Chemical changes Flashcards
Metal+Oxygen–>
Metal oxide
Metal+Acid–>
Salt( compound name)+Hydrogen
Acid+ Carbonate–>
Salt+ Water+ Carbon Dioxide
Acid+ Metal Oxide–>
Salt+ Water
Acid+Hydroxide–>
Salt+ Water
Metal+Non- Metal
Metal Non- Metallide
Element+ Oxygen
Element oxide
Oxidation
Gaining of oxygen or gaining of a element
Reduction
If you loose a electron the element has been reduced
Reactivity series
How reactive are element in order
Reactivity series name em
Potassium Sodium Lithium Calcium Magnesium Zinc Iron Copper
Which elements react rapidly with water
Potassium
Sodium
Lithium
Reacts quite rapidly element
Calcium
No reaction with water elements
MAGNESIUM
Zinc
Iron
Copper
What makes a metal more reactive than other metals
When a metal reacts they lose electrons form positive ions
Reactivity of a metal depends on the ability to lose electrons and become positive ions
Which elements can be found in the earth as itself
Unreactive metals like platinum, gold and silver
This is because they don’t lose electrons that easily to become ions
A more reactive element will replace
A less reactive element in a compound
Ionic equations explain what…
what happens to each of the reactants during reactions
Reactions between metal and acids …
redox reactions. This displaces hydrogen as a gas while the metal ions are left in the solution.
salt from hydrochloric acid
chloride
salt from sulfuric acid
sulfate
salt from nitrate acid
nitrate
A base … an acid
neutralizes
reduction
when oxygen is removed or electrons are gained
oxidisation
when oxygen is gained and electrons are lost
Group 1 metal reaction with water
reactions get more vigorous as you go down the group
Group 2 metals react with water
Do not react with water
Zinc, iron, copper reaction with water
Do not react with water
Group 1 metal reaction with acid
reactions get more vigorous as you go down the group
group 2 metal reaction with acid
Observable reactions including fizzing and temperature increases
Zinc, iron, copper reaction with acid
Zinc and iron react slowly with acid. Copper does not react with acid
The reactivity of a metal…
refers to a tendency to form positive ions
why are copper and hydrogen in the reactivity series if they are non-metals
they can be used to extract some metal from their ores, depending on their reactivity
A more reactive element will… a less reactive element
displace
What will happen at the negative electrode in an aqueous solution
Metal will be produced on the negative electrode if the metal s less reactive than hydrogen if the metal more reactive hydrogen will be produced
What will happen at the positive elctrode in an aqueous solution
Oxygen is formed at the positive electrode unless it is haline( Chlorine, Iodine, Bromine)
Process of electrolosys
When an ionic compound is melted or dissolved in an aqueous solution, the ions are free to move. These are then able to conduct electricity and are called electrolytes. Passing an electric current through electrolytes causes the ions to move to the elcetrodes
Anode
Potitive electrode
Cathdoe
Negative electrode
Cations
positive ions that move to the negative cathode
Anions
Negative ions that move to the positive cathode
When is electrolysis used with molten compounds
When metal is too reactive to be extracted by reduction with carbon
What is titration useful for
To measure the precise volumes of acid and alkalis that react with each other
Titration method
1) Use the pipette to add 25 cm cubed of alkali to a conical flask and add a few drops of the indicator
2) Fill the burette with acid and note the starting volume Slowly add the acid from the burette to the alkali in the conical flask, swirling to mix
3) Stop adding the acid when the end-point is reached(the appropriate colour change in the indicator happens). Note the final volume reading. Repeat steps 1 to 3 until you get consistent readings.
Strong acid
Fully ionises in aqueous solutions
Weak acids
Only partially ionises in aqueous solution
The hydrogen concentration in acids
As the ph decreases by a unit ( becoming more acidic) the concentration of hydrogen increases *10
Soluble salts
Can be made from reacting on acid and insoluble substances like a metal
Production os soluble salts
Add the solid to the acid until no more dissolves. Filter of excess solid and then crystallise to produce solid salts.
What does acid produce in aqueous solutions
Hydrogen ions
What does alkalis produce in aqueous solutions
Hydroxide ions
