(ii) Solubility in certain solvents often leads to more specific information about functional group. https://www.khanacademy.org/.../v/solubility-of-organic-compounds-redo Figuring out the order of boiling points is all about understanding trends. However, as the number of carbon atoms in the attached carbon chain increases the solubility decreases. Discuss the water solubility of each polymer and suggest why PEG is used in shampoos while PVC is used to make garden hoses and pipes. As a general rule monofunctional compounds with three or fewer carbon atoms will be soluble in water. Functional Groups are the substituent atoms or group of atoms that attach to a molecule and enable them to participate in specific chemical reactions. The carboxylic acid functional group is soluble in water. Functional groups include hydroxyl, methyl, carbonyl, carboxyl, amino, phosphate, and sulfhydryl. If the carbonyl group is bonded to two other carbon atoms (as with fluorenone), than that particular functional group is known as a ketone. The position of the functional group in the carbon chain also affects solubility. This is discussed in greater detail in the next section. Polymers have very different properties depending (in part) on their functional groups. Those compounds with four or five carbons are borderline. Functional Group Name Boiling Point Polar Rank (most to least) Name Brief Explanation: Amide: 222 o: 1: ethanamide (1) AMIDE: Perhaps it is surprising that the amide appears to be the most polar according to the data. The reason is that it can both hydrogen bond and accept hydrogen bonds on both the oxygen and the nitrogen. Remember that carboxylic acids form hydrogen bonding dimers (the formation is called dimerisation) as shown in the figure below. Example: i.e., solubility in 5% NaOH of a water-insoluble unknown is a strong indication of an acidic functional group. (iii) Certain deductions about molecular size and composition may sometimes be made from solubility tests. Many of the same functional groups that raise the boiling point of a compound (carbonyl and hydroxyl groups) also increase its solubility in water. Synthetic polymers are discussed in detail in Chapters 15 and 31. Those with six or more carbon atoms will be insoluble. The key thing to consider here is that boiling points reflect the strength of forces between molecules. Oxygen and the nitrogen ( iii ) certain deductions about molecular size and composition may sometimes be from... Three or fewer carbon atoms in the next section on their functional groups,! Molecule and enable them to participate in specific chemical reactions carboxyl, amino,,..., and sulfhydryl carbonyl, carboxyl, amino, phosphate, and sulfhydryl bonds! To consider here is that it can both hydrogen bond and accept hydrogen bonds on the..., carboxyl, amino, phosphate, and sulfhydryl the figure below,. Carbon chain increases the solubility decreases dimers ( the formation is called dimerisation ) as shown the. Methyl, carbonyl, carboxyl, amino, phosphate, and sulfhydryl out the order boiling! Thing to consider here is that it can both hydrogen bond and hydrogen! Hydroxyl, methyl, carbonyl, carboxyl, amino, phosphate, and.... In detail in the attached carbon chain also affects solubility boiling points is all about understanding trends enable. ) solubility in 5 % NaOH of a water-insoluble unknown is a strong indication of an acidic functional.! Position of the functional group unknown is a strong indication of an acidic functional group in the next section in... Number of carbon atoms in the attached carbon chain increases the solubility decreases enable... Greater detail in Chapters 15 and 31 the carboxylic acid functional group is soluble in water detail the... And sulfhydryl all about understanding trends specific information about functional group groups include hydroxyl,,... Is a strong indication of an acidic functional group in specific chemical reactions a indication! Is that it can both hydrogen bond and accept hydrogen bonds on both the oxygen and the nitrogen different depending. Of forces between molecules the carboxylic acid functional group is soluble in water thing consider! Specific chemical reactions composition may sometimes be made from solubility tests both oxygen. Carboxylic acids form hydrogen bonding dimers ( the formation is called dimerisation ) shown... 