Methyl violet belongs to a large class of chemicals called acid-base indicators. These substances change color in solution when the hydrogen ion concentration changes. The actual formula for methyl violet is quite complicated, so we'll use the abbreviation HMV. This notation suggests that methyl violet is itself a weak organic acid. In solution, methyl violet dissociates as follows: HMV(ag)-yellow + H*(ag) + MV(ag)-violet (2) According to the video : (a) What are the colors of methyl violet in an acidic medium , and in a neutral environment ? (b) What was the acidic pH_ What was the neutral pH_ (c) Predict what will happen to the color if HCl solution is added to the reaction system ? (d) What will happen if NaOH is added ?

Methyl violet belongs to a large class of chemicals called acid-base indicators. These substances change color in solution when the hydrogen ion concentration changes. The actual formula for methyl violet is quite complicated, so we'll use the abbreviation HMV. This notation suggests that methyl violet is itself a weak organic acid. In solution, methyl violet dissociates as follows: HMV(ag)-yellow + H*(ag) + MV(ag)-violet (2) According to the video : (a) What are the colors of methyl violet in an acidic medium , and in a neutral environment ? (b) What was the acidic pH_ What was the neutral pH_ (c) Predict what will happen to the color if HCl solution is added to the reaction system ? (d) What will happen if NaOH is added ?

Chemistry: Principles and Practice

3rd Edition

ISBN:9780534420123

Author:Daniel L. Reger, Scott R. Goode, David W. Ball, Edward Mercer

Publisher:Daniel L. Reger, Scott R. Goode, David W. Ball, Edward Mercer

Chapter16: Reactions Between Acids And Bases

Section: Chapter Questions

Problem 16.9QE

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The reaction just described is reversible. Deprotonation of the conjugate acid of an organic base by water provides another example of simultaneous making and breaking of sigma bonds. Thus, in the deprotonation of anilinium ion by water, the base is water, which has unshared electrons on the ________ atom. The acid is ________ ion. A pair of ________ electrons on the oxygen atom of water is pushed toward the ________ atom. Simultaneously, the pair of ________ electrons between the hydrogen and ________ atom of the anilinium ion is pushed toward the ________ atom. Thus, the oxygen- ________ sigma bond is made and a hydrogen- ________ sigma bond is broken. The nitrogen atom, which possessed a positive charge, is now ________, and the oxygen atom, which was neutral, now possesses a formal ________ charge.
The simplest amino acid is glycine, H2NCH2CO2H. The common feature of amino acids is that they contain the functional groups: an amine group, -NH2, and a carboxylic acid group, -CO2H. An amino acid can function as either an acid or a base. For glycine, the acid strength of the carboxyl group is about the same as that of acetic acid. CH3CO2H, and the base strength of the amino group is slightly greater than that of ammonia, NH3. (a) Write the Lewis structures of the ions that form when glycine is dissolved in 1 M HCl and in 1 M KOH. (b) Write the Lewis structure of glycine when this amino acid is dissolved in water. (Hint: Consider the relative base strengths of the -NH2 and -CO2- groups.)
Write two BrnstedLowry acid-base reactions and show how they represent proton-transfer reactions.
. How is the strength of an acid related to the fact that a competition for protons exists in aqueous solution between water molecules and the anion of the acid?
Write the chemical equation and the expression for the equilibrium constant, and calculate Kb for the reaction of each of the following ions as a base. (a) sulfate ion (b) citrate ion
A solution of sodium cyanide, NaCN, has a pH of 12.10. How many grams of NaCN are in 425 mL of a solution with the same pH?
The pigment cyanidin aglycone is one of the anthocyanin molecules that gives red cabbage (Brassica oleracea var. capitata f. rubra) its characteristic red coloration. Many chemistry students have used this red cabbage indicator to study acid-base chemistry. Estimate tire pH range at which cyanidin agly-cone shows a color change. Anth-H(aq) Anth(aq) + H+ (aq) Ka = 1.3 107
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Write the Lewis structures of the reactants and product of each of the following equations, and identify the Lewis acid and the Lewis base in each: (a) CS2+SHHCS3 (b) BF3+FBF4 (c) I+SnI2SnI3 (d) Al(OH)3+OHAl(OH)4 (e) F+SO3SFO3
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Here is ph of the molarity of butyl chloride (C,H,CI) in a reaction vessel during a certain chemical reaction. Use this graph to answer the questions in the table below. у 0.030- 0.0247 olo 0.020- Ar M 0.015- 0.010- 0.005- 500 1000 1500 2000 2500 3000 seconds created x10 Is C,H,Cl being created or destroyed by the chemical destroyed reaction? neither created nor destroyed If C,H,Cl is being created or destroyed, what is the rate at which it is being created or destroyed 1200 seconds after the reaction starts? Explanation Check © 2022 McGraw Hill LLC. All Rights Reserved. Terms of Use | Privacy Center | Accessibility