Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Chemistry SL > Chapter 4, 5, 6, & 7 > Flashcards

Chapter 4, 5, 6, & 7 Flashcards

(57 cards)

Start Studying
1
Q

What does the strength of a metallic bond depend on?

A
  • the CHARGE of the ions
  • the RADIUS of the metal ion

sometimes the arrangement of the atoms is also important

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

does melting point increase or decrease from Al to Sn? (weird example)

A

it decreases due to arrangement of atoms

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

define alloy

A

homogenous mixtures of 2 or more metals, or of a metal & non-metal

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

when a substance more volatile?

A

when the attractive forces are weaker

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

why do longer chain alcohols become progressively less soluble in water?

A

due to the long hydrocarbon chains preventing hydrogen bonding b/w water molecules

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

What determines the melting points of ionic compounds?

A
  • the way the particles in the crystal state are packed together
  • impurities within the ionic compound
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

how do impurities affect ionic compounds?

A

they weaken the ionic compounds & result in lower melting points

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

why is ethanol a good solvent for substances?

A

because it has both polar & non-polar regions

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

what are negative ions sometimes known as?

A

they are known as acid radicals as they are formed when an acid loses one or more H+ ions

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

which are the strongest types of repulsions?

A

long-pair lone-pair repulsions are strongest due to the lone pairs being closer to the central nucleus & thus closer to the bonding electrons

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

what causes a polar bond?

A

may result from one end of the molecule being electron rich

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

give examples of resonance hybrids

A

ozone, benzene, carbonate ion, nitrate ion, & ethanoate ion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

List a few allotropes of carbon

A

diamond, graphite, graphene, C60 fullerene

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

characteristics of diamond

A

Giant covalent
Tetrahedral
Each C is joined to 4 others
Very high melting/boiling point
Does NOT conduct electricity
HIGHEST THERMAL CONDUCTIVITY
Insoluble in water or organic solvents
NO delocalised electrons

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

characteristics of graphite

A

Giant covalent
Trigonal planar
Hexagonal ring layers held tog. by weak LDF
High melting/boiling point
Conducts electricity + good lubricant (pencils)
High thermal conductivity
Insoluble in water & polar solvents
Delocalised electrons

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

characteristics of graphene

A

Giant covalent
Trigonal planar
Single layer of hexagonally arranged C atoms
High melting / boiling point
Conducts electricity
High thermal conductivity
Insoluble in water
Delocalised electrons

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

C60 fullerene

A

Molecular
Hexagons & pentagons – looks like ball
melting/boiling point not at high as other allotropes due to molecular structure - is soft
Does NOT conduct electricity (delocalised electrons cannot move b/w molecules)
Insoluble in water but soluble in some organic solvents like benzene
Delocalised electrons

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

characteristics of Silicon dioxide

A

Giant covalent
Tetrahedral around Si, bent around O
Each Si joined to 4 O atoms, each O joined to 2 Si atoms
High melting & boiling point
Does NOT conduct electricity
Very poor thermal conductor
Insoluble in water
NO delocalised electrons

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

are bonds in products or reactants stronger for EXOTHERMIC reactions?

A

bonds in products are stronger than bonds in reactants because heat is given out to surroundings

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

what are standard conditions?

A

101 kPa, 298 K

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

difference b/w heat & temperature

A

HEAT = total energy in a given amount of substance –> depends on amount of substance present

TEMPERATURE = average kinetic energy of substance, but is independent of amount of substance present

(two substances w/ dif volume could have same temp but dif heat)

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

Hess’s law

A

the enthalpy change for a reaction depends on the difference between the enthalpy of the products & the enthalpy of the reactants - is independent of the reaction pathway

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

define standard enthalpy change of formation

Study These Flashcards
A

the enthalpy change when 1 mole of the compound is formed from its elements in their STANDARD STATES at STP

24
Q

what is the enthalpy change of formation of Mg in standard state?