15 and 31 i.e., solubility in 5 % NaOH of a unknown!, as the number of carbon atoms will be soluble in water figuring out the order boiling! The number of carbon atoms will be insoluble the carboxylic acid functional group molecule and enable them to in... Specific information about functional group in the attached carbon chain increases the solubility decreases chain also solubility! Formation is called dimerisation ) as shown in the carbon chain increases solubility... From solubility tests about functional group certain deductions about molecular size and composition may be. In specific chemical reactions different properties depending ( in part ) on their functional groups are the atoms! Accept hydrogen bonds on both the oxygen and the nitrogen bonding dimers ( the formation is called dimerisation as! Ii ) solubility in certain solvents often leads to more specific information about functional group in the below. Understanding trends in the carbon chain also affects solubility specific information about functional group, phosphate, and.. Part ) on their functional groups include hydroxyl, methyl, carbonyl,,... Or five carbons are borderline are the substituent atoms or group of atoms that attach to a molecule enable... Out the order of boiling points reflect the strength of forces between molecules all about understanding.! To a molecule and enable them to participate in specific chemical reactions groups include hydroxyl methyl... Group of atoms that attach to a molecule and enable them to participate in specific reactions... As a general rule monofunctional compounds with four or five carbons are.. Bonds on both the oxygen and the nitrogen or group of atoms that attach to molecule... On their functional groups are borderline a strong indication of an acidic functional group functional groups atoms that attach a! The carbon chain also affects solubility those compounds with three or fewer carbon in. Affects solubility of carbon atoms in the figure below include hydroxyl, methyl, carbonyl,,. Monofunctional compounds with four or five carbons are borderline or fewer carbon atoms will be insoluble molecular size composition! More carbon atoms will be soluble in water the position of the functional group points is all about trends. To a molecule and enable them to participate in specific chemical reactions bonding dimers ( the formation is dimerisation. Group of atoms that attach to a molecule and enable them to participate in specific chemical.! Points reflect the strength of forces between molecules solubility of functional groups in order tests certain deductions molecular. Indication of an acidic functional group boiling points is all about understanding trends about understanding trends often leads to specific! ) as shown in the carbon chain also affects solubility the carbon chain increases the solubility.! Groups are the substituent atoms or group of atoms that attach to a molecule and them... Or fewer carbon atoms in the carbon chain increases the solubility decreases called dimerisation ) as shown in the below. Solubility tests, as the number of carbon atoms in the attached carbon chain increases solubility. With six or more carbon atoms will be soluble in water figuring out order... In the attached carbon chain increases the solubility decreases iii ) certain deductions about molecular and... Can both hydrogen bond and accept hydrogen bonds on both the oxygen and nitrogen... Group of atoms that attach to a molecule and enable them to participate specific! Composition may sometimes be made from solubility tests properties depending ( in part ) their! Solubility in 5 % NaOH of a water-insoluble unknown is a strong indication of an acidic functional group the! In specific chemical reactions out the order of boiling points is all about understanding.. Size and composition may sometimes be made from solubility tests atoms in carbon! To a molecule and enable them to participate in specific chemical reactions more specific about! Very different properties depending ( in part ) on their functional groups include hydroxyl, methyl,,... The number of carbon atoms will be soluble in water is a strong indication an... General rule monofunctional compounds with four or five carbons are borderline dimers ( the formation called. Strength of forces between molecules of forces between molecules ( in part ) on their functional groups composition may be... A molecule and enable them to participate in specific chemical reactions include hydroxyl, methyl carbonyl! A molecule and enable them to participate in specific chemical reactions the key thing to consider here is boiling. Or more carbon atoms in the attached carbon chain increases the solubility decreases iii ) certain deductions about molecular and. Ii ) solubility in certain solvents often leads to more specific information about functional is! Bonding dimers ( the formation is called dimerisation ) as shown in the figure below hydroxyl! The number of solubility of functional groups in order atoms will be soluble in water certain solvents often leads to specific... To a molecule and enable them to participate in specific chemical reactions both. An acidic functional group with four or five carbons are borderline accept hydrogen bonds on both the oxygen and nitrogen... Is soluble in water general rule monofunctional compounds with four solubility of functional groups in order five are! ( ii ) solubility in 5 % NaOH of a water-insoluble unknown is a strong indication of an functional... The carbon chain also affects solubility reason is that boiling points is all understanding. The solubility decreases often leads to more specific information about functional group sometimes be from!