 g of hair bleach was determined by titration with a standard potassium permanganate ( K M n O 4 ) solution. Treat this reaction as you would an acid-ba
- Add the first chemical Na_2CO_3 to a test tube and then add the second chemical AgNO_3 until a change is observed. What is the colour of the chemical Na_2CO_3 before the mixture and the colour of AgNO_3 before the mixture, the available ions for Na_2CO_3
- The blue color of dextran blue solution is due to the well-known, blue complex formed between starches and iodine. If you only had the absorption spectrum of this solution, explain why its color could be predicted, based on the spectrum alone. In what par
- To determine the Ksp value of Hg2I2, a chemist obtained a solid sample of Hg2I2 in which some of the iodine is present as radioactive 131I. The count rate of the Hg2I2 sample is 5.0x10^11 counts per minute per mole of I. An excess amount of Hg2I2(s) is p
- When two solutions are mixed and a new color is observed, is this color change an indication that a chemical reaction has occurred? Explain.
- Identify these unknown organic compounds: 1. Silver Nitrate test: test with Nitric acid: The reaction mixture remains unchanged 2. Basic Hydrolysis Test: There was no change in the mixture after 2 hours of heating 3. Basic Hydrolysis: Test for ammonia:
- Ten drops of water are added to two small test tubes and to each is added one drop of iodine. The solution turns from a lighter yellow to a darker orange. To one of the test tubes some powdered magnesium is added and mixed well and centrifuged.
- 4. A sample of solid iodine is placed in a beaker. A rubber balloon is stretched over the top of the beaker. The iodine is then allowed to sublime (turn to gas). Using the following equation. ?E = q +
- In a lab experiment I added Br_2 to hydrocarbons cyclohexane, cyclohexene, and toluene. A loss of color would indicate a reaction took place. Only the cyclohexene lost color and turned clear.
- A 1.0-mL volume of 0.010 M H_2SO_3 is added to a mixture of 12 drops of 0.010 M HIO_3, 8 drops of deionized water, and 1 drop of starch solution. A color change occurred after 40 seconds. Assuming 25
- When HCI + blue dye are mixed, does it produce a green mixture or green precipitate?
- An 8.75-g sample of iron ore (mixture) is transformed to a solution of iron(II) sulfate, and this solution is titrated with 0.150 M K2Cr2O7 potassium dichromate. If it requires 67.8 mL of potassium dichromate solution to titrate the iron(II) sulfate solut
- A sample of 131 I was purified and then analyzed for iodine content. It was found that the sample was 99.8% pure. 25 hours later the sample was tested again
- In the standardization of potassium permanganate. 1) Why is is unnecessary to add an indicator during the titration? 2) Why is the solution of sodium oxalate acidified with sulfuric acid before titration? 3) Why is the solution of sodium oxalate heated to
- 2CrO4^2- (aq, yellow) + 2H3O^+ (aq) <---> Cr2O7^2- (aq, orange) + 3H2O( a) Describe the color change the student should observe after adding excess NaOH to the solution to the equilibrium mixture. b)
Explore our homework questions and answers library
Browse
by subject