Biology; Chemistry; Physics: Post your doubts here!

[syed1995]

Thankss A Loaddd guys syed1995 and rabiafarooq101 !!
i wish i cud hit the like a thousand times! thats a load off! ^__^

no problem dear

 

[Translucent231]

aluminium
argon
iron
nickel
nitrogen
phosphorus
sodium

which of the above is the answer? :

(c) reacts with oxygen to give an acidic oxide,
Nitrogen or phosphorus?? (nothing else i guess?)


WHY DOES THE BLOODY MARK SCHEME SAY THAT ITS ALUMINIUM OXIDE ITS NOT EVEN IN THE BLOODY OPTIONS -_- the question is from s06 qp2 A1

 

[Rimsa]

aluminium
argon
iron
nickel
nitrogen
phosphorus
sodium

which of the above is the answer? :

(c) reacts with oxygen to give an acidic oxide,
Nitrogen or phosphorus?? (nothing else i guess?)


WHY DOES THE BLOODY MARK SCHEME SAY THAT ITS ALUMINIUM OXIDE ITS NOT EVEN IN THE BLOODY OPTIONS -_- the question is from s06 qp2 A1

first option is aluminium -,-

 

[syed1995]

aluminium
argon
iron
nickel
nitrogen
phosphorus
sodium

which of the above is the answer? :

(c) reacts with oxygen to give an acidic oxide,
Nitrogen or phosphorus?? (nothing else i guess?)

WHY DOES THE BLOODY MARK SCHEME SAY THAT ITS ALUMINIUM OXIDE ITS NOT EVEN IN THE BLOODY OPTIONS -_- the question is from s06 qp2 A1

Nitrogen

Al2O3 lol ? that's an amphoteric oxide .. not even acidic :\

 

[rabiafarooq101]

1 mark matters alot@Fallen316

 

[a.abid]

aluminium
argon
iron
nickel
nitrogen
phosphorus
sodium

which of the above is the answer? :

(c) reacts with oxygen to give an acidic oxide,
Nitrogen or phosphorus?? (nothing else i guess?)


WHY DOES THE BLOODY MARK SCHEME SAY THAT ITS ALUMINIUM OXIDE ITS NOT EVEN IN THE BLOODY OPTIONS -_- the question is from s06 qp2 A1

The answer is Aluminium and Nitrogen.Aluminium forms amphoteric oxide which shows the properties of both acids and alkalies.

 

[syed1995]

The answer is Aluminium and Nitrogen.Aluminium forms amphoteric oxide which shows the properties of both acids and alkalies.

But Al203 is NOT an acidic oxide. it acts as an acidic oxide with an alkali to do the neutralization reaction but itself is NOT an acidic oxide.. Nitrogen is the right answer imo.

btw what color would a red litmus show in Al203?

 

[a.abid]

But Al203 is NOT an acidic oxide. it acts as an acidic oxide with an alkali to do the neutralization reaction but itself is NOT an acidic oxide.. Nitrogen is the right answer imo.

btw what color would a red litmus show in Al203?

Yes,its not acidic but it shows the properties of both.So nitrogen will be the correct one.And i searched the answer for ur question on google it says that aluminium oxide is insoluble in water so it doesnt change the litmus clr.

3​

is very INsoluble in water, so it doesn't change lithmus paper color.​

​

Read more​

 

[syed1995]

Yes,its not acidic but it shows the properties of both.So nitrogen will be the correct one.And i searched the answer for ur question on google it says that aluminium oxide is insoluble in water so it doesnt change the litmus clr.

​

is very INsoluble in water, so it doesn't change lithmus paper color.​

​

Read more​

that's a very nice fact to know. didn't knew that it wouldn't change the colour of litmus!

so do we have any amphoteric oxides/substances WHICH are soluble in water .. i want to know whether they would both change the color of a red litmus to blue and a blue litmus to red or not!

 

[daredevil]

aluminium
argon
iron
nickel
nitrogen
phosphorus
sodium

which of the above is the answer? :

(c) reacts with oxygen to give an acidic oxide,
Nitrogen or phosphorus?? (nothing else i guess?)


WHY DOES THE BLOODY MARK SCHEME SAY THAT ITS ALUMINIUM OXIDE ITS NOT EVEN IN THE BLOODY OPTIONS -_- the question is from s06 qp2 A1

uhh... are u sure u saw the ryt answer. just to b sure double check the question and the answer too. if its still true then check the examiner report b/c thats stupid. they shud have given both nitrogen and aluminium oxides in the marking scheme. if they are considering it to b acidic. this is confusing

 

[SALT]

PbO, ZnO,Al2O3...none r soluble in water

 

[rabiafarooq101]

all salts of sodium potassium and ammonium are soluble always rem this

 

[ayeshaK]

http://www.xtremepapers.com/papers/...al O Level/Chemistry (5070)/5070_w08_qp_1.pdf
Mcq no 19 and 22

 

[syed1995]

http://www.xtremepapers.com/papers/CIE/Cambridge International O Level/Chemistry (5070)/5070_w08_qp_1.pdf
Mcq no 19 and 22

19 >B ? 40 Tonnes .. as NH3 will be divided equally in both the parts and then compare the moles.

22 > B?

 

[rabiafarooq101]

http://www.xtremepapers.com/papers/CIE/Cambridge International O Level/Chemistry (5070)/5070_w08_qp_1.pdf
Mcq no 19 and 22

19 wala is 40 dont know how but 22 wala notice curve 2 it is more steep and has a larger height this shows either conc or number of moles is alterd only one option shows this toh it is b

 

[ayeshaK]

19 wala is 40 dont know how but 22 wala notice curve 2 it is more steep and has a larger height this shows either conc or number of moles is alterd only one ption shows this toh it is b

19 >B ? 40 Tonnes .. as NH3 will be divided equally in both the parts and then compare the moles.

22 > B?

Ahan thnku

 

[rabiafarooq101]

19 >B ? 40 Tonnes .. as NH3 will be divided equally in both the parts and then compare the moles.

22 > B?

mujhay be yeh 19 wala explain karo

 

[rabiafarooq101]

Ahan thnku

no problem

 

[Tharindu]

Can acidic OXIDES be used to neutralize bases...and btw wats the equation for this

 

[syed1995]

mujhay be yeh 19 wala explain karo

rabia, yaar meri explanations sux .. anyways i will try

dekho NH3 do jagah use horaha hai ..


Stage 1 NH3 + 2O2 → HNO3 + H2O
Stage 2 HNO3 + NH3 → NH4NO3

tu jitna bhi mass hai ussay hum equally distribute kar deingay .. dono stages ko .. so 17 tha na ? 8.5 ooper walay ko aur 8.5 neechay walay ko ..

Moles=mass/mr
8.5/17=0.5= Moles of NH3 in Reaction one.

ab compare karo .. aik mole NH3 ka Aik mole bna raha NH4NO3 ka.

so 0.5 moles will make 0.5 moles.

Mass Of NH4NO3
Mass=Molar Mass*Number of Moles
Mass=80*0.5
Mass=40 Tonnes