Chemistry - Extraction of Metals & Reaction of Acids Flashcards
What is an “ore”?
An ore is a rock from which metal can be extracted from for profit.
What kind of state are most metals found in?
They are found in compounds with other substances, typically as an oxide - e.g.: iron oxide and aluminium oxide
How are metals extracted from their oxide compounds?
The oxygen is removed in a reduction reaction - the way this is done depends on how reactive the metal is
How are metals less reactive than carbon extracted?
By heating the metal oxide with carbon. E.g.: iron is extracted by heating iron oxide with carbon. Iron oxide undergoes a reduction reaction (therefore it gains electrons)
How are metals more reactive than carbon extracted?
Electrolysis
What is an acid?
A substance that produces hydrogen ions (H+) in aqueous solution (e.g.: HCl contains H+ ions)
What is an alkali?
A substance that produces hydroxide ions (OH-) in aqueous solutions. E.g.: NaOH contains Na+ and OH- ions
What is the pH scale?
The pH scale is a measure of how acidic or alkaline a solution is.
7 = neutral (H+ = OH- ions)
< 7 = acidic
> 7 = alkaline
It is a measure of how many hydrogen ions (H+) are in the solution.
What makes an acid a strong acid?
When an acid completely breaks down into its ions when in water.
E.g.: HCl is a strong acid as it fully breaks down into hydrogen and chloride ions
What makes an acid a weak acid?
When an acid only partially breaks down into its ions in water - e.g.: a small fraction of the molecules break into ions when in water.
What does dilute and concentrated means when talking about acids?
Dilute = a solution when theres a small amount of acid dissolved
Concentrated = a solution when there is a large amount of acid dissolved
What is made when a metal reacts with a dilute acid?
A metal salt and hydrogen.
What is made when an acid reacts with a metal hydroxide?
A metal salt and water
What is made when you react an acid with a metal oxide?
A metal salt and water
