Top of the Bench - reactions Flashcards
what is a precipitation reaction?
when a solid is produced from two solutions
what technique would you use to recover the precipitate?
Filtration.
what is a neutralisation reaction
when an acids pH is brought towards 7 by reaction with a base (metal oxide, hydroxide or carbonate)
what are the products of a neutralisation reaction
-A salt and water
-If the base is a carbonate, C02 is also produced.
How do you extract a soluble salt after the reaction.
-Excess insoluble base is filtered out solution (excess neutraliser added to acid to ensure complete neutralisation).
-gently heat solution and allow liquid to EVAPORATE extract the dissolved salt.
what is a combustion reaction?
-a reaction when a substance releases energy when reacting with oxygen.
-all hydrocarbons are fuels and can combust - they produce C02 and water
what is an exothermic reaction?
-A chemical reaction which releases energy and causes temperature rise
what is an endothermic reaction
-A reaction that takes in energy and causes a temperature fall.
what is an addition reaction
-when an element is added over a carbon to carbon double bond
what is hydration
-type of addition reaction
-adding water
-alkene to alcohol
-opposite is dehydration
what is hydrogenation
-type of addition reaction
-adding hydrogen over the double bond
-alkene to alkane
what is halogenation
-type of addition reaction
-adding a halogen over double bond
-alkene to halogenalkane
what is the product of the reaction of ethene with hydrogen
ethane (hydrogenation)
what is the product of the reaction of propene and chlorine
1,2-dichloropropane (halogenation)
what is the product of the reaction of but-1-ene and fluorine
1,2-difluorobutane (halogenation)
what is the product of the reaction of but-2-ene and fluorine.
2,3-difluorobutane (halogenation)
what is the product of the reaction of ethene and water
ethanol (hydration)
what are flame tests
flame tests tell us the type of metal present due to the flame colour.
what is polymerisation
polymerisation is an addition reaction of many monomers making a polymer
what is a redox reaction
redox retractions involve an oxidation and a reduction reaction
name two gases which can form acid rain
sulfur dioxide and carbon dioxide, can dissolve in rain water and produce acid.
what can enzymes change glucose into
enzymes can change glucose into alcohol through the reaction of fermentation.
word equation for respiration (aerobic)
Glucose + oxygen –> carbon dioxide + water
what is the word equation of photosynthesis
carbon dioxide + water –> glucose + oxygen
during electrolysis what reaction occurs at the negative electrode
reduction (of the metal of the ionic compound)
during electrolysis what reaction occurs at the positive electrode
oxidation (of the non metal of the ionic compound)
