Physics, Chemistry and Biology: Post your doubts here!

[Phoenix Blood]

Help me with the (d) part...

 

[Phoenix Blood]

Why do we make it all "two"? (2Ag and all...) Isn't what i have written in blue correct?

 

[rida.12.!!]

Did you refer to the mark scheme?

no i can't get the marking scheme!!

 

[Phoenix Blood]

no i can't get the marking scheme!!

Question paper number?

Oxides of Nitrogen are formed when
Oxygen from the air
and Nitrogen from car exhausts , etc
react at high temperatures

Oxides of Sulphur are formed
when sulphur released from industries and burning of fossil fuels like coal
react with the oxygen in air.

 

[rida.12.!!]

Question paper number?

Oxides of Nitrogen are formed when
Oxygen from the air
and Nitrogen from car exhausts , etc
react at high temperatures

Oxides of Sulphur are formed
when sulphur released from industries and burning of fossil fuels like coal
react with the oxygen in air.

I HAVE NO IDEA ONE OF MY FRIENDS GAVE ME THESE QUESTIONS
I GUESS ITS 2013 CUZ I'VE SEARCHED UP TILL 2012 AND I DIDN'T GET THESE QUESTIONS

 

[rida.12.!!]

AS SALAM O ALAIKUM
HI!!!!!!
GUYS SOME CHEMISTRY DOUBTS:-
HOW ARE OXIDES OF NITROGEN FORMED??
HOW IS SULFUR DIOXIDE FORMED??
DEFINE THE AVOGADRO CONSTANT??
AND SOME OTHER QUESTIONS IN THE FILE I ATTACHED!!
THANK YOU!!

 

[Awesome12]

Help me with the (d) part...

Reduction
As the reaction is
GeCl2 + Cl2 ------> GeCl4

the oxidation state of Cl2 is 0, and the oxidation state of Clorine in the GeCl4 is -1.
Thus a decrease in the oxidation state is reduction

 

[Awesome12]

Why do we make it all "two"? (2Ag and all...) Isn't what i have written in blue correct?

First of all write the reaction
Zn(s) + AgNO3 (aq) -----> Zn(NO3)2 (aq) + Ag(s)
Balance the equation

Zn(s) + 2AgNO3 (aq) -----> Zn(NO3)2 (aq) + 2Ag(s)

Zn + 2Ag+1 + 2NO3-1 ---------> Zn+2 + 2NO3-1 + 2Ag

Cut the nitrate ions to get

Zn + 2 Ag+1 -------> Zn+2 + 2Ag

 

[Phoenix Blood]

Reduction
As the reaction is
GeCl2 + Cl2 ------> GeCl4

the oxidation state of Cl2 is 0, and the oxidation state of Clorine in the GeCl4 is -1.
Thus a decrease in the oxidation state is reduction

Thanks

 

[Phoenix Blood]

Can you explain this?

 

[Awesome12]

Can you explain this?

(i) The high potential is always connected to the Y Plates
(ii) Thats pretty simple
(iii) Since the spot is only moving up and down, it is clear that the Y-Gain is turned on. The Time base is used to control the X-Plates that move the spot horizontally. In this case, the spot is not moving horizontally, which is why the time base is turned off or is at o

 

[rida.12.!!]

Awesome12
SOME CHEMISTRY DOUBTS:-
HOW ARE OXIDES OF NITROGEN FORMED??
HOW IS SULFUR DIOXIDE FORMED??
DEFINE THE AVOGADRO CONSTANT??
AND SOME OTHER QUESTIONS IN THE FILE I ATTACHED!!
THANK YOU!!

 

[rida.12.!!]

Awesome12
SOME CHEMISTRY DOUBTS:-
HOW ARE OXIDES OF NITROGEN FORMED??
HOW IS SULFUR DIOXIDE FORMED??
DEFINE THE AVOGADRO CONSTANT??
AND SOME OTHER QUESTIONS IN THE FILE I ATTACHED!!
THANK YOU!!

 

[Awesome12]

Awesome12
SOME CHEMISTRY DOUBTS:-
HOW ARE OXIDES OF NITROGEN FORMED??
HOW IS SULFUR DIOXIDE FORMED??
DEFINE THE AVOGADRO CONSTANT??
AND SOME OTHER QUESTIONS IN THE FILE I ATTACHED!!
THANK YOU!!

(a) During lightning activity, Nitrogen in the atmosphere combines with O2 to form NO2. Also in the catalytic convertors of cars, NO (nitrogen monoxide) is formed
(b) SO2 can be made by heating Sulphur in the presence of air. At 114 degrees, it becomes red, and at 444 it boils and catches fire burning with a blue flame. SO3 can be formed by reacting SO2 with air at 450 degrees, 60 atmospheres, and in the presence of a vandanium(V) catalyst
(c) It related to the number of moles in a substance

 

[rida.12.!!]

thx , but i guess there were some more questions as well

 

[rida.12.!!]

 

[princess sofia]

cn any1 plz ans thx question
State da factors dat affect the rate of mutation?
thnx

 

[Starry4]

Assalam-o-Alaikum.
Post your Physics, Chemistry and Biology doubts in here and members, along with me will try their best to help you out.

I'm struggling with Physics Olevel June 2011 Paper 31, I mean seriously the 2011 students must have had a tough year

 

[shoaib672002]

Plz solve all and with diagrams

 

[dubi2pro]

the 24th one.

How is it 3.0 MOL/DM^3?