84 Questions
What is the main principle behind the solubility of a substance in a solvent?
Like dissolves like
What happens to the structural units of a substance when it dissolves?
The structural units (ions or molecules) become separated from each other
What type of forces must be overcome during dissolution, melting, and boiling?
Interionic or intermolecular forces
Where does the necessary energy come from during dissolution?
The energy required to break the bonds between solute particles is supplied by the formation of bonds between the solute particles and the solvent molecules
What type of solvents are able to dissolve ionic compounds appreciably?
Water or other highly polar solvents
What is the characteristic of a polar molecule?
A polar molecule has a positive end and a negative end
What is the role of solvent molecules during dissolution?
The spaces in between the structural units become occupied by solvent molecules
What replaces the old attractive forces between solute particles during dissolution?
New bonds between the solute particles and the solvent molecules
What type of solvents are most closely related in structure to ionic compounds?
Highly polar solvents
What is the principle that determines the solubility of a substance in a solvent?
Like dissolves like
What type of compounds tend to resemble hydrocarbons more than water?
Nonpolar compounds
What is the result of the reaction of a phenol with NaHCO3?
Formation of a water-soluble sodium salt
What type of compounds with shorter carbon chains and oxygen or nitrogen are likely to be soluble in water?
Compounds with shorter carbon chains and oxygen or nitrogen
What does the presence of an amino group in a compound indicate in the solubility test with dilute acids?
The compound is water-soluble
What type of compounds dissolve in or react with concentrated H2SO4?
Compounds with carbon-carbon pi bonds, oxygen, nitrogen, or sulfur
What type of bonding between solute and solvent increases solubility?
Hydrogen bonding
What is the outcome of the dissolution of a carboxylic acid of high molar mass in an aqueous medium?
Evolution of CO2
How does branching of the alkyl chain in a compound affect its solubility in water?
It increases solubility in water
What is the term used for substances that react with concentrated H2SO4 to form a soluble salt?
Neutral compounds
For what type of compounds do exceptions occur regarding similar polarity within the same family?
Larger compounds
In what form are ionic compounds water soluble?
In their ionic form
What is the expected observation when a compound dissolves in concentrated H2SO4?
Formation of a dark solution or the formation of a precipitate
What is the expected result when a carboxylic acid reacts with a base in dissolution?
Effervescence resulting from the decomposition of carbonic acid to carbon dioxide and water
How do organic compounds become ions?
Through acid-base reactions
What is the outcome of the reaction of an alkene with concentrated H2SO4?
Formation of an alkyl hydrogen sulfate
What three factors determine the solubility of organic compounds in water?
Molar mass, presence of polar groups, and ability to form hydrogen bonds
How does concentrated H2SO4 affect oxygen-containing compounds?
Protonates them to form a soluble oxonium salt
Why do carboxylic acids and phenols dissolve in sodium hydroxide?
Due to formation of sodium salts
What can the solubility of compounds in aqueous sodium bicarbonate indicate?
Presence of carboxylic acid groups
What is indicated by the solubility of an unknown compound in dilute HCl?
Presence of an amino group
What type of solvents do ionic compounds dissolve in?
Solvents with high dielectric constants
What are ions surrounded by in solution?
A cluster of solvent molecules
What type of bonds are formed between ions and solvent molecules?
Ion-dipole bonds
What is the most important principle for techniques like crystallization, extraction, and chromatography in organic chemistry?
Solubility
How is the solubility of non-ionic compounds determined?
By their polarity
In what type of solvents do non-polar or weakly polar compounds dissolve?
Non-polar or weakly polar solvents
How is the extent to which a substance dissolves in a solvent expressed?
In grams per liter or milligrams per milliliter
Why is water a superior solvent for ionic substances?
High dielectric constant, polarity, and ability to form hydrogen bonds
What happens when two liquids are miscible?
They mix homogeneously in all proportions
What determines the polarity of a compound?
Presence of polar bonds and the shape of the molecule
What is the main principle behind the solubility of a substance in a solvent?
Like dissolves like; a substance is most soluble in a solvent to which it is most closely related in structure
What does the presence of an amino group in a compound indicate in the solubility test with dilute acids?
The compound is likely to be soluble in water
What type of compounds with shorter carbon chains and oxygen or nitrogen are likely to be soluble in water?
Polar compounds
What determines the polarity of a compound?
The presence of functional groups and their arrangement
How does branching of the alkyl chain in a compound affect its solubility in water?
Branching decreases solubility in water
What type of compounds tend to resemble hydrocarbons more than water?
Nonpolar compounds
What type of bonding between solute and solvent increases solubility?
Hydrogen bonding
What replaces the old attractive forces between solute particles during dissolution?
New attractive forces with solvent molecules
Why is water a superior solvent for ionic substances?
Water can form hydrogen bonds with ionic substances
What happens to the structural units of a substance when it dissolves?
They disintegrate into individual atoms or ions
What is the expected result when a carboxylic acid reacts with a base in dissolution?
Evolution of CO2
How does concentrated H2SO4 affect oxygen-containing compounds?
Protonates to form a soluble oxonium salt
What is indicated by the solubility of an unknown compound in dilute HCl?
Presence of an amino group
What type of compounds dissolve in or react with concentrated H2SO4?
Neutral compounds
How does branching of the alkyl chain in a compound affect its solubility in water?
