1. For each of the following experiment, state ONE observable change and write a chemical equation for the reaction involved.
a). Magnesium strip is added into dilute hydrochloric acid.
b). Iron (II) hydroxide is added into dilute sulphuric acid.
c). Sodium carbonate solution is added into concentrated hydrochloric acid.
d). Sodium hydroxide solution is added into copper (II) sulphate solution.
e). Calcium chloride solution is added into sodium sulphate solution.
唔識呀!!~要寫chem eq同changes 十大分
2007-08-21 5:59 am
回答 (3)
2007-08-21 6:44 am
✔ 最佳答案
a) Mg(s)+2HCl (aq) -> MgCl (aq) +H2(g)magnesium is dissolved
b )Fe(OH)2(s) + H2SO4(aq) -> FeSO4(aq) + 2H2O(l)
Iron (II) hydroxide is dissolved
c) Na2CO3(aq) + 2HCl (aq) -> CO2(g) + 2NaCl (aq) + H2O (l)
colourless gas is evloved.
d) 2NaOH(aq) + CuSO4 (aq) -> Na2SO4(aq) + Cu(OH)2 (s)
blue solid is formed.
e) CaCl2 (aq) + Na2SO4(aq) -> CaSO4(s) + 2NaCl(aq)
white solid is formed.
參考: my brain
2007-08-22 6:51 am
a)Mg(s)+2HCl(aq) -->MgCl2(aq)+H2(g)
Observation:magnesium dissolved and colouless gas bubbles evolved.
b)Fe(OH)2(s)+H2SO4(aq)-->FeSO4(aq)+2H2O(l)
Observation:green solid dissolved and the solution changed from colouless to green.
c)Na2CO3(aq)+HCl(aq)-->NaCl(aq)+H2O(l)+CO2(g)
Observation:colourless gas bubbles evolved.
d)2NaOH(aq)+CuSO4(aq)-->Na2SO4(aq)+Cu(OH)2(s)
Observation:blue solid formed
e)CaCl2(aq)+Na2SO4(aq)-->CaSO4(s)+NaCl(aq)
Observation:white precipitate formed
Observation:magnesium dissolved and colouless gas bubbles evolved.
b)Fe(OH)2(s)+H2SO4(aq)-->FeSO4(aq)+2H2O(l)
Observation:green solid dissolved and the solution changed from colouless to green.
c)Na2CO3(aq)+HCl(aq)-->NaCl(aq)+H2O(l)+CO2(g)
Observation:colourless gas bubbles evolved.
d)2NaOH(aq)+CuSO4(aq)-->Na2SO4(aq)+Cu(OH)2(s)
Observation:blue solid formed
e)CaCl2(aq)+Na2SO4(aq)-->CaSO4(s)+NaCl(aq)
Observation:white precipitate formed
參考: 自己
2007-08-21 7:50 am
a.Equation: Mg(s)+2HCL(aq)------------>MgCl2(aq)+H2(g)
Observable Changes: Colourless gas produced
B.Equation: FeOH(s)+H2SO4(aq)------------->FeSO4(aq)+H20(l)
Obsevable Changes: FeOH dissolved
C.Equation: Na2CO3(aq)+HCl(aq)------>NaCl(aq)+CO2(g)+H20(l)
Obsevable Changes: Effervescence
D.Equation: NaOH(aq)+CuSO4(aq)--------------->Na2SO4(aq)+Cu(OH)2(s)
Observable Changes: Blue sediment
E.Equation: CaCl2(aq)+Na2SO4(aq)--------------.CaSO4(s)+NaCl(aq)
Observable Changes: Write sediment
2007-08-20 23:58:45 補充：
Balanced Equation:Na2CO3(aq)+2HCl(aq)------>2NaCl(aq)+CO2(g)+H20(l)2NaOH(aq)+CuSO4(aq)--------------->Na2SO4(aq)+Cu(OH)2(s)CaCl2(aq)+Na2SO4(aq)--------------.CaSO4(s)+2NaCl(aq)a:Obsevable Changes:Colourless gas produced or Mg dissolved
Observable Changes: Colourless gas produced
B.Equation: FeOH(s)+H2SO4(aq)------------->FeSO4(aq)+H20(l)
Obsevable Changes: FeOH dissolved
C.Equation: Na2CO3(aq)+HCl(aq)------>NaCl(aq)+CO2(g)+H20(l)
Obsevable Changes: Effervescence
D.Equation: NaOH(aq)+CuSO4(aq)--------------->Na2SO4(aq)+Cu(OH)2(s)
Observable Changes: Blue sediment
E.Equation: CaCl2(aq)+Na2SO4(aq)--------------.CaSO4(s)+NaCl(aq)
Observable Changes: Write sediment
2007-08-20 23:58:45 補充：
Balanced Equation:Na2CO3(aq)+2HCl(aq)------>2NaCl(aq)+CO2(g)+H20(l)2NaOH(aq)+CuSO4(aq)--------------->Na2SO4(aq)+Cu(OH)2(s)CaCl2(aq)+Na2SO4(aq)--------------.CaSO4(s)+2NaCl(aq)a:Obsevable Changes:Colourless gas produced or Mg dissolved
參考: I study Chemistry
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