Question

Calculeaza cantitatea de substanta si masa hidrogenului care se elimina la interactiunea a 36g de apa cu a)un metal monovalent;b)un metal bivalent

Answer 1

Metal monovalent: Na
2 Na + 2 H2O --->2 NaOH + H2
la 2 * 18 g H2O........2 * 40 g NaOH........2 g H2
la 36 g H2O.......x g NaOH...........y g H2        x=80 g NaOH si y = 2 g H2
Metal divalent: Mg
Mg + 2 H2O ----> Mg(OH)2 + H2
la 2 * 18 g H2O.....58 g Mg(OH)2........2 g H2
la 36 g H2O.........a g Mg(OH)2...........b g H2         a = 58 g Mg(OH)2 si 2 g H2