Crude oil is a mixture of hydrocarbons.
What is the general formula for the Alkanes?
Cn Hn+2
Cn H2n+2
Cn+2 Hn
What are isomers?
Compounds that have the same formula but different bonding.
Elements with the same number of protons but different numbers of neutrons.
Compounds containing hydrogen and carbon.
The high temperatures in a fractionating column are at the top.
In fractional distillation of crud oil, what are the characteristics of the small molecules? Tick 3 boxes.
Have low boiling point
runny
viscous
light in colour
hard to light
Name the fraction that does not evaporate during fractional distillation.
Bitumen
Gasoline
Refinery gases
Name the fraction that does not condense in fractional distillation.
refinery gases
bitumen
lubricating oil
What are the products of complete combustion?
Water
Oxygen
Carbon dioxide
Methane
Carbon monoxide
What are the products of incomplete combustion?
carbon monoxide
water
carbon dioxide
oxygen
methane
What is the definition on an isotope?
Atoms with the same number of protons but a different number of neutrons
Atoms with the same number of protons but a different number of electrons
Atoms with the same number of neutrons but a different number of protons
All of the elements in a period have the same number of electron shells
Reduction involves loss of electrons
Ionic bonding is between metals and non metals.
Positive ions and negative ions have weak electrostatic forces of attraction.
Non metals gain electrons to form negative ions called...
anions
cations
Ionic bonding is a strong electrostatic attraction between oppositely charged ions.
Ionic compounds have high melting and boiling points because of...
Weak electrostatic forces between oppositely charged ions
Weak forces of attraction between the molecules
Strong electrostatic forces between oppositely charged ions
What are the properties of ionic structures?
High melting points
Low boiling points
Conduct electricity when molten/dissolved in water
Crystalline solids
What is an electrolyte?
A substance which does not conduct electricity when molten or when dissolved in water, but does conduct electricity when solid .
A substance which does not conduct electricity when solid, but does conduct electricity when molten or when dissolved in water.
A substance which only conducts electricity when in gas.
When a metal atom becomes an ion it loses electrons.
Covalent bonding takes place between...
non metals only
metals only
metals and non metals
By sharing electrons, what are atoms trying to do?
To attain noble gas structure
To create compounds
To create strong bonds
In covalent bonding, the shared electrons are attracted by both nuclei, and this attraction forms the covalent bond.
Atoms bonded by covalent bonding form...
Molecules
Compounds
ions
The formation of a covalent bond is by the sharing of a pair of electrons between two atoms.
Covalent bonding is...
A strong attraction between the bonding pair of electrons and the nuclei of the atoms in the bond.
A weak attraction between the bonding pair of electrons and the nuclei of the atoms in the bond.
A strong electrostatic force between the bonding pair of electrons and the nuclei of the atoms in the bond.
What are the properties of molecular covalent species?
Low melting point
High boiling point
Usually solids
Usually gases or liquids
very poor conductors of electricity
Why do substances with simple molecular structures have low melting and boiling points?
They have weak bonds between atoms which are easy to overcome.
They have weak forces of attraction between molecules which require little energy to overcome.
Methane has a high boiling point because there are weak forces between the molecules
Why is hydrogen a gas at room temperature?
It has a low boiling point because it has simple molecular bonds are weak and require little energy to overcome
It has weak forces of attraction between molecules which require little energy to overcome.
Why does a substance like Magnesium Chloride have a high melting point.
It has strong electrostatic forces of attraction between ions.
It has strong bonds between molecules which require little energy to overcome.
It has strong forces of attraction between molecules which require little energy to overcome.
What are the properties of diamond - a giant covalent structure?
made from only carbon atoms
it is soluble in water
it has a low melting point
each atom forms four strong covalent bonds with its neighbours
it does not conduct electricity in any state
atoms form a rigid 3D structure
it is the softest material in the world
Why does diamond have a high melting point?
It has many weak covalent bonds.
It has strong forces of attraction between molecules.
It has many strong covalent bonds which need to be broken - this requires huge amounts of energy.
What are the properties of graphite?
carbon atoms form 3 covalent bonds with other carbon atoms
electrons hold layers together by a strong force
the free electron from each carbon atom is found in gaps between the layers
the layers can slide over each other easily
does not conduct electricity
layers of hexagons
in pencils
soluble in water
Allotropes are different forms of the same element, in the same physical state.
