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Chemistry - D > Organic > Flashcards

Flashcards in Organic Deck (36):
1

Group 7 Halogens Reactivity

Decreases in reactivity
Increase in atomic radius
Increase in filled electron shells
Increase in melting point
Chlorine>Bromine>Iodine

2

Ionisation energy across period

Increases across
Nuclear charge increases
Shielding remains same
Atomic radius decreases
Electrons held more tightly and harder to remove

3

Ionisation energy down a group

Decreases down
Atomic radius increases
More shells as you go down the group
Electrons held more loosely and easier to to remove

4

Explain why (NH3) is polar

Dipoles do not cancel each other out

5

Define Electronegativity

Power of an atom to attract electrons in a covalent bond

6

Bonding of Ammonia and boiling point

NH3 is polar and can form hydrogen bonding

7

Trend in group 4 Hydrides and boiling points

Increases due to an increase in molecular mass, electrons increase which means more london forces

8

Explain why Silicon has high melting point?

Giant structure, strong covalent bonds require a lot of energy to break.

9

What is a Bronsted-Lowry acid?

Proton donor

10

Define Monobasic

Donates only one H+ ion to a base

11

Define pH

-log(H+)

12

Define Kw and write the expression

Ionic product of water
Kw = [H+][OH-]
[OH-]=[H+] in pure water

13

What is a buffer?

System that pH changes when small amounts of acid or a base are added

14

Normal pH of blood

7.35 - 7.45

15

Buffers in blood

H2CO3 and (HCO3)-

16

2SO2 + O2 -> 2SO3 Delta H = -98kJ
Effects on adjusting pressure and temperature

Increase pressure favours side with fewer moles. Yield increases as equilibrium moves to the right.

Increasing temperature. Yield would decrease as equilibrium would move to the left as reverse reaction is endothermic.

High Temperature is expensive and High pressure is dangerous.

Catalyst can be used to lower activation energy

17

Pattern in entropy

Decrease in entropy if (aq) forms (l) or (s). Solid is more ordered than liquid and aqueous.

Increase in entropy if (g) is formed from (s). Gas is less ordered than a solid.

18

Free energy/Gibbs
Define feasible

/\G = /\H - T/\S
Reaction may occur when /\G is negative

19

Standard conditions of Electrochemical cells

100KPA 298K 1MOLDM-3 of solution...
Platinum electrode

20

Standard electrode potential points

Negative reaction reverse, is oxidised and is strongest reducing agest
Positive stays same, is reduced and strongest oxidising agent

21

Acid equations

Strong acid [H+] = [HA]

Weak Acid Ka = [H+]^2/[HA]

[H+]^2= Ka x [HA]

22

Q = MC/\T

1) Work out Q first (remember M is mass of solution)
2) Work out moles of Metal X

Q divided by moles (If it is exothermic its negative!!)

23

Formation and combustion equations

Formation = Product - reactants
Combustion = Reactants - products

24

Percentage error

(Theoretical value - Experimental value) / Theoretical value x 100

25

Bond Enthalpy (H-H bonds etc)

Reactants - products

26

Define Dative(/coordinate) covalent bonding

A bond formed when one of the bonding atoms gives both of a pair of electrons.

27

Define Ligand

A molecule or ion that can donate a pair of electrons with the transition metal ion to form
a coordinate bond.

28

Standard Enthalpy of formation

one mole of a compound formed from its elements in
their standard states.

29

Conjugate Acid-Base pairs

In the forward reaction, the acid loses a
proton to form it’s conjugate base.
The base accepts a proton to form its
conjugate acid.

30

Ionic Bonding

E.g Nacl, MgCl2
High melting/boiling point
soluble in water
does not conduct electricity

31

Simple molecular

E.g CO2, I2, H2O
Low melting/boiling point
Does not conduct electricity

32

Giant covalent lattice

E.g Diamond, Graphite
High melting/boiling point
Does not conduct electricity (except graphite)
Not soluble in watewr

33

Metallic Bonding

E.g Fe, Mg, Al
High melting/boiling point
Electrostatic attraction between delocalised electrons and cations
Not soluble

34

Workout /\S (May help Gibbs equation after)

ΣS°(products) - ΣS°(reactants)

35

Workout pH of a buffer solution

pH = pka+log ([A-]/[HA])

[-log(Ka)] - [-log(BASE/ACID)]

36

PV=NRT

Pressure = pascals
Volume = M^3 [From Cm^3 to m^3 divide by 1,000,000]
N = Moles
R = 8.314
T = Kelvin [Celsius plus 273]