Water of crystallization Beāte Laķe Teacher of biology Riga Secondary Night (Shift) School No.14 H O crystals In rocks water of crystallization can be found 20 times more than.

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Transcript Water of crystallization Beāte Laķe Teacher of biology Riga Secondary Night (Shift) School No.14 H O crystals In rocks water of crystallization can be found 20 times more than.

Water of crystallization

Beāte Laķe Teacher of biology

Riga Secondary Night (Shift) School No.14

H

O crystals

In rocks water of crystallization can be found

times more than in oceans and sees

Crystals that have locked up water in themselves for millions of years..

Quartz

While distributing water from crystals we can learn about the development of the Earth

Crystals of gympsum

Stalactites made by water in Slovenia

Crystalhydrates Crystal hydrate is a hard crystal matter that has chemicly joined with water -water of crystallization (e.g., AlCl 3 · 6H 2 O , BeCl 3 · 4H 2 O etc.). While heating crystalhydrates, water of crystallization can fully or partly be saparated.

Crystalhydtare No-water substance

Water of crystallization

5H 2 O CuSO 4 · 5H 2 O

CuSO 4

No-water CuSO 4 when added water – heat is caused to spread – So a chemical reaction is happening.

Different colours of crystalhydrates: Cu(NO 3 ) 2 ·6H 2 O blue.

CoCl 2 ·6H 2 O red CuSO 4 ·5H 2 O blue. CuSO 4 ·1H 2 O whites.

CuSO 4 ·5H2O

[Cu(4H 2 O)]SO 4.

H 2 O- formula of complex combination

Pink colour of Mn(II) crystalhydrates, e.g.,

Mn(NO 3 ) 2 ·6H 2

O and MnCl

2 ·2H 2 O MnCl 2 ·2H 2 O Mn(NO 3 ) 2 ·6H 2 O

Ni(NO 3 ) 2 x6H 2 O.

Gympsum

CaSO 4 ·2H 2 O

Crystals of gypsum can reach up to 15 m

Heated

CaSO 4 ·½H 2 O

is used in medicine, art, construction.

Exercise

• 74,25 g zinc nitrate’s crystalhydrate consists of 27,00 g of water. Calculate the formula of the crystalhydrate!

Clue a) A formula of the unknown crystalhydrate is written as Zn(NO 3 ) 2 ·xH 2 O, where x shows, how many moles of water contains the particular crystalhydrate to each mole of no-water salt.

• • b) Calculate the no-water salt’s mass in the crystalhydrate.

m(Zn(NO 3 ) 2 ) = m(Zn(NO 3 ) 2 ·nH 2 O) – m(H 2 O) = 74,25 – 27,00 = 47,25 g

Further… c) Calculate the no-water salt’s and water’s amount in the crystalhydrate.

• • Further..

d) To form the formula the crystalhydrate, calculate how many moles of water are joined with one mole of no-water salt. With water.

0,25 moles Zn(NO 3 ) 2 are joined 1,5 moles of • With 1 water mole Zn(NO e) Calculate x.

3 ) 2 are joined x moles of

Answer.

• f) Write the formula of the crystalhydrate.

Zn(NO 3 ) 2 ·6H 2 O

• • • • • •

Bibliography

Ahmetovs N., “Neorganiskā ķīmija” – R: Zvaigzne, 1978.

Feldmanis F., Rudzītis G.,“Neorganiskā ķīmija” – R: Zvaigzne, 1981.

Valdis Segliņš Minerāli un ieži.-RaKa, 2007.g.

Water of crystallization Beāte Laķe Teacher of biology Riga Secondary Night (Shift) School No.14 H O crystals In rocks water of crystallization can be found 20 times more than.

Transcript Water of crystallization Beāte Laķe Teacher of biology Riga Secondary Night (Shift) School No.14 H O crystals In rocks water of crystallization can be found 20 times more than.