Physics, Chemistry and Biology: Post your doubts here!

[Aafia Khan]

guyz ... whats the difference between SiO2 and SiO4?

 

[MMK95]

http://papers.xtremepapers.com/CIE/Cambridge IGCSE/Chemistry (0620)/0620_w08_qp_03.pdf

Q4 b i and ii
Q7 a i

Benzene is a hydrocarbon
100 - 92.3 = 7.7

92.3/12 : 7.7/1
7.1 : 7.7
1:1

Q7
1 mole of butane reacts with 6.5 moles of Oxygen
1 cm^3 of butane reacts with 6.5 cm^3 of oxygen ( Mole ratio and volume ratio are same )
10 cm^3 reacts with 65 cm^3
Oxygen left 100 - 65 = 35

1 cm^3 of butane forms 4 cm^3 of carbon dioxide
10 cm^3 forms 40 cm^3
CO2 formed = 40 cm^3

 

[ZaqZainab]

http://papers.xtremepapers.com/CIE/Cambridge IGCSE/Chemistry (0620)/0620_s08_qp_3.pdf question 8 part b iii
i know the answer but where do i learn more about this from?

 

[Iridescent]

http://papers.xtremepapers.com/CIE/Cambridge IGCSE/Chemistry (0620)/0620_s08_qp_3.pdf question 8 part b iii
i know the answer but where do i learn more about this from?

What more do you want to know about the topic? Any doubts or confusion?

 

[ZaqZainab]

What more do you want to know about the topic? Any doubts or confusion?

Yeah i have not found this topic in my book and i have no idea about how does synthetic polyamide look is it compulsory i don't even know how are they made

 

[Iridescent]

Yeah i have not found this topic in my book and i have no idea about how does synthetic polyamide look is it compulsory i don't even know how are they made

The example we need to know about a synthetic polymer with an amide linkage is nylon. Unlike proteins that are made of amino acids, nylon is amde of two types of monomers i.e., diamine (with an amino functional group on both sides of the monomer) and dicarboxylic acid (with an acidic functional group on both sides of the monomer).
Check this out:
http://www.google.com/url?sa=t&rct=...mIGgCA&usg=AFQjCNGD-UIPwhZH-TW7d-c_TL3gOCkXwg
Here they have written the formula of hexane and adipic acid. We don't have to show that, just put rectangular boxes in place of (CH2)4 but show the amino and the acid group.
Hope you got it.

 

[ZaqZainab]

Thanks

 

[Iridescent]

Thanks

You're welcome

I hope you know that we also need to know about the formula of terylene and how its formed as an example of synthetic polymer with an ester linkage. Just saying in case you don't know cz we still have time, you know.

 

[ZaqZainab]

You're welcome

I hope you know that we also need to know about the formula of terylene and how its formed as an example of synthetic polymer with an ester linkage. Just saying in case you don't know cz we still have time, you know.

i am not really good at chem thats the reason i never payed attention in class so damn i am all the way confused specially with those last chapters i do know about terylene though Thanks that site you shared is helping me out

 

[Iridescent]

i am not really good at chem thats the reason i never payed attention in class so damn i am all the way confused specially with those last chapters i do know about terylene though Thanks that site you shared is helping me out

You can ask for any help you need

 

[ZaqZainab]

You can ask for any help you need

Could you tell me what are the Definitions i should learn?
By now i have learned
Empirical formula
Molecular Formula
Homologous series
Relative Atomic Mass
Mole
Isotope
Anything else?

 

[Iridescent]

Could you tell me what are the Definitions i should learn?
By now i have learned
Empirical formula
Molecular Formula
Homologous series
Relative Atomic Mass
Mole
Isotope
Anything else?

Conductor
Electrolyte
Electrodes
Anode
Cathode
Acid
Alkali
Ionic bond
Covalent bond
Polymer
Endothermic reaction
Exothermic reaction
Equilibrium

 

[ZaqZainab]

Conductor
Electrolyte
Electrodes
Anode
Cathode
Acid
Alkali
Ionic bond
Covalent bond
Polymer
Endothermic reaction
Exothermic reaction
Equilibrium

Damn this list is so long have to make some place in my brain now for all this but i do know some of them not in right words
Now where have i left my brain?

 

[Iridescent]

Damn this list is so long have to make some place in my brain now for all this but i do know some of them not in right words
Now where have i left my brain?

It's okay. They don't demand exact words, Btw, there are some more:
Oxidation
Reduction
Oxidising agent
Reducing agent
Alloy
Rusting
Electroplating
Reversible reaction
Water of crystallisation
Redox reaction

 

[ZaqZainab]

When is covalent bounds, Metallic,Ionic,Giat macromolecular bounds formed?
Is there something called single covalent and double?
what i know is ionic is between metal and non metal
Gian macromolecular is between carbon and 4 other carbon which makes Diabmond it is tetrahedral
Metallic not quit sure but metal and metal (but is it even possible??)
Covalent non metal and non metal

 

[ZaqZainab]

Is it true than in a CELL
the negative electrode is the ANODE?

 

[ZaqZainab]

okay i am really annoying i need to Shut up!
Thanks for the help and sorry to disturb mak e you type all that
Best of luck for your exam

 

[Iridescent]

When is covalent bounds, Metallic,Ionic,Giat macromolecular bounds formed?
Is there something called single covalent and double?

Ionic bond: Between a metal and a non-metal. It is the transfer of electrons from the metal to the non-metal.
Covalent bond: Between two or more non-metals. It is the sharing of electrons between non-metals.
Metallic bond: Between the positive and the negative ions of a metal.
Giant macromolecular bonds are strong bonds between atoms of a compound or an element in a giant structure.

Yes, there are single, double, triple and quadruple covalent bonds that can be formed depending on the valency of the non-metal. Carbon can form covalent bonds as its valency is four.

 

[Reddah Nadeem]

Hey in my notebook i rote 200 atmospheres in contact process...
is this correct?
in my book it's written 1 atm?
Pleasse help! :/

 

[Iridescent]

Is it true than in a CELL
the negative electrode is the ANODE?

No, the positive electrode is an anode. However, only in a simple cell, anode is connected to the negative terminal of the voltmeter.