how to apply the rules of writing equations of chemical reactions;
You will learn
what a hydroxide is;
to name hydroxides based on their formulas;
to list and describe methods for the preparation of hydroxides and write the corresponding equations of reactions;
to give examples of metals and metals oxides reacting with water;
to identify products of reactions of active metals with water;
to give examples of acid‑base indicators and to determine their color in water and in bases.
R1KaEJFD2Yt6h
Hydroxides – structure
HydroxideshydroxideHydroxides are chemical compounds with a constant state of aggregation, made of metal cations and hydroxide anions. These ions are attracted by the action of electrostatic forces, creating crystal structurecrystal structurecrystal structure.
RvOMUiSq8vd93
The valency of the hydroxyl ions always equals I.
RqM7ABZDvkbqS
The general formula of monovalent metal hydroxides:
RlojBTteayI28
The general formula of metal hydroxides:
R17KUT9akE9hf
R54EHjeUCLHiI
Rpt7Xev9PAQlo
Hydroxide names are created by adding to the name of the element that forms the compound the word “hydroxide”:
RvxvZzMv8ivKf
RGIGwYzth0ykU
If the metal forms two hydroxides, the Roman numeral in parentheses is added to the name, indicating the valency of the metal, for example:
R1H9zyP1JPb5i
If the metal forms one hydroxide, the valency of the metal in the name is omitted:
RRZCQRH5UK36f
R13rW4kpjs46s
Indicators
The fact that the studied compounds have different properties can be seen using substances called indicators. Their action under the influence of other substances depends on the fact that they change the color in an easy to observe way. This allows us to determine whether the sample is the substance interesting for us.
In everyday life we also find indicators. Tea, to which we add lemon juice, changes its color to lighter. Similarly, when we add lemon juice (citric acid) or vinegar (acetic acid) to beetroot juice, the dye in this juice under the influence of acids will take on an intense red color.
An indicator changing colour in water solutions, to which we add metals and metal oxides (with the creation of a new chemical compound – hydroxide) is, among others, decoction of red cabbage.
Task 1
Formulate a research question and hypothesis before watching the video ‘Observation of colour indicators in bases’. Write down your observations and concluding remarks.
R130jvMR2LAJF
R2HyupUhHj8wz
R13pIOz4tcauz
An indicator or an indicating dye is a substance with which we can detect another substance, e.g. as a result of a change in color.
Rn3qFCMnZRsSu
R1FDb4jCvEe0e
Exercise 1
Summary
Hydroxides are chemical compounds made of metal cations and hydroxide anions whose general formula is .
Hydroxides are obtained as an effect of the reaction of active metal oxides (basic oxides) with water and of some metals with water.
Solutions of hydroxides that are easily soluble in water (all hydroxides of metals from the 1st group of the periodic table and selected metals from the 2nd group) are traditionally called bases.
R18Tcfx8PL0qw1
Keywords
crystal web, hydroxide
Glossary
crystal structure
crystal structure
RM6dPFcZgFzKh
sieć krystaliczna – to szczególne ułożenie atomów lub cząsteczek w ciele stałym. Charakteryzuje się uporządkowaniem dalekiego zasięgu oraz symetrią.
hydroxide
hydroxide
R1d3pqZvTtmU5
wodorotlenek – związek chemiczny zbudowany z kationów metalu i anionów wodorotlenkowych