Decreases solubility due to decreased hydrogen bonding
What replaces the old attractive forces between solute particles during dissolution?
Formation of hydrogen bonds with solvent molecules
What is the role of solvent molecules during dissolution?
Formation of new attractive forces between solute particles
What determines the polarity of a compound?
Electronegativity difference between atoms within the molecule
What happens when two liquids are miscible?
They mix uniformly to form a single phase
How are ions surrounded by in solution?
By hydration shells formed by solvent molecules
Which type of compounds are generally insoluble in water?
Alkanes and alkenes
What type of compounds are likely to be soluble in water?
Compounds with shorter carbon chains and oxygen or nitrogen functional groups
What is the main principle behind the solubility of a substance in a solvent?
Intermolecular forces
What type of bonding between solute and solvent increases solubility?
Hydrogen bonding
What happens to the structural units of a substance when it dissolves?
They remain unchanged
In what type of solvents do non-polar or weakly polar compounds dissolve?
Nonpolar solvents
What is the key factor that determines the solubility of non-ionic solutes?
Polarity of the solvent
In which type of solvent do non-polar or weakly polar compounds dissolve?
Non-polar solvents
What is the main principle behind techniques like crystallization, extraction, and chromatography in organic chemistry?
Solubility
What type of compounds are nonpolar in nature according to the given guidelines for predicting polarity and solubility?
Hydrocarbons
What do miscible liquids do when mixed with each other?
Mix homogeneously
What is the solubility relationship between water and diethyl ether?
Immiscible
What type of compounds are determined as soluble based on their polarity?
Compounds with halogen atoms
What is the extent to which a substance can dissolve in a solvent called?
Solubility
What describes the solubility relationships between liquids?
Miscibility
What do polar compounds dissolve in?
Highly polar solvents
Which type of compounds tend to resemble hydrocarbons more than water?
Compounds with long alkyl chains
What is the primary reason for the high solubility of ionic compounds in water?
Strong attraction between ions and polar water molecules
Which type of compounds are generally insoluble in water?
Alkanes, alkenes, alkynes, and alkyl halides
What type of compounds are generally soluble in water?
Compounds with four or fewer carbons and oxygen or nitrogen functional groups
What is the primary factor that increases solubility for compounds of similar polarity in water?
Formation of hydrogen bonds with water
What is the primary reason for the solubility of carboxylic acids and phenols in sodium hydroxide?
Formation of their water-soluble salts
What type of functional groups do water-soluble organic compounds typically have?
Alcohols or carboxylic acids
What is the main mechanism through which organic compounds become ions for increased solubility in water?
Proton transfer through acid-base reactions
Study Notes
-
Ionic compounds dissolve in solvents with high dielectric constants, such as water, due to its polarity and ability to form hydrogen bonds.
-
In solution, ions are surrounded by a cluster of solvent molecules and are referred to as solvated or hydrated.
-
Electrostatic attraction between ions and solvent molecules results in the formation of ion-dipole bonds.
-
Solubility is the most important principle for techniques like crystallization, extraction, and chromatography in organic chemistry.
-
Non-ionic compounds' solubility is determined by their polarity.
-
Non-polar or weakly polar compounds dissolve in non-polar or weakly polar solvents, while highly polar compounds dissolve in highly polar solvents.
-
Solubility is the extent to which a substance dissolves in a solvent and is expressed in grams per liter or milligrams per milliliter.
-
Water is a superior solvent for ionic substances due to its high dielectric constant, polarity, and ability to form hydrogen bonds.
-
Two liquids that are miscible will mix homogeneously in all proportions, while immiscible liquids will not mix homogeneously and will form separate layers.
-
The polarity of a compound is determined by the presence of polar bonds and the shape of the molecule.
-
Hydrocarbons are nonpolar, while compounds with electronegative elements like oxygen or nitrogen are polar.
-
Halogen atoms do not significantly alter the polarity of an organic compound, making them only slightly polar.
-
The polarity of certain compounds is more similar to that of nonpolar hydrocarbons than to water's highly polar nature.
-
Adding carbon atoms to a compound's chain within the same family decreases its polarity, making it more hydrocarbon-like.
-
Compounds with four or fewer carbons and oxygen or nitrogen functional groups are generally soluble in water.
-
Hydrogen bonding between solute and solvent can increase solubility for compounds of similar polarity.
-
Branching of the alkyl chain in a compound lowers intermolecular forces, leading to greater solubility in water for branched compounds.
-
Most compounds within the same family have similar polarity, but exceptions may occur due to significant size differences.
-
Ionic compounds, including some organic ones, are highly soluble in water due to the strong attraction between ions and polar water molecules.
-
Organic compounds become ions primarily through acid-base reactions, such as carboxylic acids forming water-soluble salts.
-
Water-soluble organic compounds typically have a polar group that forms a hydrogen bond with water, such as alcohols or carboxylic acids.
-
Carboxylic acids and phenols dissolve in sodium hydroxide due to the formation of their water-soluble sodium salts.
-
In aqueous sodium bicarbonate, carboxylic acids dissolve due to forming their water-soluble sodium salts, while phenols usually do not deprotonate in this medium.
-
Alkanes, alkenes, alkynes, and alkyl halides are generally insoluble in water.
Test your knowledge on predicting the polarity and solubility of organic compounds based on their structure and composition. This quiz covers guidelines for comparing the polarities of hydrocarbons and water, as well as the impact of chain length on polarity.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
