ANSWERING ALL BIO/CHEM PAPER 1 DOUBTS :)

[Sherry Berry]

Feel free to ask for anything
Best of luck to all of you !

 

[SMK]

Chem, p11 q31, hw is de answer b

 

[WhizAly]

Chem, p11 q31, hw is de answer b

Year ?

 

[SMK]

Year ?

2011 oct

 

[WhizAly]

2011 oct

Okay so dry air was added to copper..The dry air is 100
Only the oxygen reacts,so the percentage reacted is 20-21 approximately
At the end the volume of air left is 130 cm3
This 130 cm3 forms about 79-80 (air-oxygen)
So 130----->79
? ------>100
Then the 100 will equal 151 cm3 which rounds to 150 as these rations aren't accurate.

 

[SMK]

2011 MJ v11 Q19

 

[WhizAly]

2011 MJ v11 Q19

Did you get the previous one yet or no ?

 

[SMK]

Did you get the previous one yet or no ?

yup

 

[WhizAly]

2011 MJ v11 Q19

Well coz you don't reply or say Thank You at least..
Anyways,
You should know that barium sulfate is insoluble,and silver chloride is also insoluble.
Insoluble salts don't split up into ions.
Since the solution contains Silver and Barium ions,the only soluble salts possible are silver nitrate and barium nitrate so the nitrate is the anion

 

[SMK]

thank you x2!!!!!sry acually dat tym i jus saw de answer, b4 i cud say thnx, u askd me weder i gt or nt.....

 

[WhizAly]

thank you x2!!!!!sry acually dat tym i jus saw de answer, b4 i cud say thnx, u askd me weder i gt or nt.....

Anytime

 

[TERMINATOR]

Why is SO3 + H20 = H2SO4 not a redox reaction?

 

[thats_me]

Why is SO3 + H20 = H2SO4 not a redox reaction?

As there is no change in oxdation state & electron transfer is not taking place..

 

[Ahmedm96]

june 07 p11 q17

 

[thats_me]

june 07 p11 q17

increase in conc (more collisions as more particles) and temperature (more kinetic energy) increases the rate of reaction causing the graph to be steeper but increasing the size of particles would decrease the surface area as well as the rate of reaction..(causing the graph to be less steeper) so "C" will be the answer

 

[Ahmedm96]

increase in conc (more collisions as more particles) and temperature (more kinetic energy) increases the rate of reaction causing the graph to be steeper but increasing the size of particles would decrease the surface area as well as the rate of reaction..(causing the graph to be less steeper) so "C" will be the answer

Thanks for the fast reply but if concentration is in increased the volume of hydrogen should be higher

 

[thats_me]

Thanks for the fast reply but if concentration is in increased the volume of hydrogen should be higher

It does in some cases ...but here only the speed at which H2 is released is measured...

 

[Ahmedm96]

so what is is the difference if we increased amount of the metal more particles will collide and also more hydrogen should be produced

 

[thats_me]

so what is is the difference if we increased amount of the metal more particles will collide and also more hydrogen should be produced

If ur askin abt the particle size the surface area decreases wen the particle size is increased , Compare a lump and powdered form...powdered i.e small size would react faster to the lump
so increasing size of metal slows down the rate of reaction

 

[Ahmedm96]

thanks now got it

iwas just confused i thought it meant the mass of the metal