Weeks 3-4 (Electrolysis, endothermic/exothermic, rate of reaction) Flashcards
What does the atomic number of an element tell us?
The number of electrons in an atom
What does the group number of an element tell us?
The number of electrons in the element’s outer shell
At which electrode is a metal always produced during electrolysis?
The cathode
What two metals is hydrogen between in the reactivity series?
Zinc and iron
In the electrolysis of copper sulphate, what is produced at the:
a) Anode?
b) Cathode?
a) Anode = oxygen
b) Cathode = copper
In electrolysis, electrons are transferred from the anions to the __________.
In electrolysis, electrons are transferred from the anions to the ANODE.
What do periods tell us about an element?
How many electron shells it has
How does reactivity change down group 1 (alkali metals)?
Alkali metals lower down the group have higher reactivity
How does reactivity change down group 7 (halogens)?
Halogens lower down the group are less reactive
What are exothermic reactions?
Reactions that transfer energy into the surroundings
What are endothermic reactions?
Reactions that gain energy from the surroundings
In an exothermic reaction, products have a __________ energy level than the reactants.
In an exothermic reaction, products have a LOWER energy level than the reactants.
What is activation energy?
The amount of energy required to start/initiate a reaction
To break bonds between reactants, energy has to be supplied/released.
To break bonds between reactants, energy has to be SUPPLIED.
What is the definition for bond energy?
The amount of energy needed to break or form a bond
What is the unit for bond energy?
kJ / mol
What is rate of reaction?
How much product is formed or reactant is used up over time.
What is a tangent?
A line drawn against a curve on a graph to measure its gradient at that point
How does surface area change between lumps and powder?
Powder has a greater surface area than lumps
For reactants to react with one another, first they have to __________.
For reactants to react with one another, first they have to COLLIDE.
List five ways to increase the rate of reaction.
- Heating
- Increase surface area
- Increase pressure
- Catalysts
- Increasing concentration
Name 3 catalysts.
- Iron
- Platinum
- Vanadium oxide
When does increasing pressure not increase the rate of reaction?
When reactants are solids or liquids