Study These Flashcards
A

0, since it is an element in standard form

25
define standard enthalpy change of combustion
enthalpy change when 1 mole of a substance is completely combusted in oxygen at STP
26
condition for calculating bond enthalpy
calculated in gaseous state
27
define average bond enthalpy
the energy needed to break 1 mole of a bond in a gaseous molecule AVERAGED over similar compounds e.g. must be gaseous NOT diatomic (F2)
28
limitations of using bond enthalpies
- the energy of a particular bond will vary in dif compounds - if more energy is required to convert gaseous water to liquid (to keep it in its standard state), this may require even more energy
29
significance of difference in bond enthalpies b/w ozone (resonance) & oxygen (double bond)?
it helps to protect us from the sun's UV rays The ozone layer protects the Earth from damaging UV radiation by absorbing both high & low energy UV light to break these bonds Ozone absorbs lower frequency / energy than oxygen & its bond is weaker
30
rate of production of ozone = ?
the rate of ozone destruction
31
what causes holes in the ozone layer?
human-made pollutants such as CFCs & oxides of nitrogen can disrupt this process of ozone production
32
how can rate of reaction b/w CaCO3 & HCl be determined?
- by measuring concentration of HCl - volume of CO2 produced - reduction in mass
33
the faster a particle moves . . .
the more KINETIC energy it possesses
34
Collision theory
- particles must collide - with appropriate geometry/orientation - collide w/ sufficient energy to bring about the reaction
35
why does temperature result in higher reaction rates?
more of the colliding particles will possess the necessary activation energy resulting in more successful collisions
36
why does the rate of reactions get slower as reaction proceeds?
the reactants get used up as their concentration decreases
37
transition point is . . .
the point at which products can form
38
slower reactions tend to have . . .
HIGHER Ea values
39
Faster reactions tend to have . . .
LOWER Ea values
40
does temperature have an effect on the Ea of a reaction?
NO
41
what causes the increase in average kinetic energy when temperature is raised?
the very high velocity
42
What is dynamic equilibrium?
- concentration of products & reactants is CONSTANT - forward & reverse reaction rates are EQUAL
43
example of physical equilibrium
condensation & vaporisation
44
requirement for equilibrium?
all reactants and products must be in SAME PHASE during equilibrium
45
closed system is important for equilibrium because. . .
neither matter nor energy can be lost or gained from system - MACROSCOPIC PROPERTIES ARE CONSTANT
46
examples of macroscopic properties
pressure, volume, temperature
47
What is Kc vs Qc?
Kc (constant at specific temperature) - how far a reaction proceeds Qc - in which direction the reaction will proceed to reach equilibrium
48
Le Chatelier's principle
- if a system at equilibrium is subjected to a small change, the equilibrium tends to shift so as to minimise the effect of that change
49
what is the value of Kc in esterification reactions?
it is 4 at 100C
50
if pressure is increased. . .
the position of equilibrium shifts to the side with less moles (MUST BE GASEOUS)
51
what happens to coloured solution if pressure is increased?
For a coloured solution, increasing the pressure will cause it to initially go a darker color until a new equilibrium is reached
52
effects of adding a catalyst on equilibrium
increases rate at which equilibrium is reached but has NO EFFECT ON POSITION of equilibrium (increases rate of both reverse & forward reaction equally)
53
When does Kc change?
ONLY WITH A CHANGE IN TEMPERATURE
54
effect on Kc when reaction is reversed
INVERT THE EXPRESSION (1/Kc)
55
effect on Kc when reaction coefficients are doubled
SQUARE THE VALUE OF Kc --> (Kc^2)
56
effect on Kc when reaction coefficients are halved
SQUARE ROOT THE VALUE OF Kc sqrt(Kc)
57
effect on Kc when 2 reactions are added together
MULTIPLE THE TWO EXPRESSIONS Kc1 x Kc2

Chemistry SL (5 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions