Please help! One method to synthesize an ether is to react an alcohol with an al
ID: 491802 • Letter: P
Question
Please help!
One method to synthesize an ether is to react an alcohol with an alkylhalide. The reaction proceeds by and SN_2 mechanism with the alkoxide anion acting as the nucleophile, and the halogen as the leaving group. The following is an excerpt from a student's laboratory notebook (with some entries redacted): Which of the following should be added as reagent X in order to make the reaction work? a) NaCl b) NaI c) NaOH d) Na_2SO_4 e) CaCl_2 Calculate the number of grams of phenol to be used as set out in the scheme? a) 25.56 b) 2.56 c) 2.82 d) 0.0531 e) 18.82 Ethanol was a good choice of solvent in this reaction for a number of reasons. Which of the following statements about the solvent is FALSE? a) Ethanol will dissolve 1-iodobutane. b) Ethanol will dissolve phenol. c) Ethanol will dissolve low concentrations of the phenolate anion. d) Ethanol will not dissolve the product butylphenyl ether. e) The iodine containing by-product will be sparingly soluble in ethanol. If 3.56 g of product were recovered, what was the percentage yield? a) 87% b) 71.2% c) 0.712% d) 97% e) 9.7%Explanation / Answer
To make the ether by Wlliamson synthesis the phenol is to be converted to phenoxide ion using NaOH.
a) NaOH , option c is correct.
b) number of equivalents of phenol are 1.1 compared to 1 equivalent of halide.
Halide is 27.2mmols , thus phenol = 27.2x1.1 =29.92 mmols used
mass of phenol used = moles x molar mass
= 29.92mol x94g/mol
= 2.812 g
OPtion C
iii) the byproduct formed is NaI which is more covalent and is soluble in organic solvents.
Thus option e is false.
iv) the theoretical yield of the product is 27.2 mmol
mass of theoretical yield of product = mol x molar mass
= 27.2x10-3 molx 150 g/mol
= 4.08 g
% yield of product = 3.56 x100/4.08
= 87.25%
OPtion A correct