Consider the following compounds that vary from nearly nonacidic to strongly acidic. Draw the conjugate bases of these compounds, and explain why the acidity increases so dramatically with substitution by nitro groups.CH4 CH3NO2 CH2(NO2)2 CH(NO2)3 pKa ≅ 50 pKa = 10.2 pKa = 3.6 pKa = 0.17

Rank the following compounds in order of increasing acidity

3. According to the Evan's pKa table, phenol has a pka of 9.95. p-Nitro and m-nitrophenol have pKas of 7.14 and 8.35 respectively. Using resonance structures, explain the observed trends in the acidity of these molecules. OH .NO2 OH HO

Arrange these phenolic compounds in order of increasing acidity. Least acidic Most acidic Answer Bank НО -N+ Но CI Но HO

Determine whether the following reaction is an example of a nucleophilic substitution reaction: 8+ + H2O Molecule A Molecule B OH ++H Is this a nucleophilic substitution reaction? If this is a nucleophilic substitution reaction, answer the remaining questions in this table. What word or two-word phrase is used to describe the role Molecule A plays in this reaction? ☐ What word or two-word phrase is used to describe the role Molecule B plays in this reaction? What word or two-word phrase is used to describe the role of the carbon labeled with the 6+ symbol? What word or two-word phrase is used to describe the role of the atom or group highlighted in red? ☐ ☐ ☐ Yes No

Explain the differences in pKa (vs. benzoic acid) of these substituted benzoic acids based on fundamental chemical principles (not just what pKa means).

Step 1: The carboxylic acid contains six carbons and the starting material should be an alkyl halide of five carbons or less, so you should look for a method of generating carboxylic acids by adding a carbon. One method of synthesizing carboxylic acids is from the hydrolysis of nitriles, which can be formed by substitution of alkyl halides. Identify the structure that contains a nitrile. OCH₂CH=NH OCH,CEN RCH=CHNH, OCH, CH₂NH,

From each pair, select the stronger base. Then draw the conjugate acid of the strong base below. CH3CH20 or CH3CEC • You do not have to consider stereochemistry. You do not have to explicitly draw H atoms. • You do not have to include lone pairs in your answer. C opy aste

Indicate which is more acidic: 4-nitrophenol or 4-chlorophenol. Explain the reason.

Phenol (hydroxybenzene) behaves as a weak acid. a) Write out the equilibrium equation for its partial dissociation in water. b) Write out the expression for the acid dissociation constant, Ka. d) Draw the conjugate base of phenol and show how it is stabilised by resonance. e) Compare and explain the acidity of phenol (p = 9.9) with that of: cyclohexanol (pk = 16.0) 3-fluorophenol (pK₁ = 9.3) 4-acetylphenol (pK, = 8.1)