Chemistry Reference
In-Depth Information
Water
●
Tests to show the presence of water using cobalt
chloride paper and anhydrous copper(ii)
ii
) sulfate.
●
Tests to show that water is pure: it melts at 0 °C or
boils at 100 °C.
●
Preparation of sodium sulfate-10-water by titration.
Use the same method as on p. 124, using dilute
sulfuric acid and dilute aqueous sodium hydroxide.
●
Preparation of sodium hydrogensulfate by titration.
Use the results from the previous exercise but add
double the titre of acid to the same volume of
alkali.
●
Comparison of the salts sodium sulfate and sodium
hydrogensulfate. Compare their crystal shapes.
Measure the pH of their aqueous solutions. Add
magnesium powder to both salts in solution. Add
excess dilute hydrochloric acid and barium chloride
solution to both solutions.
Hardness in water
●
Standard experiments with permanently and
temporarily hard water. Measure the number of
drops of soap solution needed to form a permanent
lather in 10 cm
3
samples of both types of hard water.
Boil both types and allow to cool. Then measure the
number of drops of soap solution needed to produce
a permanent lather in 10 cm
3
samples of the treated
samples of hard water. The study can be extended
to include the addition of sodium carbonate and
treatment with ion exchange resins.
●
Compare soap and soapless detergents. Add soap
solution dropwise with shaking to samples of hard
and soft water. Repeat using a soapless detergent.
Concentrated sulfuric acid
●
Reactions with copper(ii)
ii
) sulfate-5-water and sugar.
●
Oxidation of metals, such as copper.
●
Make nitric acid and sulfuric acid.
Chapter 13 Inorganic carbon
chemistry
Carbonates
●
Heat a piece of calcium carbonate. Allow it to
cool and carefully add water dropwise. Then add
excess water and filter. Keep the filtrate, a solution
of calcium hydroxide. Make carbon dioxide by
adding an acid to calcium carbonate. Bubble
this gas through the previously prepared calcium
hydroxide solution until no further change is
observed. Boil the resulting solution of calcium
hydrogencarbonate.
●
Action of heat, if any, on sodium, zinc and copper
carbonates.
●
Reaction of acids with a selection of carbonates.
●
Formation of insoluble carbonates by precipitation.
Add aqueous sodium carbonate to solutions of
copper sulfate, calcium chloride and nickel sulfate.
Chapter 12 Sulfur
Sulfur and sulfur compounds
●
Burn sulfur in air or oxygen. Show that an acidic
gas is formed.
●
Formation of metal sulfides. Demonstrate the
reactions of sulfur with iron, zinc and magnesium -
care is needed.
●
Preparation of sulfur trioxide. Pass dry oxygen
and sulfur dioxide over heated platinised mineral
wool. Collect sulfur trioxide as a solid in a cooled
receiver.
●
Reaction of sulfur trioxide with water - care is
needed. Test the solution to show that it is acidic
(using both universal indicator and magnesium
powder), and that it contains sulfate ions (by
adding acidified barium chloride solution).
Carbon dioxide
●
Laboratory preparation of carbon dioxide and its
properties (Figure 13.16, p. 214).
●
Demonstrate that carbon and carbon-containing
compounds form carbon dioxide on combustion.
Burn a variety of materials and test for carbon
dioxide with limewater. Suitable materials are a
candle, wood shavings, charcoal, paraffin etc.
Dilute sulfuric acid
●
Reaction with magnesium and zinc.
R
●
Reaction with bases - CuO and NaOH(
aq
).
●
Reaction with carbonates - NiCO
3
, CoCO
3
and
Na
2
CO
3
(
aq
).
●
Precipitation of insoluble sulfates of barium, lead
and calcium.
