Chemistey Doubts

[shan5674]

hw do u solve q)5)b) on mj 09
this is d link fr d paper:- http://www.xtremepapers.me/CIE/Cambridg ... 9_qp_3.pdf

pls help i really dont understand this question..

viewtopic.php?f=24&t=9375&start=10

check this out

2nd page 1st post

 

[ajmanutd]

hw do u solve q)5)b) on mj 09
this is d link fr d paper:- http://www.xtremepapers.me/CIE/Cambridg ... 9_qp_3.pdf

pls help i really dont understand this question..

viewtopic.php?f=24&t=9375&start=10

check this out

2nd page 1st post

than i gt it nw..

 

[hredoymohammad]

m/j 2011 p-61 no 5 b ii) ....y not the answer is lilac?

 

[ktc]

m/j 2011 p-61 no 5 b ii) ....y not the answer is lilac?

The color of [solid] Potassium Iodide *crystals* is white.

The color of [aqueous] Potassium Iodide *solution* is colorless.

For the answer b ii) => when you place potassium iodide solution in a dry watch glass, and touch it with a lighted splint, the lighted splint gets extinguished.

 

[GetSomeLife]

m/j 2011 p-61 no 5 b ii) ....y not the answer is lilac?

5 a ii) u dont hav to mention nythin bout SOLID since its clearly mentioned LIQUID potassium iodide...so in order to get full 2 marks u hav to write:

COLOURLESS with NO SMELL...

5 b ii) The lighted splint iz extinguished...

 

[hredoymohammad]

y it is extinguised? wats the reason?

 

[ktc]

y it is extinguised? wats the reason?

Well, Potassium Iodide solution is a reducing agent

It takes away the oxygen from the ‘fire’ [lighted splint] – which is why the lighted splint gets extinguished [the fire dies out]

 

[ab26ab]

Q1.what mass of gas,of molecular mass 36.5 is present in 4.8 dm3 of the gas ? (1 mol gas =24 dm3 at room temp./press.)

Q2. given the reaction between nitrogen and hydrogen to form ammonia :
N2(g) + 3H2(g) ==> 2NH3(g)
what volume of ammonia in dm3 is formed if 40dm3 of nitrogen reacts ?

 

[Iridescent]

Q1.what mass of gas,of molecular mass 36.5 is present in 4.8 dm3 of the gas ? (1 mol gas =24 dm3 at room temp./press.)

Q2. given the reaction between nitrogen and hydrogen to form ammonia :
N2(g) + 3H2(g) ==> 2NH3(g)
what volume of ammonia in dm3 is formed if 40dm3 of nitrogen reacts ?

Ans1: (36.5)*(4.8)/(24)
=7.3g.