C P1 -Chemical Changes Flashcards
What is the salt that comes from hydrochloric acid?
Hydrochloric acid = Chloride salt
What is the salt that comes from sulfuric acid?
Sulfuric acid = Sulfate salt
What is the salt that comes from nitric acid?
Nitric acid = Nitrate salt
What is the equation for neutralisation?
Neutralisation = sodium hydroxide + hydrochloric acid > sodium chloride + water
What is reduction?
Reduction is when oxygen is removed from a compound during a reaction
What is oxidation?
Oxidation is when oxygen is gained by a compound during a reaction
What charge are the ions which are produced by metals?
Metals produce positive ions when they react
How does the reactivity change in group 1 metals?
In group 1 metals, the reactivity increases down the group
What happens when group 2 metals react with acid?
When reacted with acid, group 2 metals fizz and their temperature increases
Does group 2 metals react with water?
Group 2 metals do not react with water
Does zinc, iron and copper react with water?
Zinc, iron and copper does not react with water
What happens when Zinc and Iron react with acid?
Zinc and iron react slowly with acid
Does copper react with acid?
Copper does not react with acid
What are metals called which are unreactive?
Unreactive metals are called native metals
What happens in a redox reaction?
In a redox reaction, the metal donates electrons to the hydrogen ions. This displaces hydrogen as a gas while the metal ions are left in the solution
What is a redox reaction between?
Redox reaction is between metals and acids
What is electrolysis?
Electrolysis is the process by which ionic substances are decomposed into simpler substances when an electric current passes through them
What are electrolytes?
Electrolytes are the free ions that comes from a melted or dissolved ionic compound, which can conduct electricity
What is a positive electrode called?
A positive electrode is called the anode
What is a negative electrode called?
A negative electrode is called the cathode
What are cations?
Cations are positive ions
What are anions?
Anions are negative ions
Where does the cation move?
The cation moves to the negative cathode
Where does the anion move?
The anion moves to the positive anode
What substance will be produced at the negative electrode if it is less reactive than hydrogen?
The negative electrode produces metals
What is produced from the positive electrode?
The positive electrode produces oxygen
What do the discharged ions depend on in aqueous solutions?
The discharged ions in aqueous solutions depend on the relative reactivity of the elements involved
What happens to strong acids in aqueous solutions?
In aqueous solutions, acids are completely ionised
What happens to weak acids in aqueous solutions?
In aqueous solutions, weak acids are partially ionised
How are soluble salts made?
Soluble salts can be made from reacting acids with solid insoluble substances eg metal and metal oxide
What is the process of making soluble salts?
Soluble salts are produced by adding solid to an acid until no more dissolves, and then filtering off excess solid and then crystallise to produce solid salts
What ions do acids produce?
Acids produce H+ ions (hydrogen ions)
What ions do alkalis produce?
Alkalis produce OH- ions (hydroxide ions)
How can you show what is happening at an electrode?
You can show what is happening at an electrode by using half equations
How can metals be extracted from molten compounds?
You can extract metals from molten compounds using electrolysis
When is electrolysis carried out to extract metals?
Electrolysis is carried out to extract metals when the metal is too reactive to be extracted by reduction with carbon
What is the issue with using electrolysis?
Electrolysis is expensive due to the large amount of energy needed to produce the electric current
What ions are involved in aqueous solutions?
In aqueous solutions, H+ and OH- ions are produced
What will happen to the metal if it is more reactive than hydrogen?
If the metal is more reactive than hydrogen, then hydrogen will form at the cathode
What will happen to the metal if it is less reactive than hydrogen?
If the metal is less reactive than hydrogen, then the metal will form at the cathode
What are the ions involved in brine (sodium chloride solution) (NaCl) ?
The ions involved in brine include, Na+, Cl-, H+, OH-
What will happen at the cathode during the electrolysis of brine? (sodium chloride solution)
At the cathode during the electrolysis of brine,2 H+ ions are gaining 2 electrons to form H2. This is because hydrogen always comes in pairs so the equation will have to be balanced. Also because they are at the cathode and hydrogen is a positive ion, it will be reduced and will gain electrons.
What will happen at the anode during the electrolysis of brine (sodium chloride solution)
At the anode during the electrolysis of brine, 2 CL- ions lose 2 electrons to form Cl2. This is because chlorine always comes in pairs so the equation will have to be balanced. Also because they are at the anode and chlorine is a negative ion, it will be oxidised and lose electrons.
What happens at the cathode in electrolysis?
In electrolysis, the cathode produces positive ions where they are reduced and gain electrons
What happens at the anode in electrolysis?
In electrolysis, the anode produces negative ions which are oxidised and lose electrons
What does the acronym PANIC stand for?
PANIC stands for positive is the anode, negative is cathode
What does the acronym OILRIG stand for?
OILRIG stands for oxidation is loss (of electrons), Reduction is gain (of electrons)
Which subatomic particle do acids produce in water?
Acids produce protons in water
Which type of solution do acids ionise in?
Acids ionise in aqueous solutions
What happens when strong acids ionise completely in water?
When strong acids ionise completely in water, all the acid particles dissociate to release H+ ions
What is a reversible reaction?
A reversible reaction is when the products can be turned back into the reactants, which sets up an equilibrium between the dissociated and undissociated acids.
If the concentration of H+ ions is high, what happens to the rate of reaction?
If the concentration of H+ ions is high, the rate of reaction will be faster
Why are strong acids more reactive than weak acids?
Strong acids are more reactive than weak acids because they have a high concentration of h+ ions and so the rate of reaction will be faster
For every decrease of 1 on the pH scale, the concentrations of H+ ions increases by _ _ _ _
For every decrease of 1 on the pH scale, the concentrations of H+ ions increase by a factor of 10
What does the concentration of an acid measure?
The concentration of an acid measures how watered down that acid is
