Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Chemisty > Unit 1 higher > Flashcards

Unit 1 higher Flashcards

1
Q

Activated complex

A

the activated complex is a very unstable arrangement of atoms

formed at the maximum of the potential energy barrier, during a chemical reaction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Activation energy

A

is the minimum kinetic energy required by colliding particles before reaction will occur

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Allotrope

A

one of two or more existing forms of an element

E.g diamond

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Collision theory

A

for a chemical reaction to occur, particles must collide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Covalent bond

A

Shared pair of electrons between non-metals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Covalent radius

A

half the distance between the nuclei of two bonded atoms of an element

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Delocalised

A

Electrons or ions that are free to move im metallic and ionic bonds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Desorption

A

occurs when the bonds between the molecules and the surface break and the molecules leave the surface of the catalyst

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Dipole

A

atom or molecule in which a concentration of positive charges is separated from a concentration of negative charge

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Electronegativity

A

measure of the attraction that an atom involved in a bond has for the electrons of the bond

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Enthalpy change

A

change in heat energy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Hydrogen bonds

A 
Percent dipole - dipole interactions 
Strongest type of intermolecular bond
Occurs when hydrogen atoms is covalently bonded to a highly electrgravitive element
Oppositely charged end attract
Eg water, ammonia, alcohols
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Intermolecular forces

A

forces of attraction which exist within a molecule

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Ionisation energy

A

energy required to remove one mole of electrons from one mole of atoms in the gaseous state

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Isoelectronic

A

having the same arrangement of electrons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

London dispersion forces

A

Weakest type of intermolecular bond
Between atoms and molecules
Molecular elements (eg oxygen) + monatomic elements (eg noble gases) will form solids if cooled at sufficiently low temp, freeze at absolute 0
Caused by uneven distribution of electrons within an atom
Temporary dipoles form

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Lone pairs

A

pairs of electrons in the outer shell of an atom which take no part in bonding

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Polar covalent bond

A

covalent bond between atoms of different electronegativity/elements
uneven distribution of electrons
Soluble in water + polar covalent

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Ways a coarse of a reaction cab be followed

A

Gas produced
Change in mass
Change in temp
Change in colour

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Relative rate

A

1/t

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Average rate

A

Change in quantity/change in time

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Why is it important to industry to be able to control the rate of a chemical reaction

A

If the rate is too low it may not be economically viable

If the rate is too hi there is a risk of thermal explosion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Variables that can affect rate of reaction

A 
Temp
Collision geometry
Catalyst
Pressure
Surface area 
Concentration
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Is enthalpy change positive or negative in a exothermic chemical reaction

A

Positive

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Is the enthalpy change of and endothermic reaction positive or negative

A

Negative

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Change in enthalpy =

A

Ep - Ea

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Kinetic energy

A

The energy in a moving object

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

How does a catalyst speed up the rate of a chemical reaction

A

Lowers the activation energy so the particles need less energy for the reaction to occur

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

When there is an increase in temperate on how does it affect the energy distribution diagram

A

The higher temperature means particles have more Kentucky energy decreasing the activation energy

30
Q

Repulsive force pretiöses must overcome is due to

A

Repulsive force from outer electrons

31
Q

Collision geometry

A

The particles must face the right way so the activated complex can be formed

32
Q

Periodic table (ionisation energy)

A

Horizontal - increases

Vertical - decreasing

33
Q

Periodic table (covalent radius)

A

Horizontal - decreases

Vertical - increases

34
Q

Periodic table (electron gravity)

A

Horizontal - increases

Vertical- decreases

35
Q

Pure covalent bonds

A

Excites between 2 atoms with the same electron gravities
No ionic character
E.g diatomic elements
Electrons shared equally

36
Q

Ionic bonding

A

Uneven share of electrons (even more than polar covalent)
Large difference in electron gravity
Between metal + non-metal
Element with larger electron gravity pulls
electrons from smaller element
High mp/BP
Soluble in water + polar covalent Solvents

37
Q

Difference in electron gravity most to least

A

Ionic - high
Polar covalent - low
Pure covalent zero

38
Q

Van der walls forces

A

Intermolecular forces

39
Q

Permanent dipole permanent dipole interactions

A 
Molecules with a permanent dipole
Attraction between the oppositely charged end of molecules
Molecules are unsymmetrical 
Stronger than london dispersion forces
Form permanent dipole
40
Q

