Chemistry: Post your doubts here!

[mehria]

Can anyone help me with this 3 (ii)? And can you tell me how reducing power or oxidising power is affected (increases or decreases) in oxides of these elements. (general trend?)
View attachment 40556
answer is : S or C or N or P

MnO4-, CrO42- ,Cr2O72- , HNO3, HClO4 ,HClO, NaClO, H2SO4, halogens, potassium nitrate, and nitric acid. are oxidising agents
where as halides, earth metals, formic acid, and sulfite compounds are reducing agents
hydrogen gas acts as an oxidizing agent when it combines with metals and as a reducing agent when it reacts with nonmetals

in ths question the answer can't be P... CO, NO, NO2 n SO2 or SO3 are all reducing agents

 

[princeali97]

Thats cuz you study 24/7 (just kidding)

hehe watever

 

[Mohammed salik]

MnO4-, CrO42- ,Cr2O72- , HNO3, HClO4 ,HClO, NaClO, H2SO4, halogens, potassium nitrate, and nitric acid. are oxidising agents
where as halides, earth metals, formic acid, and sulfite compounds are reducing agents
hydrogen gas acts as an oxidizing agent when it combines with metals and as a reducing agent when it reacts with nonmetals

in ths question the answer can't be P... CO, NO, NO2 n SO2 or SO3 are all reducing agents

gr8

 

[mehria]

gr8

thnk u ^.^

 

[sitooon]

45-47 marks. ON13 32

abby do the questions in P3 /m2 have to be in order ? or can we make our own?

 

[AbbbbY]

abby do the questions in P3 /m2 have to be in order ? or can we make our own?

Obviously any order. If someone doesn't know q1 they won't leave the entire paper now

 

[Suchal Riaz]

Thanks
Also
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_s11_qp_21.pdf
Question 3 d)
Isnt the salt in this part CaCl2 as they have referred to first reaction and that is formation of calcium chloride

no the reaction one of from W to Z
W is calcium nitrate and Z is calcium sulfate.

 

[sitooon]

Obviously any order. If someone doesn't know q1 they won't leave the entire paper now

Logic
What i was doing in P1 , was making some spaces inbetween question i dont know , and then reducing the size to fit the leaved space
No the task becam easier

 

[immie.rose]

Can anybody PLEASE explain how 1: 1.33: 1.61 = 6: 8: 7 ?

 

[Namehere]

Can anybody PLEASE explain how 1: 1.33: 1.61 = 6: 8: 7 ?

View attachment 40571
View attachment 40572

I´ve already answered this question a few times... Anyways. Here what you should be careful with is the accuracy. Maintain it with 3sf. So once you divide by the smallest number and get 1 : 1.33: 1.16 ratio you just have to convert these numbers into integers. You do it through trial and error until you get all integers. If you times everything by 6 you get an integer (or atleast really close to it).

Hope it helps.

 

[sudeep1097]

MnO4-, CrO42- ,Cr2O72- , HNO3, HClO4 ,HClO, NaClO, H2SO4, halogens, potassium nitrate, and nitric acid. are oxidising agents
where as halides, earth metals, formic acid, and sulfite compounds are reducing agents
hydrogen gas acts as an oxidizing agent when it combines with metals and as a reducing agent when it reacts with nonmetals

in ths question the answer can't be P... CO, NO, NO2 n SO2 or SO3 are all reducing agents

Thanks! but mark scheme says P as well and thanks for the general examples really helpful.
But incase of only *element oxides* in the given periodic table in question is there some kind of general trend on the reducing strength of the *element oxides*?

 

[itallion stallion]

Can someone plz upload notes or link of A2 organic reactions that contain complete condition like where to warm or heat and reflux etc.
Thanks in advance!

 

[itallion stallion]

Can someone plz help me with this May June 2010 paper 41 question 5ai, why are we not taking left electrode potential as +0.83v?Again in part B why not take Eo at cathode to be +0.13v.
Thanks in advance!

 

[sadiaali]

Please anyone do question Q 28 for me.Why cis-trans isomerism at the C=C double bond?
http://papers.xtremepapers.com/CIE/... AS Level/Chemistry (9701)/9701_s11_qp_13.pdf

 

[daredevil]

I´ve already answered this question a few times... Anyways. Here what you should be careful with is the accuracy. Maintain it with 3sf. So once you divide by the smallest number and get 1 : 1.33: 1.16 ratio you just have to convert these numbers into integers. You do it through trial and error until you get all integers. If you times everything by 6 you get an integer (or atleast really close to it).

Hope it helps.

so how do we decide when we can round off and wen we have to be extra careful about this stuff??

 

[Namehere]

so how do we decide when we can round off and wen we have to be extra careful about this stuff??

Why would you want to round off so early? Maintain the accuracy until the final answer.

 

[Mohammed salik]

Please anyone do question Q 28 for me.Why cis-trans isomerism at the C=C double bond?
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_s11_qp_13.pdf

I Think You are Referring to Q 27..
Look in every Ring there is Hydrogen at The Edges.. Which Forms cis-trans Isomerism.

 

[Snowysangel]

Um for silicon chlorides reaction with water, do we write Si(OH)4 as the product, or SiO2,?

 

[Snowysangel]

Why does ammonia react with NaCl but no with NaI? Isn't iodide more reactive than chloride due to its weaker bond energy? ANYONE?

 

[$$AK$$]

hey guys,
any tips for solving chemistry paper 1 and 2 ???
Thnx