C5 Flashcards
How are metal oxides produced and what type of reaction is it
Metals react with oxygen to produce metal oxides. The reactions are oxidation reactions because the metals gain oxygen.
What is oxidation and reduction in terms of oxygen
Oxidation is gain of oxygen, reduction is loss of oxygen
How is the reactivity of a metal decided
The reactivity of a metal is related to its tendency to form positive ions
How are metals’ relative reactivity found out and put in a list ( give examples )
The metals potassium, sodium, lithium, calcium, magnesium, zinc, iron and copper can be put in order of their reactivity from their reactions with water and dilute acids
The reactions of metals with water and acids are limited to room temperature and do not include reactions with steam
What are displacement reactions
A more reactive metal can displace a less reactive metal from a compound.
How are metals found in the ground
Unreactive metals such as gold are found in the Earth as the metal itself but most metals are found as compounds that require chemical reactions to extract the metal.
How are metals less reactive than carbon extracted
Metals less reactive than carbon can be extracted from their oxides by reduction with carbon
What is oxidation and reduction
Oxidation is the loss of electrons and reduction is the gain of electrons.
OILRIG
What do acids react with some metals to get and what type of reaction is this
Acids react with some metals to produce salts and hydrogen
This is a redox reaction
Metals less reactive than hydrogen will not react because they will not displace it from the acid to form a salt
Alkali + acid
Salt + water
Base + acid
Salt + water
What are bases and what are examples of bases
A base is anything that reacts with acid to form a salt
Insoluble metal hydroxides
Metal oxides
Metal carbonates
What are alkalis
Soluble metal hydroxides
Metal carbonate + acid
Salt + water + carbon dioxide
How are soluble salts made
Soluble salts can be made from acids by reacting them with solid insoluble substances, such as metals, metal oxides, hydroxides or carbonates
What do acids produce in aqueous solutions
Acids produce hydrogen ions (H+) in aqueous solutions
What do alkalis produce in aqueous solutions
Aqueous solutions of alkalis contain hydroxide ions (OH–)
What is used to measure acidity or alkalinity
The pH scale from 0 - 14
Strong acid : 0
Strong alkali: 14
What is the value of neutral on the pH scale
pH 7 is neutral
What happens in a neutralisation reaction between an acid and alkali
In neutralisation reactions between an acid and an alkali, hydrogen ions react with hydroxide ions to produce water
The products are also neutral ( pH 7)
What do strong acids do in aqueous solutions
A strong acid is completely ionised in aqueous solution. Examples of strong acids are hydrochloric, nitric and sulfuric acids.
What do weak acids do in aqueous solutions
A weak acid is only partially ionised in aqueous solution, the reaction is reversible. Examples of weak acids are ethanoic, citric and carbonic acids.
What happens to the hydrogen ion concentration as the pH decreases
As the pH decreases by one unit, the hydrogen ion concentration of the solution increases by a factor of 10
For a decrease on tbe pH scale by 2, the concentration of hydrogen ions increases by a factor of 100
What is different about the terms dilute/ concentrated and weak/ strong
Dilute/ concentrated refers to the amount of substance
Weak/ strong refers to the degree of ionisation
What are the symbols for the following ions: Ammonium Nitrate Sulfate Carbonate Phosphate
Ammonium: NH4+ Nitrate: NO3- Sulfate: SO42- Carbonate: CO32- Phosphate: PO4 3-
Whats the rule/ equation with pH change and H+ concentration change
Factor H+ ion concetration changes by = 10^-x
x being the different in pH
Metal + acid
Salt + hydrogen
Metal + water
Metal hydroxide + hydrogen
