Chemistry Reference
In-Depth Information
“Solubility”
“Acids”
qualitative analysis scheme,
Solubility product,
k
S
-Value, Buffer
ion product, pH-Value
Acid-Base Equilibrium
-Value
Solubility equilibrium
Distribution equilibrium
k
L
Concentration (mol/L),
Per cent by volume (Vol %),
Per cent by mass (%),
Solubility (g/100g)
Neutralization
H
+
(aq), OH
-
(aq),
acidic, alkaline,
indicator, pH-Value
Solubility and temperature,
Substances are not soluble,
Substances are soluble
acidic solutions,
lemon juice, vinegar
something tastes sour
Common knowledge
Common knowledge
Fig. 7.4 Terms “solubility” and “acids” in the spiral curriculum from grade 8 to 12
Reality (Original)
Conscious (Mental model)
Reality (Concrete model)
only sugar
particles
mixed with
water
particles rapidly
moving
Solution
of
Sugar
in
Water
substance, sugar,
water, sugar solution,
rock sugar crystals,
beet sugar, powdered
sugar, sweet taste, sirup,
melted sugar
particles, particle size
movement of particles,
sugar particles, water particles,
arrangement of particles,
crystal structure,
C-, H- and O-atoms in the
sugar molecule
sphere, ball, disk, cross
small and big balls,
moving balls,
red and blue color,
structural model,
packing of spheres,
molecular model
Fig. 7.5 Terms on the level of substances, mental models and concrete models
has been discussed in Chap. 6, Steinbuch's scheme [
9
] was illustrated there
(see Fig. 6.2). According to the three different levels related terms should be
differentiated: terms of the substance level, of the mental models level, and the
concrete models level. Figure
7.5
shows one example for the solution of sugar
in water and the interpretation on the basis of a particle model of matter. The terms
of one level should be connected consequently during a class discussion: sugar
