Test 1 (1 - 12) Flashcards
What is a solution?
A solution is a mixture in which one substance called the solute is uniformly dispersed in another substance called the solvent. Almost always a liquid which is called homogenous.
What is Diffusion?
process where particles of liquid, gases, or solid mix as the result of their spontaneous movement caused by thermal agitation and in dissolved substances move from a region of higher to one lower concentration.
Solvent classification, what is it divided into?
Examples of organic solvents
- Hexane
- Benzene
- Methanol
- Ethanol
- Acetone
- chloroform
Examples of inorganic solvents
- Water
- Liquid ammonia
- Hydrogen fluoride (HF)
- Sulphuric acid (H2SO4)
What is a protic solvent? Examples
Protic solvent: Contain in their structure a labile hydrogen atom which can form a hydrogen bond or can be donated to other reagents present in the solution
Examples:
- Water
- Methanol
- Acetic acid
- Isopropanol
What is an aprotic solvent? Examples
Aprotic solvents: Can not donate a hydrogen atom
Examples
- Acetone
- Chloroform
- Dimethylformamide
What is a polar solvent? Examples
Chemical compounds with large dipole moments, they contain bonds between atoms with very different electronegativities, such as oxygen and hydrogen
Examples
- Water
- Ethanol
- Acetone
- Isopropanol
- Dimethylformamide
What are non-polar solvents? Examples
Chemical compounds with small or zero dipole moments, they contain bonds between atoms with similar electronegativities, such as carbon and hydrogen
Examples
- Hexane
- Benzene
- Chloroform
Water as a protonic and polar solvent
It is good at dissolving other protic and polar molecules
Water has an electrical dipole moment.
What is the rule for dissolving substances with each other?
Like dissolves like, because there has to be an attraction between the solute and solvent particles
polar + polar
non polar + non polar
What is solvation?
Solvation - is the process of attraction and association of molecules of a solvent with molecules of a solute.
What is hydration?
Hydration – is the process of attraction and association of molecules of a water with molecules of a solute.
Mixture classification
What is a true solution? And its qualities
The particles of solute and particles of the solvent
have similar size → below 1 nm of diameter
Its particles don’t settle
Its particles can’t be separated by filters or semipermeable membranes
What is a suspension? And its qualities
Heterogeneous mixture –> The particles of the solute are large (diameter of 1um), they can often be seen by the naked eye. The particles precipitate if the suspension is allowed to stand undisturbed
Its particles can’t be separated by semipermeable membranes, but they can be by filters
What is a colloid? And its qualities
a solution that has particles ranging between 1 and 1000 nm in diameter, evenly distributed throughout the solution.
Its particles don’t settle
Its particles can’t be separated by filters, but they can be by semipermeable membranes
Colloid classification
Sol - colloidal suspension with solid particles in a liquid.
Emulsion - two liquids.
Foam - many gas particles are trapped in a liquid or solid.
Aerosol - small particles of liquid or solid dispersed in a gas.
Gel – liquid particles trapped in a solid.
What are liophilic colloids?
Strong affinity to dispersing medium
Liophilic (hydrophilic) colloid,Solid particles are solvated (hydrated)
What are liophobic colloids?
Weak affinity to dispersing medium
Liophobic (hydrophobic) colloid
Solid particles are not solvated, they are stabilized by electric charge on their surface