Digital Magazine Walk through Science Digital Magazine 1st issue WtS | Page 21

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It involves pouring oxidized water into the Erlenmeyer flask. Then we add 1tablespoon of
dishwashing liquid and food dye - if we have a liquid dye, we use about 10 drops. If we have it
in powder we disintegrate in the water needed to dissolve the yeast. We mix the mixture
gently. In a separate container, we mix 3 tablespoons of warm water with 1 tablespoon of
yeast and possible dye. We quickly pour the yeast into the bottle with oxidized water and
admire the effect.
Second chemical experience
By Dominika Szyda, Poland
In the second chemical experiment we performed a qualitative analysis in which metal ions
were detected.
The analysis consists of the precipitation of precipitates and the separation of cations or ani-
ons of subsequent groups with the use of group reagents. The individual components of the
mixture are then identified using selective or specific reagents. This is the so-called systemat-
ic analysis. We have detected copper, magnesium and sodium.
Copper
a) Reaction copper with ammonia
Influence of ammonia caused that, copper (II) cations form a gelatinous blue hydroxyl
precipitate, soluble in an excess of the reagent in the color of sapphire.
b) Reaction copper with sodium hydroxide
A blue precipitate forms, insoluble in the excess of the reagent.
Magnesium
a) Reaction of magnesium with sodium hydroxide
Strong bases sediment a white, gelatinous magnesium hydroxide precipitate insoluble
in the excess of the reagent from solutions containing magnesium ions.
b) The reaction of magnesium with ammonia
Magnesium ions react with ammonia to form a little soluble magnesium hydroxide.
Sodium
a) Reaction of sodium with potassium hexahydroxoantimonate
In an inert or slightly bases environment, this reagent reacts with the sodium ion to form
a white, crystalline precipitate of sodium hexahydroxoantimonate.
Both of these reactions were interesting and gave us lot of
information. We learned a lot that day, but we also had a great
time. It was an unforgettable day.