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general Chemistry Flashcards

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1
Q

What type of compound is electrolysis used on, and what is it used to do

A

ionic compound, it is used to separate the compound into the elements it is made of

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2
Q

What has to happen to the ions for electrolysis to happen, how does this happen

A

the ions have to be free to move around, this can happen through melting the compound or dissolving it in water

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3
Q

what are electrolytes

A

ionic compounds that dissolve in water to make a solution that conducts electricity

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4
Q

what is the difference between intramolecular forces and intermolecular forces

A

intramolecular forces are the forces between the atoms that makes up a molecule

intermolecular forces are the forces present between molecules

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5
Q

what are the properties of an ionic compound

A

ionic compounds can form giant lattices structures,
they have high melting and boiling point because the ions have a strong electrostatic attraction meaning a lot of energy is needed to separate the oppositely charged ions
cannot conduct electricity when solid because the ions are not free to move around, in order for the compound to conduct electricity it must be in a liquid state, this can be done by turning it in to a solution(dissolved in water) or melting it

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6
Q

what are the properties of transition metals

A

lower reactivity compared to alkali metals
higher density compared to alkali metals
stronger and harder compared to alkali metals
higher melting point than alkali metals
often used as catalyst
can form different colour compounds
can form ions with different positive charges

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7
Q

why is sodium more reactive that lithium

A

because it is a group 1 metal or alkali metal and these metals have one electron on the outside shell meaning in order for the element to be stable it has to lose that one electron, and sodium is below lithium on the periodic table meaning the outside electron shell is further away making the electron less strongly attracted to the positively charged nucleus, this is because it is greater distance from the positively charged nucleus

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8
Q

what happens when an alkali metal reacts with:
.water
.chlorine
.oxygen

A

with water the metal floats on the surface and melts creating a metal hydroxide, when reacting with water enough energy is released to melt the metal
with chlorine a metal chloride is formed, which dissolves in water to give a colourless solution
with oxygen the metal rapidly turns from silvery shiny to dull this is because a metal oxide is formed

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9
Q

why are covalent bonds strong

A

Covalent bonds are strong because the shared electrons are attracted to the nucleus of both atoms

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10
Q

what force is used in metallic bonds and why

A

electrostatic force it is between the positively charged metal ions and the negatively charged delocalised electrons

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11
Q

small molecules are often what states at room temperature? why is this

A

small molecules are often gas or liquid this is because they have low boiling and melting points

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12
Q

what tend to be the properties of substances with small molecules

A

substances with small molecules tend to have lower melting points and boiling points, and do not conduct electricity

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13
Q

why do big molecules have higher boiling and melting points than smaller molecules

A

big molecules attract other molecules with stronger intermolecular forces, this means they have a high melting and boiling point, big molecules also don’t contain delocalised electrons meaning they can’t conduct electricity

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14
Q

what are polymers

A

Polymers are large, chain like molecules that can extend for thousands of atoms
The intermolecular forces between polymer molecules are strong compared to the intermolecular forces between small molecules. This means that polymers melt at higher temperatures than substances with small molecules. They are solids at room temperature

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15
Q

what are some of the properties of giant covalent structures

A

no specific formula they can be any size
very high melting point
covalent structures exist as 1 large molecule or structure there is no intermolecular forces in them because it is just one molecule

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16
Q

what are some properties of pure metals

A

they have a high melting and boiling point because of the strong electrostatic forces between the positive metal ions and the negative delocalised electrons
they are also soft and malleable because the ions are the same size and are arranged in layers, they easily move over each other when a force is applied

17
Q

what are alloys

A

An alloy is a combination of 2+ elements, where at least 1 is a metal
the atoms of different elements are different sizes this makes them stronger than pure metals because it makes it harder for the layers to slide across each other

18
Q

what is graphite

A

Graphite is an allotrope (form) of carbon every atom is bonded to 3 other carbon atoms with a strong covalent bond
graphite is formed in layers of carbon with weak intermolecular forces this makes it soft
graphite conducts electricity because carbon is only bonded to 3 other carbon atoms meaning one electron is free to be delocalised

19
Q

what is Graphene

A

graphene is just one layer of graphite meaning it has weaker intermolecular bonds than graphite, it is lighter than graphite, more flexible than graphite and can conduct electricity because it has delocalised electrons

