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Water of crystallization. Beāte Laķe Teacher of biology Riga Secondary Night (Shift) School No.14. H 2 O crystals. In rocks water of crystallization can be found 20 times more than in oceans and sees. Crystals that have locked up water in themselves for millions of years.
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Water of crystallization Beāte Laķe Teacher of biology Riga Secondary Night (Shift) School No.14
In rocks water of crystallization can be found 20 times more than in oceans and sees
Crystals that have locked up water in themselves for millions of years..
While distributing water from crystals we can learn about the development of the Earth
Crystalhydrates Crystal hydrate is a hard crystal matter that has chemicly joined with water - -water of crystallization (e.g., AlCl3·6H2O, BeCl3·4H2O etc.). While heating crystalhydrates, water of crystallization can fully or partly be saparated.
No-water CuSO4 when added water– heat is caused to spread– So a chemical reaction is happening.
Different colours of crystalhydrates: Cu(NO3)2·6H2O blue. CoCl2 ·6H2O red CuSO4·5H2O blue. CuSO4·1H2O whites. CuSO4·5H2O
Pink colour of Mn(II) crystalhydrates, e.g., Mn(NO3)2·6H2O and MnCl2·2H2O MnCl2·2H2O Mn(NO3)2·6H2O
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(NO3)2·xH2O, 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(NO3)2) = m(Zn(NO3)2·nH2O) – m(H2O) = 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 0,25 moles Zn(NO3)2 are joined 1,5 moles of water. With 1 mole Zn(NO3)2 are joined x moles of water • e) Calculate x.
Answer. • f) Write the formula of the crystalhydrate. Zn(NO3)2·6H2O
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. • www.google.com • www.webelements.com • www.webminerals.com