Chemistry 2 - Chemical reactions and energy changes (C5 - C7) Flashcards
What gas is given off if metals react with water or dilute acids?
Hydrogen gas.
What does OIL RIG stand for?
Oxidation Is Loss, Reduction Is Gain (Of electrons)
What does it mean when a metal is found native?
Not found in an ore.
How do you extract metals more reactive than carbon from their ores?
Electrolysis
What is a salt?
Any chemical compound formed from the reaction of an acid with a base, with all or part of the hydrogen being replaced by a metal or other cation.
How do you make a salt?
Reacting a metal with an acid. The metal must be above Hydrogen in the reactivity series.
What does a metal and an acid make?
A salt + Hydrogen
What happens when an acid reacts with a base?
A neutralisation reaction occurs and there will be two products : A salt + water
What do the sum of the charges on the ions in a salt add up to?
Zero
What pH do acids have?
Lower than 7
What pH do alkalis have?
Above 7
What form do ionic compounds have to be in to be electrolysed?
Molten or dissolved in water.
What is the Anode?
The positive electrode
What is the Cathode?
The negative electrode
Where to the negative ions move to?
The positive electrode
Where do the positive ions move to?
The negative electrode
What happens to the positive ions at the negative electrode?
They gain electrons, so are reduced.
What happens to the negative ions at the positive electrode?
They lose electrons, so are oxidised.
What gas is made at the cathode?
Hydrogen gas
What gas is made at the anode?
Chlorine gas.
What is bond making? Exo or endo?
Exo thermic
What is bond breaking? Exo or endo?
Endothermic
What happens in an equilibrium reaction when you increase the temperature?
The endo thermic reaction’s rate will increase.
What happens in an equilibrium reaction when you increase the pressure?
The rate of the reaction which has more moles will increase. If the reaction is 1:1 there will be no change.
Name 6 ions that will be found in salts.
Halide ions (Halogens) Carbonate ions Sulphate ions Ammonium ions Metal ions Hydroxide
What is the charge of NO3?
1-
What is the charge of SO4?
2-
What is the charge of OH?
1-
What is the charge of H?
1+
What is the charge of NH4 (Ammonium)?
1+