Bonding strengths low to high

A

Loben dispersions forces
Permanent dipole interactions
Hydrogen bonds
Covalent bonds

41
Q

properties of water

A

Ice less dense than water ( because water expands as it is frozen )
High surface tension - iron pin floats on water + how insects walk on water
relatively high viscosity

42
Q

Why do metallic bonds conduct electricity

A

When atoms loose one or more electrons they become positively charged
Ions are now attracted to the pool of electrons
These electrons are now free to move
Causing them to conduct

43
Q

Why does aluminium conduct better than sodium

A

Aluminium has three outer electrons whereas sodium has one, when theses electrons delocalise aluminium has a higher conductivity

44
Q

Why do metals shine in sunlight

A

Metal absorbs light energy and re-emits it

45
Q

What intermolecular forces does covalent bonds have

A

Non-polar

46
Q

How does graphite conduct electricity

A

Delocalised electrons are held weakly, that can flow across layers

47
Q

Covalent network structures

A

Diamond
Carbon graphite
Silicon
Boron

48
Q

What happens when noble gases have electricity pass through them

A

They emit light

Eg outdoor signs

49
Q

Factors considered to see atomic size

A

Nuclear charge on an atom

The number of filled electron shells

50
Q

Ionisation energy factors must be considered

A

The nuclear charge of the atom
The number of filled electron shells
The size of the atom

51
Q

Electron gravity factors must be considered

A

The nuclear charge of an atom
The number of filled electron shells
The size of the atom

52
Q

What increases when a chlorine atom becomes a chlorine ion

A

The number of full energy levels

53
Q

Why does electron gravity increase across the period table

A

Positive nuclear charges increases

54
Q

Which element has the highest electron gravity value

A

Fluorine

55
Q

Why is there an increase in covalent radius going down a group

A

Increase in the number of electron shells

56
Q

Why does covalent radius decrease going across a period

A

The number of nuclear charge increases

57
Q

Why does the first ionisation energy of elements tend to decrease as you go down a group

A

Number of electron shells increase

Outer electrons are less stronger held

58
Q

Why first ionisation energy of elements tend to increase as you go across period

A

Number of nuclear charge increases

Pulls the outer electron close to the nucleus

59
Q

How can ionic bonds form covalent bonds

A

By sharing electrons

60
Q

What do more electron gravities elements do

A

Elect with greater value of electron gravity is more likely to gain electrons from a negative ion and the element with the smaller value is most likely to loose electron forming a positive ion

61
Q

How to tell if an element is covalent or ionic

A

If the tall charge of ions is 0 then it is ionic bonding

62
Q

Boiling points of polar and non-polar compounds

A

Polar has higher boiling point and higher viscosity than non-polar

63
Q

Thermite reaction

A

Highly exothermic reaction

Displacement reaction

64
Q

Reducing agents

A

Substance which donates electrons

Elements with low electron gravity

65
Q

Oxidising agent

A

Substance which accepts electrons

Elements with high electron gravity

66
Q

Why does boiling point increase going down group 7

A

The number of occupied electron shells increases
Increasing the number of electrons
Increasing the strength of LDF’s between molecules
Requiring more energy to break

67
Q

Explain fully the increase between the 5th and the 6t ionisation energy of carbon

A

The state first energy level with 2 electrons is being broken so more energy is required

68
Q

Why does the ionic radius of phosphorus greater than aluminium

A

Phosphors has more outer electrons and is negatively charged, this attracts the electrons from aluminium more strongly

69
Q

Why does ammonia have a high melting point

A

Ammonia has. Hydrogen bonding
The nitrogen is bonded to hydrogen
LDF’s between molecules are extremely strong
Requires a lot of energy to break

70
Q

Covalent bonds

A

Shared par of electrons between positive nuclei and delocalised electrons
Held together by the attraction between their positive nuclei and negatively charged shared pair of electrons
Is atoms are too close, nuclei will repair each other
If too fat parts, the nuclei will not attractnon-polar

Chemisty (18 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions