Question

What happens when zinc granules are treated with dilute solution of H₂SO₄, HCl, HNO₃, NaCl and NaOH Also write the chemical equations if reaction oçcurs.

Answer 1

• With dilute H₂SO₄: Hydrogen gas evolves - 
  `"Zn"("s") + "H"_2"SO"_4 ("dil".) -> "ZnSO"_4("aq") + "H"_2("g")`
• With dilute HCl: Hydrogen gas evolves -
  `"Zn"("s") + 2"HCl" ("dil".) -> "ZnCl"_2("aq") + "H"_2("g")`
• With dilute HNO₃: Nitrous oxide gas evolves. It is colourless.
  `4"Zn"("s") + 10"HNO"_3("aq") -> 4"Zn"("NO"_3)_2("aq") + 5"H"_2"O"("l") + "N"_2"O"("g")`
• With NaCl : There is no chemical reaction, with NaOH : Hydrogen gas evolves:
  `"Zn"("s") + 2"NaOH"("aq") -> underset("Sod. Zincare")("Na"_2"ZnO"_2("aq")) + "H"_2("g")`
• NaOH solution
  Zn(s) + 2 NaOH (aq) → Na₂ZnO₂(aq) + H₂