Alkali metals. Sodium and potassium
Answers are for parents and teachers.
1
Write the reactions K + H₂O, K + Cl₂ and K + S.
2K + 2H₂O → 2KOH + H₂↑; 2K + Cl₂ → 2KCl; 2K + S → K₂S.
2
Write the reactions of NaOH with CO₂ (excess and limited).
2NaOH + CO₂ → Na₂CO₃ + H₂O (little CO₂); NaOH + CO₂ → NaHCO₃ (excess CO₂).
3
How many grams of hydrogen are released when 11.5 g of Na is put into water? (A(Na) = 23)
0.5 g
4
Why must nobody experiment with sodium and potassium at home?
They react violently with water, the hydrogen burns or explodes, and the alkali formed causes burns.
5
Write the equations for the chain Na → NaOH → Na₂CO₃ → NaCl.
2Na + 2H₂O → 2NaOH + H₂↑; 2NaOH + CO₂ → Na₂CO₃ + H₂O; Na₂CO₃ + 2HCl → 2NaCl + H₂O + CO₂↑.