REDOX and Rust Flashcards
(15 cards)
How can the reactivity of a metal be determined using water?
Very reactive metals like potassium, sodium, and calcium react vigorously with cold water to form a metal hydroxide and hydrogen gas.
How can the reactivity of a metal be determined using dilute acid?
Reactive metals like magnesium, zinc, and iron react with dilute hydrochloric or sulfuric acid to form a salt and hydrogen gas.
What is observed in a displacement reaction between a metal and a metal oxide?
A more reactive metal will reduce the metal oxide, displacing the less reactive metal.
What is observed in a displacement reaction between a metal and a metal salt solution?
A more reactive metal will displace a less reactive metal from its salt solution.
What is the reactivity series of metals from most to least reactive?
Potassium > Sodium > Lithium > Calcium > Magnesium > Aluminium > Zinc > Iron > Copper > Silver > Gold
What conditions are needed for iron to rust?
Oxygen and water must be present.
How can rusting be prevented using barrier methods?
By coating iron with paint, oil, or plastic to prevent water and oxygen contact.
What is galvanising?
Coating iron with a layer of zinc to protect it from rusting.
What is sacrificial protection?
Attaching a more reactive metal (e.g. magnesium or zinc) which corrodes instead of iron.
What is oxidation (in terms of oxygen and electrons)?
Gain of oxygen or loss of electrons.
What is reduction (in terms of oxygen and electrons)?
Loss of oxygen or gain of electrons.
What is a redox reaction?
A reaction in which both oxidation and reduction occur.
What is an oxidising agent?
A substance that causes oxidation by accepting electrons.
What is a reducing agent?
A substance that causes reduction by donating electrons.
How do you investigate reactions between acids and metals like magnesium, zinc, and iron?
Add a small piece of metal to dilute hydrochloric or sulfuric acid
Observe the rate of hydrogen gas production
Faster bubbling = higher reactivity
Mg > Zn > Fe in reactivity
