C2 Flashcards
What are the four main things that effect rate of reaction?
Temperature, presence of a catalyst, surface area and concentration.
How does increased temperature effect rate of reaction?
Particles gain energy (become less dense) and therefore move more quickly and hit each other more often, thus speeding up the reaction. At a higher temperature, more particles would have ACTIVATION ENERGY.
How does presence of a catalyst affect rate of reaction?
Lowers the amount of energy needed for reaction. Has no affect on ACTIVATION ENERGY.
How does surface area affect rate of reaction?
Larger surface area for particles to hit speeds up reaction. Has no affect on ACTIVATION ENERGY.
How does increased concentration/pressure affect rate of reaction?
Particles hit each other more often, speeding up reaction. No affect on ACTIVATION ENERGY.
Exothermic
Heat is given out
Endothermic
Heat is taken in
Uses of endothermic reactions
Thermal decomposition. Eg. sports injury packs.
Uses of exothermic reactions
Burning fuels (combustion), neutralisation and oxidation reactions. Eg. hand warmers and self heating hot drink cans
Giant Covalent Structure
Non-metal atoms joined by covalent bonds and arranged in a giant lattice formation.
Characteristics of giant covalent structures
Very high melting points with variable conductivity.
Equilibrium
When the forwards and backwards reactions in a reversible reaction happen at the same time. Think going up the down escalator.
Haber Process
Industrial process used to make ammonia by turning nitrogen in the air into ammonia. It is a reversible reaction.
Steps of the Haber Process
- Nitrogen and Hydrogen purified
2. Passed over an iron catalyst at high temp (45 degrees) or put under high pressure (approx. 200 atmospheres)
Yield
Amount of product formed in a chemical reaction
Examples of Giant Covalent Structures
Diamond, Silica and Graphite
Combustion
Burning a substance
Electrolysis
Decomposition of an ionic compound using electricity
Two electrodes in electrolysis
Anode (positive) and Cathode (negative)
Electroplating
Covering one substance with a thing layer of another using electrolysis
Acids
Ionic compounds, broken down so hydrogen ions dissolve into the liquid. The more hydrogen ions, the stronger the acid.
Alkalis
A solution containing a BASE. This is an ionic compound that falls apart to form hydroxide ions.
Mole=
RFM x specified number of moles
Neutron (charge and mass)
Charge: 0 (neutral) Mass: 1
Electron (charge and mass)
Charge: - (negative) Mass: negligable
Proton (charge and mass)
Charge: + (positive) Mass: 1
Isotopes
Atoms of the same element with the same number of protons and electrons but different numbers of neutrons.