Metal Reactions with Water
- Learning objective: Understand the physical properties of metals.
- Learning objective: Understand the chemical properties of metals.
Reactions with Cold Water
- Potassium (K) reacts rapidly with cold water.
- 2K + 2H2O \rightarrow 2KOH + H2
- The reaction produces potassium hydroxide (KOH) and hydrogen gas (H₂).
- The solution turns alkaline (red litmus paper turns blue).
- The reaction is fast.
- Sodium (Na) reacts with cold water.
- 2Na + 2H2O \rightarrow 2NaOH + H2
- The reaction produces sodium hydroxide (NaOH) and hydrogen gas (H₂).
- The produced hydrogen gas ignites.
- Observation: Bubbles, fizzing.
- Turns the solution alkaline (red to blue).
Reactions with Hot Water
- Lithium (Li) reacts moderately with hot water.
- 2Li + 2H2O \rightarrow 2LiOH + H2
- Observation: Fizzing, bubbles, effervescence.
- Calcium (Ca) reacts with hot water.
- Ca + 2H2O \rightarrow Ca(OH)2 + H_2
Reactions with Steam
- Magnesium (Mg) reacts with steam.
- Mg + H2O \rightarrow MgO + H2
- Reaction is moderate.
- Iron (Fe) or Zinc (Zn) react slowly with steam.
- 3Fe + 4H2O \rightarrow Fe3O4 + 4H2
No Reaction
- Copper (Cu) does not react with water or steam.
- No reaction is observed.
- No fizzing or bubbles.
- No effervescence.