20
Q

what are fullerenes, and what can they be used for

A

a form of carbon having a large spheroidal molecule consisting of a hollow cage made up of sixty or more atoms
Catalysts
Lubricants
As vehicles for transporting drugs into our bodies

21
Q

what are Carbon nanotubes

A

Carbon nanotubes are fullerenes that take the shape of a cylinder.
They have a tiny diameter but can be incredibly long. they are also exceptionally strong for their size because of the covalent bonds and they can conduct electricity because of their delocalised electrons

22
Q

what are the uses of nano particles

A

deodorant
Catalysts
Transparent cosmetics
Computer chips
Delivery of medicines to specific areas of the body

23
Q

what is a exothermic reaction and what is a endothermic reaction

A

An exothermic reaction is when energy is lost from the reacting chemical in the form of heat
An endothermic reaction is when energy enters the chemical this usually results in loss of temperature

24
Q

what happens to the position of equilibrium if you increase the temperature of a reversible reaction

A

if you increase the temperature the position of equilibrium will change and because of Le Chatelier’s law the reaction will try to return to normal because of this the position of equilibrium will move towards the endothermic reaction which increases the amount of products made by the endothermic reaction

25
Q

what happens to the position of equilibrium if you increase the pressure in a reversible reaction

A

Pressure changes only affect reactions that involve gases. The position of equilibrium will shift to favour the reaction that produces the fewest gas molecules

26
Q

what happens to the position of equilibrium if you change the concentration of any product or reactant in a reversible reaction

A

Increase the concentration of a product will shift the position of the equilibrium towards the reactants

Increase the concentration of a reactant will shift the position of equilibrium towards the products

27
Q

how is the Haber process used and what temperature and pressure is it done at

A

The Haber process is used to manufacture ammonia according to the following equation.
N2(g) + 3H2(g) ↔ 2NH3(g). The reaction is exothermic in the forward direction
450 degrees Celsius 200 atmospheres of pressure

28
Q

what are the 3 isotopes of hydrogen and how many neutrons do they each have

A

Protium 0 neutrons
Deuterium 1 neutron
Tritium 2 neutrons

29
Q

what are the noble gases and what are their properties

A

The noble gases are a group of elements found in group 0 of the periodic table
All noble gases are colourless
They are monatomic (existing only as one atom) because they have a full outer shell because of this they have a low boiling point and a low density, both the boiling point and the density increase as you go down the period this is because the relative atomic mass increases

30
Q

what are halogens and what are their properties

A

The halogens are the elements found in group 7 of the periodic table
They are very reactive because they easily accept an electron into its outer shell, by gaining an electron they form a negative ion
As you go down the periodic table the reactivity of the halogen decreases this is because the atoms gain more electronic shells So, the distance between the outer electron shell and the nucleus increases this means that the attraction between the nucleus and the electron (to be gained from another element) decreases.
when a metal transfers its outer electron to the halogen a salt is formed

31
Q

what happens when lithium reacts with:
.water
.oxygen

A

Lithium burns with a crimson flame when it reacts with oxygen
Lithium floats on the surface of water and will release bubbles of hydrogen gas (it effervesces)

32
Q

what happens when sodium reacts with:
.water
.oxygen

A

The metal floats on the surface of the water, which releases enough heat to melt the sodium, the sodium moves quickly across the surface of the water
Sodium burns with a yellow flame when it reacts with oxygen

33
Q

what is ionic bonding and what type of elements does it involve

A

Ionic bonding involves an attraction between oppositely charged ions.
Ionic bonds are found in compounds made of metals and non-metals

34
Q

what is covalent bonding and what type of element does it involve

A

covalent bonding involves 2 atoms sharing 1 or more pairs of electrons
Covalent bonds are found in most non-metal elements and in non-metal compounds

35
Q

what is metallic bonding and what type of element does it involve

A

metallic bonding involves the electrostatic attraction between the negatively charged delocalised electrons and the positively charged ions
Metallic bonds are found in metals and alloys

36
Q

what are ions

A

Ions are particles that have a charge, they are created when an atom or molecule gains or loses electrons

37
Q

how are positive ions created and what are they called

A

Positive ions are usually created when an atom or molecule loses electrons.
Positive ions are also called cations.
The metals in Group 1 and 2 can easily lose electrons to become positively charged ions

38
Q

how are negative ions created and what are they called

A

negative ions are created when an atom or molecule gains electrons
positive ions are called anions
The non-metals in Group 7 are most likely to gain electrons to fill up their electron shell and become negatively charged

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