12 The table lists a few properties of substances: 1. Density 2. Color 3. Lue To Apply the prices of verification ina mixture, which property of the substances should vary?
Answers
Explanation:
Mixtures and Compounds
Mixtures are heterogeneous forms of matter. Mixtures are composed of variable proportions of molecules and atoms.
Compounds are homogeneous forms of matter. Their constituent elements (atoms and/or ions) are always present in fixed proportions (1:1 depicted here).
Examples of mixtures:
soil
ocean water and other solutions
air
the cytosol of a cell
Examples of compounds:
water (H2O)
table salt (NaCl)
sucrose (table sugar, C12H22O11)
Properties of Mixtures
The composition of a mixture is variable.
Each of its components retains its characteristic properties.
Its components are easily separated.
Properties of Compounds
The relative proportions of the elements in a compound are fixed.
The components of a compound do not retain their individual properties. Both sodium and chlorine are poisonous; their compound, table salt (NaCl) is absolutely essential to life.
It takes large inputs of energy to separate the components of a compound.
Separating the Components of a Mixture
Most laboratory work in biology requires the use of techniques to separate the components of mixtures. This is done by exploiting some property that distinguishes the components, such as their relative
size
density
solubility
electrical charge
Dialysis
Dialysis is the separation of small solute molecules or ions (e.g., glucose, Na+, Cl-) from macromolecules (e.g., starch) by virtue of their differing rates of diffusion through a differentially permeable membrane.
An example:
Cellophane is perforated with tiny pores that permit ions and small molecules to pass through but exclude molecules with molecular weights greater than about 12,000. If we fill a piece of cellophane tubing with a mixture of starch and sugar and place it in pure water, the sugar molecules (red dots) will diffuse out into the water until equilibrium is reached; that is, until their concentration is equal on both sides of the membrane. Because of their large size, all the starch (blue disks) will be retained within the tubing.
Answer:
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