Chemistry: Post your doubts here!

[PhyZac]

I want exact definitions of relative atomic, isotopic, molecular and formula
masses, based on the 12C scale the way is should be answered ASAP! Thanks in advance

http://www.chemguide.co.uk/CIE/ exactly as the syllabus !

The relative atomic mass of an element is the weighted average of the masses of its isotopes on a scale on which a carbon-12 atom has a mass of exactly 12 units.

The relative isotopic mass of an isotope is the mass of the isotope on a scale on which a carbon-12 atom has a mass of exactly 12 units.

The relative molecular mass of a substance is the weighted average of the masses of the molecules on a scale on which a carbon-12 atom has a mass of exactly 12 units.

The relative formula mass of a substance is the weighted average of the masses of the formula units on a scale on which a carbon-12 atom has a mass of exactly 12 units.

 

[popcorn111]

Could anyone please tell for paper 5 what construction lines are and how to construct them?
And can anyone solve M/J 08 Q2.(f) please. So I get an idea on how to solve questions like these.
Thank You! ☺

 

[PhyZac]

Could anyone please tell for paper 5 what construction lines are and how to construct them?
And can anyone solve M/J 08 Q2.(f) please. So I get an idea on how to solve questions like these.
Thank You! ☺

The red lines are construction line ( what i learned)

 

[snoonono]

http://www.chemguide.co.uk/CIE/ exactly as the syllabus !

The relative atomic mass of an element is the weighted average of the masses of its isotopes on a scale on which a carbon-12 atom has a mass of exactly 12 units.

The relative isotopic mass of an isotope is the mass of the isotope on a scale on which a carbon-12 atom has a mass of exactly 12 units.

The relative molecular mass of a substance is the weighted average of the masses of the molecules on a scale on which a carbon-12 atom has a mass of exactly 12 units.

The relative formula mass of a substance is the weighted average of the masses of the formula units on a scale on which a carbon-12 atom has a mass of exactly 12 units.

Aah, thank you very much!

 

[popcorn111]

The red lines are construction line ( what i learned)

God bless you!

 

[knowitall10]

Can I get the link to the page or can any1 upload the organic chemistry reactions summarised in a single diagram

Here, I wrote this mnemonic down. you can decide which ones are in AS or A2...hopefully.
If you don't understand it, please let me know
I'll be happy to help.

 

[knowitall10]

Can I get the link to the page or can any1 upload the organic chemistry reactions summarised in a single diagram

Oh I'm sorry! Are you talking about the old textbook diagram i mentioned to ...someone up there?
Here it is... I snapped a pic of both the diagrams...

 

[Manobilly]

T

Here, I wrote this mnemonic down. you can decide which ones are in AS or A2...hopefully.
If you don't understand it, please let me know
I'll be happy to help.

Thanks

 

[Manobilly]

Oh I'm sorry! Are you talking about the old textbook diagram i mentioned to ...someone up there?
Here it is... I snapped a pic of both the diagrams...View attachment 24799

Both are good.I have the recent book so it didnt have it like this Searched net couldnt find it!
JazakAllah

 

[knowitall10]

Both are good.I have the recent book so it didnt have it like this Searched net couldnt find it!
JazakAllah

You're welcome
Hopefully we'll succeed in this world and the Hereafter!

 

[Tkp]

May june 11 53
1d(iiii)

 

[Alice123]

http://papers.xtremepapers.com/CIE/... AS Level/Chemistry (9701)/9701_s12_qp_23.pdf
Q5bii
A star (if u r free)
Im sorry for bothering you..... u must be busy with yr p1

 

[snowbrood]

Oh I'm sorry! Are you talking about the old textbook diagram i mentioned to ...someone up there?
Here it is... I snapped a pic of both the diagrams...View attachment 24799

from which book have u snapped this

 

[A star]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_s12_qp_23.pdf
Q5bii
A star (if u r free)
Im sorry for bothering you..... u must be busy with yr p1

no problem happy to help just pray for me that i get stright As .
well the reaction is dehydration hence it contains a alcohol and carboxylix acid and the alcohol is dehydrated to a double bond with this structure
CH2=CH-CO2H hope u get it

 

[strangerss]

hey everyone , please I have a doubt in p1 year 2002 MAY/JUNE , question 6 , I haven't got a clue how to solve it , can any one please help me out?

 

[iKhaled]

hey everyone , please I have a doubt in p1 year 2002 MAY/JUNE , question 6 , I haven't got a clue how to solve it , can any one please help me out?

alright see do uk the formula v1p1 = v2p2 ( we took that in IG physics)

before we connect the flasks we have 2(1) + 2(1) = v2p2 ( v2p2 are the values of the volume and pressure of gasses after connecting the flasks) when we connect the flasks the volume (v2) will be 1+2 =3

so 2(1)+2(1) = 3p2
p2 = 4/3 therefore the answer is A..did u get it ?

 

[hela]

CAN YOU TELL ME REACTIONS OF GROUP II AND PERIOD III WITH HCL AND H2O AND THEIR PH AND OBSERVATION IT IS CONFUSING

 

[hela]

CAN YOU TELL ME REACTIONS OF GROUP II AND PERIOD III WITH HCL AND H2O AND THEIR PH AND OBSERVATION IT IS CONFUSING

 

[iKhaled]

CAN YOU TELL ME REACTIONS OF GROUP II AND PERIOD III WITH HCL AND H2O AND THEIR PH AND OBSERVATION IT IS CONFUSING

SAME!! so confusing

 

[PANDA-]

CAN YOU TELL ME REACTIONS OF GROUP II AND PERIOD III WITH HCL AND H2O AND THEIR PH AND OBSERVATION IT IS CONFUSING

I second this