Chemistry Flashcards
What are the factors that increase the rate of reaction
- Temperature
- Concentration of reactants
- Pressure
- Surface area
- Catalysts
How does temperature increase the rate of reaction
Higher temperature = faster reaction. When the temperature increases, particles gain more kinetic energy and move faster. Faster movement = more collisions = higher speed of reaction.
How does concentration increase the rate of reaction
Greater concentration = faster reaction. When concentration increases, the number of particles increases. This increases the frequency of collisions which = higher speed of reaction.
How does pressure increase the rate of reaction
Reactions involving gases are affected by pressure. Higher pressure = faster reaction. When the pressure increases the number of particles increase. This increases the number of collisions.
How does surface area increase the rate of reaction
The smaller the surface area the faster reaction. In smaller particles, the surface area exposed is greater, so the chance that particles will collide is greater.
How do catalysts increase the rate of reaction
Catalysts increase the speed of reaction by providing an alternative pathway. It lowers the activation energy and does not undergo a chemical change
How do we measure the rate of reaction?
The rate of reaction = the change in product or reactant
———————————–
Time
What is a precipitation reaction?
When two solutions are mixed together, the ions are able to come into contact with each other. Oppositely charged ions attract. In some cases the attraction is strong enough to form ionic compounds. Some of these compounds are insoluble and so a solid called a precipitate is forms. Chemical reaction in which precipitates form are called precipitation reactions.
AgNO3(aq) + NaCl(aq) —-> AgCl(s) + NaNO3(aq)
Silver nitrate + sodium chloride = silver chloride + sodium nitrate
What is a corrosion reaction?
Corrosion is a chemical reaction in which a metal is ‘eaten away’ by a substance in the air or water. The tarnishing of silver jewellery and cutlery, rust are all examples of corrosion.
What is a displacement reaction?
When an element displaces another element from a compound a displacement reaction occurs.
Cu(s) + 2AgNO3(aq) —-> 2Ag(s) + Cu(NO3)2(aq)
Copper + silver nitrate = silver + copper nitrate
What is combustion reaction?
Combustion reactions are those in which a substance reacts with oxygen, and heat is released.
CH4(g) + 2O2(g) —> CO2(g) + 2H2O(l)
methane oxygen + oxygen molecules = carbon dioxide molecule + water molecule
What is the collision theory?
A chemical reaction can only take place when the reactant particles collide with each other with enough energy
What is a decomposition reaction?
In decomposition reactions, one simple compound breaks down into two or more simpler chemicals.
ZnCO3(s) —-> Zn(s) + CO2(g)
Zinc carbonate = zinc + carbon dioxide
What is a combination reaction?
Combination reactions occur when two elements combine to form a compound.
2Mg(s) + O2(g) —-> 2MgO(s)
What is a redox reaction?
Redox reactions occur when electrons are either completely or partially moved from one atom, ion or molecule to another. This is know as electron transfer. Loss of electrons is known as oxidation. Gain of electrons is known as reduction. Remember by the acronym OIL RIG. Oxygen involves loosing, reduction involves gaining.
Ag+ + Cl− —-> Ag+Cl
Ion, ion atom atom
