[pink_floyd]

anyone know how much practical is weighted in this? (AS) Because i got a C...oops :/

[EternalDoom]

20%

[786girl]

(Original post by kingam)
its brown your right then in cyclohexane it pink

lmao uve got ur colours mixed up, first u said yellow for cl now PINK for i2

[sarian2]

does anyone have the mark scheme to the specimen paper by any chance??

[arvin_infinity]

Scared of definitions !! pfff

[broken_glass_heart]

(Original post by pink_floyd)
anyone know how much practical is weighted in this? (AS) Because i got a C...oops :/

AS Practical is 20% of AS level.
U got a C, i messed up big time, i got 16/40 which is a U, which will b like 17/60, which is a bigger U.

[786girl]

(Original post by arvin_infinity)
Anyone knows how to do Q2 a iii jan 11

!! help me out pls

hi
ok so u kno that 0.00125 moles of HxA are used
and
0.0025 moles of NaOH

x is the number of H you need
simply divide 0.0025/0.00125
=2
so u need 2 moles of H to react with NaOH

i knoni havent explained it well, but wrn u see the word "deduce" or "determine"
they usually want u to use previous answers and either mtiply them or divide them
if ur unsure guess, in this case it would have been easy to guess and divide.

[786girl]

(Original post by sarian2)
does anyone have the mark scheme to the specimen paper by any chance??

markscheme is IN the question paper
scroll to the bottom its there

[786girl]

(Original post by arvin_infinity)
Scared of definitions !! pfff

lets revise them

define;
relative isotopic mass
and
mole

[INeedToRevise]

(Original post by broken_glass_heart)
AS Practical is 20% of AS level.
U got a C, i messed up big time, i got 16/40 which is a U, which will b like 17/60, which is a bigger U.

Are you an AS student or an A2 student?
Because I was in the same position as you and I had a U last year for my AS practical. My overall grade for AS was a D and now, with a resit of F322 and the practicals, I'm just a couple UMS of an A which is why I'm resitting this module tomorrow.

Its possible, just requires a lot of work.

[INeedToRevise]

(Original post by 786girl)
lets revise them

define;
relative isotopic mass
and
mole

Mole is the amount of substance containing as many particles as there are carbon atoms in 12g of the carbon-12 isotope.

Relative isotopic mass is the the mass of an atom of an isotope compared with one-twelfth of the mass of an atom of carbon-12.

Define first ionisation energy

[The medjai]

(Original post by INeedToRevise)
Mole is the amount of substance containing as many particles as there are carbon atoms in 12g of the carbon-12 isotope.

Relative isotopic mass is the the mass of an atom of an isotope compared with one-twelfth of the mass of an atom of carbon-12.

Define first ionisation energy

Energy required to remove one electron in each atom in one mole of gaseous atoms.

Mg + Cl2 = Mgcl2

What is oxidised and what is reduced?

[Eat.Sleep.Row.Repeat.]

(Original post by The medjai)
Energy required to remove one electron in each atom in one mole of gaseous atoms.

Mg + Cl2 = Mgcl2

What is oxidised and what is reduced?

Mg has been oxidised as it's oxidation number is increased. Cl2 has been reduced because it's oxidation number has decreased.

Describe the ammonia tests for the halides.

[TrampingRampage]

(Original post by The medjai)
Energy required to remove one electron in each atom in one mole of gaseous atoms.

Mg + Cl2 = Mgcl2

What is oxidised and what is reduced?

Mg is oxidised from 0 to +2
Cl is reduced from 0 to -1

Define electronegativity and dative covalent bond.

[DoDoBeDo]

First Ionisation Energy: The energy required to remove 1 electron from each atom in 1 mole of gaseous atoms to form 1 mole of +1 ions

& I want an A so bad in this module I was 2 marks of a B in January. But I've been doing past papers all weekend and have been getting a very steady 90-100%, and have worked out that I got 90UMS in 2 of the papers I've done [very bored with life so I decided to do that]. So I'm hoping for full UMS this time around, because I think F322 is going to kill me and I want good UMS in this one to kind of piggyback me a bit haha.

So hardcore revision has been happening, I'm going to school through lunch & both my frees tomorrow to study for it. Argh. I'm still just so angry with myself for January because I felt I did really well in that paper, apparently I've only just got the hang of 'describe' and 'explain' questions ha

[The medjai]

(Original post by TrampingRampage)
Mg is oxidised from 0 to +2
Cl is reduced from 0 to -1

Define electronegativity and dative covalent bond.

Electronegativity: The measure of attraction the bonded atom for the pair of electrons in a covalent bond.

Dative covalent bond: a shared pair of electrons provided by one of the bonding atoms only.

Explain the difference between the first ionisation energies of Li and Na (3).

[TrampingRampage]

(Original post by The medjai)
Electronegativity: The measure of attraction the bonded atom for the pair of electrons in a covalent bond.

Dative covalent bond: a shared pair of electrons provided by one of the bonding atoms only.

Explain the difference between the first ionisation energies of Li and Na (3).

Na has a larger atomic radius due to there being more inner electron shells and thus there is also more shielding. The nuclear attraction experienced by the outer electrons decreases and thus Na has a smaller first ionisation energy than Li as less energy is required to remove the outer electron.

Predict the bond angle in NH3 and explain why the molecule has this shape.

[dream_merchant]

(Original post by TrampingRampage)
Na has a larger atomic radius due to there being more inner electron shells and thus there is also more shielding. The nuclear attraction experienced by the outer electrons decreases and thus Na has a smaller first ionisation energy than Li as less energy is required to remove the outer electron.

Predict the bond angle in NH3 and explain why the molecule has this shape.

107. Pyramidal. 3 bonding electrons, 1 Lone pair of electrons. Electron pairs repel, Lone pairs repel more strongly than bonding electrons. Therefore the angle size decreases.

Define periodicity

[voices1]

(Original post by dream_merchant)
107. Pyramidal. 3 bonding electrons, 1 Lone pair of electrons. Electron pairs repel, Lone pairs repel more strongly than bonding electrons. Therefore the angle size decreases.

Define periodicity

it is the regular periodic variation of elements and their chemical properties based on their atomic number and their position in the periodic table

[Hannahbanna94]

Periodicity is the trend shown by periods in the periodic table (??)

Explain hydrogen bonding is and what special properties it gives to water/ice