Chemical Changes - Acids, Bases and REDOX reactions Flashcards
What is the pH scale used for?
To measure how acidic or Alkaline a solution is
From 0-14 (0 being most acidic)
How can you measure the pH of a Solution?
Using an indicator that changes colour depending on the certain pH of the solution.
What Ions form with acids in water?
H+ Ions
What is a base?
Any substance that will react with an acid to form a salt.
What Ions do Alkalis form in water
OH- Ions
What is Neutralization?
A reaction between acids and bases, the products will be neutral pH 7
What do acids do in aqueous solutions?
They ionise them
What do strong acids do in water?
They fully ionise, all acid particles dissociate to release H+ ions.
What do weak acids do in water?
They do not fully ionise, low amount of H+ ions formed
What type of reaction is the ionisation of weak acids?
Reversible Reaction
What does 1 decrease of 1 on the pH scale equate to?
The concentration of H+ ions increases by a factor of 10
How is the strength of an acid different from the concentration of acid?
Strength - the proportion of acid molecules ionise in water
Concentration - the amount of acid in a certain volume of water
What is formed when Acid reacts with a Metal Oxide?
Acid + Metal Oxide —> SALT + WATER
What is formed when Acid reacts with a Metal Hydroxide?
Acid + Metal Hydroxide ——-> SALT + WATER
What is formed when Acid reacts with a Metal Carbonate?
Acid + Metal Carbonate —-> SALT + WATER + CARBON DIOXIDE
What is the Reactivity Series?
It is a list that orders metals from most to least reactive
How is reactivity determined for metals?
How easily they lose electrons - forming positive ions
higher up the metal, the easier to lose an electron
Why is Carbon included in the reactivity series?
Metals less reactive than carbon can be extracted from the ores by reduction (with carbon). Those above cannot
Why is Hydrogen included in the reactivity series?
Metals more reactive than hydrogen will react with acids.
Metals less reactive will not.
What is formed when Acid reacts with a Metal?
Metal + Acid —-> SALT + HYDROGEN
What shows the speed of the reaction between acid and metals?
The rate at which hydrogen bubbles are given off.
What is formed when Metals react with Water?
Metal + Water —-> METAL HYDROXIDE + HYDROGEN
What is Oxidation? (in terms of electrons)
The loss of electrons
What is a Reduction? (in terms of electrons)
The gaining of electrons
How do metal ores less reactive than carbon extract?
The ore is reacted with carbon, which then becomes oxidised, which reduces the metal ore.
Leaving, the Metal and Carbon Dioxide
What does OIL RIG mean?
Oxidation Is Loss, Reduction Is Gain
What is a REDOX reaction?
When Oxidation and Reduction happen at the same time.
What is an example of a REDOX reaction?
All reactions between Metals with Acids
What is the Metal displacement rule?
A MORE reactive metal will displace a LESS reactive metal from its compound.
What happens to Metal Ions in a displacement reaction?
They gain electrons as they are reduced
What happens to Metal Atom in a displacement reaction?
They lose electrons as they are oxidised