What are the properties of sand and quartz, silicon dioxide?
giant ionic structure
high melting point
tetrahedral structure
soft
insoluble in water
Why is it possible to use graphite to lubricate machines?
It is a liquid at room temperature so can help machines to slide.
Its structure consists of layers that slide over one another easily as they are held by a weak force
It contains a special substance which helps to lubricate the machines
Why can graphite conduct electricity?
It contains delocalised electrons (free electrons) which can move through graphite and carry charge.
It contains metal which is a good conductor of electricity.
It contains allotropes which carry charge from place to place through graphite.
What are the properties of metals?
shiny
bad conductors of heat and electricity
high melting and boiling points
ductile
strong
malleable
What is metallic bonding?
the chemical bond of two metals, creating a metallic compound
the electrostatic attraction between the positive metal ion and delocalised electrons
the strong force of attraction between two oppositely charged metal ions
Metal conducts electricity because the electrons are not free to move.
Fill the gaps: As you go 1)_________ the group 1 alkali metals, the atomic radius gets 2)___________ due to an extra filled electron shell.
1) Down
1) Up
2) Bigger
2) Smaller
In group 1 metals, the outer electron is less and less strongly attracted by the positive nucleus because it is further from the nucleus and is also shielded by the extra full electron shell of negative charge.
Fill the gaps: As you go down group 1 the elements become 1)________ reactive because it is easier to lose the electron from the outer shell and form a(n) 2)________
1) more
1) less
2) anion
2) cation
As you go ________ the group 7 halogens, the atomic radius gets bigger due to an extra filled electron shell.
Down
Up
As you go down the group, why do outer electrons become less and less strongly attracted by the positive nucleus?
The outer electrons are further from the nucleus and are shielded by the extra full electron shell of negative charge.
There are too many other electrons which are attracted to the positive nucleus.
The outer electrons are shielded by an extra full electron shell of positive charge.
Why do the elements become less reactive as you down Group 7?
dogs can fly
It is harder to attract an 8th outer electron, so it cannot fill its outer shell, so it cannot form a bond, so it is less reactive.
What are the properties of group 1 metals?
alkali
low melting points
hard
most reactive group
blue compounds
low densities
Group 1 metals react vigorously with water to produce an alkaline metal hydroxide and hydrogen gas. Which of these best describes the reaction of potassium with water?
Floats on the surface, gently fizzing and giving off hydrogen.
It gets so hot it melts itself when it reacts. Fizzes on surface rapidly.
Gets so hot that it lights the hydrogen gas given off. Burns with a lilac flame.
Click the correct statements. At room temperature...
Fluorine is a pale yellow gas
Chlorine is a blue gas
Bromine is a brown/red dense liquid
Iodine is a grey solid
Astatine is a white sold
In halogen displacement reactions, the more reactive halogen prefers to be in the compound.
Group 7 elements react vigorously with group 1 elements like sodium and potassium. When they do react, what is formed?
A metal compound
A metal halide
A metal halogen
When halogens react they GAIN electrons, turning into halides. (reduction)
Halides GAIN electrons when they become halogens. (oxidation)
Select the correct way of expressing the reduction of Bromine (halogen) to Bromide (halide).
Br2 + 2e- → 2Br-
Br2 → 2Br- + 2e-
Br2 - 2e- → 2Br-
Hydrogen Chloride dissociates in water (polar solvent) to form separate ions: H+ and Cl-. The H+ has acidic properties in water, turning...
Blue litmus paper blue
Blue litmus paper red
Red litmus paper blue
When Hyrdrogen Chloride gas is dissolved in Methyl-benzene, why does the blue litmus paper stay blue?
Methyl-benzene is a polar solvent
The HCl does not dissolve properly
Methyl-benzene is a non-polar solvent
Select the correct order of the reactivity series.
Potassium, Sodium, Lithium, Calcium, Magnesium, Aluminium, Silver, Gold, Platinum, Zinc, Iron, Lead, Copper
Potassium, Sodium, Lithium, Calcium, Magnesium, Aluminium, Zinc, Iron, Lead, Copper, Silver, Gold, Platinum
Potassium, Magnesium, Aluminium, Sodium, Lithium, Calcium, Zinc, Iron, Lead, Copper, Platinum, Silver, Gold,
Por favor espera - en proceso…