Chapter 5- Chemical Changes Flashcards
When is hydrogen gas given off of metal?
It si given off when mixed with dilute acids or water. It can be lighted with a splint
What is OILRIG
Oxidation is loss of electrons
Reduction is gain of electrons
How do different metals with different reactivates react with each other in an aqueous solution
A more reactive metal will displace a less reactive metal from its aqueous solution
What is oxidation?
The addition of oxygen
What is reduction?
The removal of oxygen
How does the reactivity series help determine how metal should be extracted from its ore?
The oxides of metals below carbon in the series can be reduced by carbon to give the metal element
Metals more reactive than carbon cannot be extracted from their ore via carbon, they are extracted via electrolysis
How is a salt formed?
It is formed when the hydrogen in an acid is wholly or partially replaced by metal or ammonium ions
How can a salt be made?
By reacting a suitable metal with an acid, the metal must be above hydrogen in the reactivity series, but not dangerously reactive.
Describe the process of making a salt.
The reaction between the metal and the acid produces hydrogen gas as well as a salt. A sample of salt can then be made by evaporating off the water
What is a redox reaction?
The reaction between a metal and an acid is a radix reaction.
The metal atoms lose electrons and are oxidised and the hydrogen ions from the acid gain electrons and are reduced
What happens when an acid reacts with a base?
A neutralisation reaction occurs.
What happens when an acid and a base react?
It produces salt and water
What is the sum of the charge on the ions in a salt?
It adds up to zero. It enables you to work out the formula for salts, knowing the charges on the ions present
How can you get a pure salt from an acid-base reaction?
It can be crystallised out of solution by evaporating off most of the water and drying it with tissue
Give two other reactions for making salts.
An acid and an alkali form a salt and water
An acid and a carbonate form a salt, water and carbon dioxide
