Metals and their Uses Flashcards
(76 cards)
What is the general equation for a metal reacting with an acid?
Acid + Metal → Salt + Hydrogen
How can you use acid reactions to determine metal reactivity?
More reactive metals react faster; very reactive ones (e.g., sodium) react explosively
Describe a practical to test metal reactivity with acids.
Use 3 boiling tubes with equal volumes of dilute HCl or H₂SO₄. Add same-sized pieces of Mg, Zn, and Fe
What does the speed of the acid reaction depend on?
The metal’s reactivity; faster bubbling = more reactive
How do you test for hydrogen gas?
Use a burning splint — a squeaky pop confirms hydrogen
Which metal reacts most vigorously with cold dilute acid?
Magnesium — produces loads of bubbles and loudest pop
How do zinc and iron react with dilute acids?
Slowly at room temperature, but more strongly when heated
What’s the general equation for metal and water reaction?
Metal + Water → Metal Hydroxide + Hydrogen
What happens with less reactive metals and steam?
Less reactive metal + steam → Metal Oxide + Hydrogen
Which metals react vigorously with cold water?
Potassium, sodium, lithium, calcium
What does the energy given out in water reactions tell you?
More reactive = more energy; potassium can ignite hydrogen
Do Mg, Zn, and Fe react with cold water?
No, but they do with steam
Does copper react with water or steam?
No
How can steam reactions be shown in the lab?
Use mineral wool soaked in water, heat the metal — bubbles of H₂ show reaction
What does the reactivity series show?
Metals in order of reactivity toward other substances
What type of metal will displace another from its oxide?
A more reactive metal displaces a less reactive metal
What kind of reaction is a metal displacement reaction?
A redox reaction — metal is oxidised, displaced metal is reduced
Example: What happens when iron oxide reacts with aluminium?
Aluminium oxide + iron are formed:
Fe₂O₃ + 2Al → 2Fe + Al₂O₃
What happens when you place reactive metal in a less reactive metal salt?
The more reactive metal displaces the less reactive one
Example: What happens when iron is added to copper sulfate?
Iron sulfate + copper
Fe + CuSO₄ → FeSO₄ + Cu
What happens if silver is added to copper sulfate?
Nothing — copper is more reactive, already in salt
What does temperature change in a displacement reaction tell you?
More reactive metal gives greater temperature change
How can displacement reactions help identify an unknown metal?
React it with different salts/oxides — its place in the reactivity series depends on whether it displaces or not
What is the order of the reactivity series?
K
Na
Li
Ca
Mg
Al
Zn
Fe
Cu
Ag
Au
