Feb mock Flashcards
Can ionic compounds conduct electricity?
Yes - in a molten or liquid state as the ions are free to move
However, not in a solid state as the ions aren’t able to move.
In an investigation with Carboxylic acids, why is it important to connect the gas syringe quickly?
To stop as little gas as possible from escaping.
Functional group of esters
COO
Three observations when Sodium reacts with water (GP 1 metal)
Sodium moves around the surface of water
Effervescence
Sodium eventually disappears
Why is Potassium more reactive than Sodium
-Potassium has one more shell than Sodium
-Therefore the attraction between outer shell and nucleus is weaker,
-meaning it is easier to lose the outer shell and break the attraction.
Why is aluminum malleable
Because the layers of ions can slide over each other.
What are the conditions needed for cracking
Temperature of 600-700C
Catalyst of Silica
How is crude oil separated into fractions?
-The crude oil is heated and vaporized
-The vapor is split into 6 columns based on boiling point, top is the lowest, bottom is the highest.
-The vapors then condense at their boiling points
Name two processes that occur before the solid lead iodide forms from crystallisation
Diffusion and dissolving
What is meant by the term functional group?
The part of a molecule that gives it its chemical properties.
Functional group for carboxylic acids
COOH
Functional group for Esters
COO
Functional group for alcohols
O-H
Substance needed for the fermentation of glucose
Yeast
Conditions needed for the fermentation of glucose
Anaerobic conditions (No oxygen)
30-40C so the yeast enzymes are at optimum temperature
How do we know when an ester is formed
A fruity smell is given off
Give one use of an ester
Used in cheap perfumes
Ethanol can be oxidized to produce a carboxylic acid
Give 2 of the reagents used in this oxidation reaction
Dilute sulfuric acid
Potassium Dichromate (IV)
Color change in the oxidation of ethanol
Orange —–> Green
Why is it better to heat the mixture using a water bath than with a Bunsen burner (Organic II)
Because alcohols are very flammable
Structural Formula for ethanol
CH3CH2OH
When Butanol reacts with Propanoic acid an ester forms, give the name of this ester
Butyl Propanoate
What is the chemical formula of the salt formed when Ethanoic acid reacts with Potassium Carbonate
CH3COOK
When an alcohol and a carboxylic acid react they form an ester and?
Water
Give two properties of a homologous series
They have similar chemical properties
They have the same functional group
How do you separate an insoluble solid from a liquid
Filtration
How do you separate Pure water from a solution
Simple distillation
seperatinga Liquid from a mixture of liquids with different boiling points
Fractional Distillation
Soluble solid from a solution
Crystallation
What precipitate is formed when you mix potassium chloride and ammonium carbonate
No precipitate
What precipitate is formed when you mix magnesium sulfate and barium chloride
Precipitate of Barium Sulfate
Test for Potassium
Flame test, dip flame in Dilute HCl then place over flame, flame turns lilac colour
Test for Sodium
Flame test, flame turns yellow
Carbonate test
Add dilute HCl and if Co2 is given off carbonate is present (test co2 by bubbling gas through limewater)
Halide test (Iodide, Chloride, Bromide)
-Add dilute nitric acid
-Add silver nitrate
-Iodide forms yellow precipitate, Bromide forms cream precipitate and Chloride forms white precipitate
Why are enthalpy change experiments carried out in polystyrene.
Polystyrene is a good insulator
Why do isotopes of bromine have the same chemical properties
They have the same number of electrons
What is a redox reaction
When one substance loses electrons and is oxidized and when the other gains electrons and is reduced.
What is a hydrocarbon
A compound that only consists of hydrogen and carbon atoms
Why is cracking an important process in the oil industry
Cracking produces shorter chains of hydrocarbons that are more useful
Alkanes are made and are useful for fuels
Alkenes are made and can be used to make polymers/Plastics
