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Basic Chemistry III. Vladimíra Kvasnicová. Add formulas:. sodium sulfite potassium phosphate ammonium hydrogen phosphate lithium dihydrogen phosphate calcium hydrogen carbonate silver sulfide zinc sulfate potassium permanganate sodium hypobromite barium nitrate hydrargyric chloride.
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Basic Chemistry III Vladimíra Kvasnicová
Add formulas: • sodium sulfite • potassium phosphate • ammonium hydrogen phosphate • lithium dihydrogen phosphate • calcium hydrogen carbonate • silver sulfide • zinc sulfate • potassium permanganate • sodium hypobromite • barium nitrate • hydrargyric chloride
Add formulas: • sodium tetraborate decahydrate • potassium aluminium sulfate • sodium aluminium sulfate dodecahydrate • ammonium carbonate • calcium sulfate hemihydrate (hemi = ½) • zinc sulfate heptahydrate • potassium dichromate • potassium magnesium fluoride • ammonium magnesium phosphate • led(II) chloride fluoride • cupric biscarbonate difluoride (bis = twice)
Important terms: • reactants / products • stoichiometric coefficients • substance amount • relative atomic / molecular mass • molar mass • density • concentration (molar, percent)
molar concentration (= molarity)M = mol/1000 mL 1M solution 1 mol of a solute is found in 1000 mL (= 1L) of the solution 0,5M solution 0,5 mol of a solute is found in 1000 mL (= 1L) of the sol. percent concentration% = g/100g 1% solution 1 g of a solute is found in 100 g of the solution 0,5% solution 0,5 g of a solute is found in 100 g of the solution
Chemical reactionsexercises Calculate the mass of KOH and the volume of 96% H2SO4 needed for preparation of 25 g of K2SO4 Molar masses (MW): KOH 56.11 g/mol H2SO4 98.08 g/mol K2SO4 174.26 g/mol Density of 96% H2SO4: 1.8355 g/cm3 16.1 g KOH and 7.99 mL of 96% H2SO4 • write related chemical equation • balance the equation • find the stoichiometric ratios of reacting substance amounts • convert substance amounts to mass (KOH) or volume (H2SO4)
Chemical reactionsexercises 5 mL of 0,5 M KMnO4 were mixed with 25 mL of Na2SO3, the reaction processed quantitatively. Calculate concentration of Na2SO3 (both: molarity and %). KMnO4 + Na2SO3 + H2O → MnO2 + Na2SO4 + KOH n = 2 3 1 2 3 2 Molar masses (MW): Na2SO3 126 g/mol KMnO4 158 g/mol 0.15M = 1.89% Na2SO3 • balance the chemical equation • find the stoichiometric ratios of reacting substance amounts • convert substance amounts to molar and % concentrations
Chemical reactionshomework 100 g of FeS was used for the chemical reaction: FeS + HCl → FeCl2 + H2S • balance the equation • calculate what volume of HCl (36%, density = 1,18 g/ml) was needed for the reaction • calculate mass of FeCl2 prepared by the reaction Ar(Fe) = 55,8 Ar(S) = 32,1 Ar(Cl) = 35,5 Ar(H) = 1,0
Exercise Describe dissociation of the salts: KNO3→ K2CO3→ Na3PO4→ Na2HPO4→ NaH2PO4→ NH4HCO3→ What is the osmolarity of the 1M solutions?