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.
