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“When the well is dry, we know the worth of water” Benjamin Franklin Mineral water (integrated mathematic-chemistry lesson) The aim of the lesson: to get acquainted with variety of mineral waters of Lithuania. The goals of the lesson: To explore general mineralization of mineral water. To measure qualitative components of mineral water “Vytautas”. To learn to solve integrated mathematicschemistry tasks. The classification of mineral water Mineral waters wich have very few minerals: the concentration of minerals ≤ 50mg/l. Examples: “Neptūnas” “Rytas” “Perrier” “Vittel” Mineral waters wich have few minerals: the concentration of minerals ≤ 500mg/l. Mineral waters wich have a lot of minerals: the concentration of minerals > 1500mg/l. Examples: “Rasa” “Vytautas” “Naleczovanka” “Augustovianka” 0 605 877 Naleczovianka 403 Augustovianka 2745 Fuldataler 349 Perrier 500 Vittel 4000 Vichy Celestines Neptūnas 2000 Tiche 3000 ruskininkų Rasa 1000 Aqville Birutė 8000 Vytautas Total Dissolved Solids (TDS) mg/l 7200 7000 6000 5000 3378 2515 2017 1378 713 Answers of group chemistry tasks: Group 1 : Ag+(aq) + Cl-(aq) → AgCl(s) Group 2 : Ca2+(aq) + CO32-(aq) → CaCO3(s) Group 3 : Ba2+(aq) + SO42-(aq) → BaSO4(s) Group 4 : H+(aq) + HCO3-(aq) → CO2(g) + H2O(l) n 1. C = V 534 mg/l · 1l = 534 mg 534 = 0,534 g 1000 n(Ca2+ )= 0,534g = 0,013mol 40g / m ol 0,013 mol 2 0,013 mol / l C= 2l 2. Ca2+(aq) + Na2CO3(aq) → CaCO3(s) + 2Na+(aq) n(Ca2+) = 0,013 mol n(Na2CO3) = 0,013 mol n C= V 0,013m ol V= 0,5m ol/ l = 0,026l 3. “Vytautas” 3437mg/l · 1l = 3437mg 3437 mg = = 3,437g 1000 3,437g w(Cl ) = · 100% = 47,98% 7,165g m(Cl-) “Perrier” 21,5mg/l · 1l = 21,5mg 21,5mg m(Cl ) = 1000 0,0215g w(Cl ) = · 100% = 3,56% 0,6046g 1. Let us assume, that: x is the number of small bottles (0,5l), y is the number of large bottles (1,5l). Make an equation system: x + y = 36 0,5x + 1,5y = 42 x = 36 – y 0,5x + 1,5y = 42 0,5 · (36 – y) + 1,5y = 42 18 – 0,5y + 1,5y = 42 y = 42 – 18 y = 24 x = 36 – 24 = 12 The answer: there are 12 small bottles (0,5l) and 24 large bottles (1,5l) 2. Let us assume, that: Let us assume, that: x is the number of small bottles (0,5l) of mineral water “Vytautas” y is the number of small bottles (0,5l) of mineral water “Rasa” t is the number of large bottles (1,5l) of mineral water “Tiche” z is the number of large bottles (1,5l) of mineral water “Vytautas” Make an equation system: Make an equation system: x + y = 12 x=y+2 y + 2 + y = 12 2y = 12 – 2 2y = 10 / ÷2 y=5 x=5+2=7 t + z = 24 t = 3z 3z + z = 24 4z = 24 / ÷4 z=6 t = 3 · 6 = 18 2. Count the praise: 5 · 1,39 + 7 · 1,49 + 6 · 2,29 + 18 · 2,09 = 68,74 The answer: 68,74 Litas 3. Convert to Euros: 68,74 ÷ 3,4528 ≈ 19,9 Convert to Zlotys: 68,74 ÷ 0,81765 ≈ 84,07 Conclusion Mineral water is underwater which contains minerals and has curative features; 1 litre of mineral water should contain not less than 1gr of minerals; The composition of salts in mineral water should be constant (stable); Ionic composition of mineral water and the concentration of ions are indicated on the bottle sticker (label).