Biology; Chemistry; Physics: Post your doubts here!

[legion]

you are calling your bro crack btw thank you

welcome. by crack i meant that who answer a simple question with so many complex terms??

 

[legion]

Hope your brother doesn’t read that

he wont. though i wish he would. n trust me, i have told him a thousand times that he is. so no worries. =)

 

[Tharindu]

Explain charging of solids involve movement in electrons
Describe the separation of charges by induction
Describe examples where charging could be a problem.eg.lightning
Please answer these

 

[multixamza01]

Chemistry 5070
May/June 2005 Paper 4
Q3 c) i)

Shouldn't the answer be Oxygen? The Hydroxide Ion is more Reactive then the Chloride Ion, and unless sodium chloride is concentrated, it wouldn't get discharged. So why does the marking scheme say chlorine is the answer?

 

[fatikhalid]

it is the usual acid catalyst for the conversion ofcyclohexanone oxime to caprolactam, used for making nylon. It is used for making hydrochloric acid from salt via the Mannheim process. Much H2SO4 is used in petroleum refining, for example as a catalyst for the reaction of isobutane with isobutylene to give isooctane, a compound that raises the octane rating of gasoline

when did v read ds??..o_0

 

[fatikhalid]

CaO is also used but others are relatively used more

thankyou soo much!!..

 

[legion]

when did v read ds??..o_0

hahaha dunt worry. read ma post. meine fahad bhai se question pucha tha n usne ye bola tha so i copy pasted the same answer. wo zara apne dimag wale answer karta ha na. dunt worry. we jes read the overview ov these =)

 

[fatikhalid]

hahaha dunt worry. read ma post. meine fahad bhai se question pucha tha n usne ye bola tha so i copy pasted the same answer. wo zara apne dimag wale answer karta ha na. dunt worry. we jes read the overview ov these =)

hahaha ritie!..

 

[scouserlfc]

Chemistry 5070
May/June 2005 Paper 4
Q3 c) i)

Shouldn't the answer be Oxygen? The Hydroxide Ion is more Reactive then the Chloride Ion, and unless sodium chloride is concentrated, it wouldn't get discharged. So why does the marking scheme say chlorine is the answer?

See this in any aqueous solutions the discharge occurs like in concentrated solutions so if it says aqueous solution of sodium chloride then chlorine discharges like in concentrated solutions remember this as a rule

 

[scouserlfc]

Explain charging of solids involve movement in electrons
Describe the separation of charges by induction
Describe examples where charging could be a problem.eg.lightning
Please answer these

Cmon man these are so big to answer dont u have a book to read from all this

 

[multixamza01]

See this in any aqueous solutions the discharge occurs like in concentrated solutions so if it says aqueous solution of sodium chloride then chlorine discharges like in concentrated solutions remember this as a rule

so if the question doesn't specify whether the solution is dilute or concentrated , we assume it to be concentrated . Is that right?

 

[Tharindu]

Cmon man these are so big to answer dont u have a book to read from all this

Those aren't in the book....if you can pls

 

[syed1995]

so if the question doesn't specify whether the solution is dilute or concentrated , we assume it to be concentrated . Is that right?

No we always assume that it is dilute , we only consider it to be concentrated if it's mentioned that it's concentrated.

 

[syed1995]

I copied this question from the CIE syllabus of 2012. If someone can explain it extensively, I would very much appreciate it

1. state qualitatively and explain the effects of temperature and pressure on the volumes of gases

thanks

 

[syed1995]

Could someone please repeat the solubility chart for me ? that which of them are soluble and which are insoluble ?

i know that All Nitrates are soluble .. what are the others ? i have a test tomorrow so please help .. thanks

Carbonates ?
Halites ?
Oxides And Hydroxides ?
Sulphates ?

are there any which i missed?

 

[legion]

Could someone please repeat the solubility chart for me ? that which of them are soluble and which are insoluble ?

i know that All Nitrates are soluble .. what are the others ? i have a test tomorrow so please help .. thanks

Carbonates ?
Halites ?
Oxides And Hydroxides ?
Sulphates ?

are there any which i missed?

all nitrates are soluble
all carbonates are insoluble except sodium, potassium and ammonium carbonates
all sulfates are soluble except calcium, barium and lead
all chlorides are soluble except lead, silver and mercury
all hyrdoxides of group 1 are soluble. ammonium hydroxide is soluble. calcium hyrdoxide and aluminium are sparingly soluble.
have no idea about halites. sorry

 

[syed1995]

all nitrates are soluble
all carbonates are insoluble except sodium, potassium and ammonium carbonates
all sulfates are soluble except calcium, barium and lead
all chlorides are soluble except lead, silver and mercury
all hyrdoxides of group 1 are soluble. ammonium hydroxide is soluble. calcium hyrdoxide and aluminium are sparingly soluble.
have no idea about halites. sorry

Thanks alot man !! i wasn't sure if i wasn't sure .. just wanted to check

Well halides are compounds of halogens ... so whatever the solubility is for chloride it is for all of them ..

isn't Ca(OH)2 Insoluble ?

Which of the oxides are neutral I know carbon monoxide is one of the neutral oxides ..

and which of them are amphoteric ? Aluminium Oxide , Lead(II)Oxide and Zinc Oxide are the only ones right?

 

[legion]

Thanks alot man !! i wasn't sure if i wasn't sure .. just wanted to check

Well halides are compounds of halogens ... so whatever the solubility is for chloride it is for all of them ..

isn't Ca(OH)2 Insoluble ?

Which of the oxides are neutral I know carbon monoxide is one of the neutral oxides ..

and which of them are amphoteric ? Aluminium Oxide , Lead(II)Oxide and Zinc Oxide are the only ones right?

umm em a gurl =P
hmm chlorine is soluble in water
yeah it is. but sum days ago, sum1 from around here told me k its sparingly soluble
yea you are right
right again.

 

[syed1995]

umm em a gurl =P

oh my bad .. xD

hmm chlorine is soluble in water
yeah it is. but sum days ago, sum1 from around here told me k its sparingly soluble
yea you are right
right again.

thanks alot .. so CO is the only neutral oxide and Al2O3 PbO and ZnO the only amphoteric oxides ?

 

[legion]

oh my bad .. xD



thanks alot .. so CO is the only neutral oxide and Al2O3 PbO and ZnO the only amphoteric oxides ?

yes
try reading these. they contain all these points. i g2g actually. sorry
http://www.xtremepapers.com/revision/gcse/chemistry/acids_bases_and_salts.php