7.1 Mixtures and Solutions Flashcards
What type of composition do mixtures have
Mixtures have variable composition, 2 samples from the same solution can hold different concentrations of its components.
What type of composition do pure substances have
Pure substance have fixed composition, any sample of pure water contains 2 hydrogen atoms per oxygen atoms, the ration is fixed.
What type of physical properties do pure substances have
Has constant physical properties. (Color, odor, density, melting point, boiling point, etc.)
What type of Physical properties do mixtures have
Has variable physical properties.
What type of chemical properties do pure substances have
Has constant chemical properties. (reactivity, toxicity, kindling temperature, etc.)
What type of chemical properties do mixtures have
Has variable chemical properties.
how can you describe pure substances
Can be described by a formula. (H2O, C12H22O11, etc.)
how can you describe mixtures
Can be described only by a recipe. (salad dressing = 3 parts oil, 1 part vinegar, etc.)
How are pure substances combined, and what is the effect on components
Are chemically combined so that individual component properties are ¨lost¨ in compounds. (CuS is neither copper in color nor yellow.)
How are mixtures combined, and what is the effect on components
Are physically combined so that individual components retain their properties. (Oil and vinegar in the dressing can be detected by eye, nose, and tongue.)
How are pure substances combined and how does that effect their separation
Are chemically combined so that components separate only on application of considerable energy. (chemical reaction)
How are mixtures combined and how does that effect their separation
Are physically combined so that components separate by low energy processes. (mechanical sorting, filtering, boiling, freezing)
What type of geneousity do pure substances
Are homogeneous and so exhibit one phase. (distinct zone with uniform properties)
What type of geneousity do mixtures
May be homogeneous (solutions) or heterogeneous (mechanical mixture). If heterogeneous, it may have several phases, like salad dressing.
What’s one way to tell if a substance is a mixture or pure substance
If a substance can be acquired in more than one form (excluding states of matter) it is probably a mixture, ink can come in various colours, viscosities, and peculiarities.
What are solutions made of
Solutions are made of a solute dissolved into a solvent
There is usually more solvent than solute
What is the most common type of solution
The most common type of solution contains a solid solute and a liquid solvent, though solutions made of every combination of states do exist.
What is an alloy
Alloys are solutions of two metals
What are amalgams
Amalgams are solutions involving mercury
What are aqueous
Aqueous solutions are solutions with the solvent as water
How does polarity affect solubility
If electrons are displaced to one part of a molecule it creates a dipole, where side is more negative and the other side is more positive. These molecules are polar, while those with evenly distributed electrons are non-polar
How does Molecular size affect solubility
when molecules are about the same size they fit in between each other better
How does temperature affect solubility
as temperature increases, solids can more easily dissolve in liquids as their is more space between molecules. meanwhile gases become less soluble in liquids, and liquids have no main pattern of either increase or decrease.
how does pressure affect solubility
Pressure allows gases to be dissolved in liquids more easily as it can be squeezed into the liquid more easily.
