CHEM AND BIO HELP AND TIPS HERE

[luv3life]

YAYs, jellybeans likes me. xD lol

[Raywin]

Can ethene be cracked ?

Umm.. i dont think so cause ethene is made by cracking alkanes.

[Vin]

O/N 2003 CHEM P1 , Q36!
Which compound is unsaturated and forms a neutral solution in water?

A) CH₂OH-CH--CH-CH₂OH
B) CH₂OH-CH₂-CH₂-CH₂OH
C) CO₂H-CH--CH-CO₂H
D) CO₂H-CH₂-CH₂-CO₂H

i get the unsaturated bit.. but how do you know if it's neutral or not?
doesnt the 'OH' group make it ... acidic? :B hehs, explanation neeeeeded svp, (X
 

answer is A .. why because C doesnt make sense to me ! also OH is alcohol and COOH is acid

[jellybeans]

answer is A .. why because C doesnt make sense to me ! also OH is alcohol and COOH is acid

looooool - uhh but howd you know that alcohols can form neutral solutions in water? 

[Vin]

looooool - uhh but howd you know that alcohols can form neutral solutions in water? 

It is supposed to be neutral .. in fact red litmus paper has an ingredient called "alcohol" .. thts a long story now .. google it if u wanna 

[jellybeans]

It is supposed to be neutral .. in fact red litmus paper has an ingredient called "alcohol" .. thts a long story now .. google it if u wanna 

mkay (:thanks.

[jellybeans]

D: sry another one.. how'd you find out the starting volume??

[holtadit]

D: sry another one.. how'd you find out the starting volume??

20% of X (where x is original vol.) = 30 cm^3

30/0.2 = X = 150 cm^3


We use 20% since oxygen is 20% of air and O2 will have reacted with copper.

[jellybeans]

20% of X (where x is original vol.) = 30 cm^3

30/0.2 = X = 150 cm^3


We use 20% since oxygen is 20% of air and O2 will have reacted with copper.

THAAAAAAANK YOU! 

[Ghost Of Highbury]

D: sry another one.. how'd you find out the starting volume??

Ari answered it, just for the info. Clean air will contain approx. 80% nitrogen and 20% oxygen..

[jellybeans]

Ari answered it, just for the info. Clean air will contain approx. 80% nitrogen and 20% oxygen..

mhmm, thanks

[ambitious94]

Heyy can anyone please explain why the answer is A.

Nov 2004. Chem Ppr 1
33) Which statement explains why iron is used as the catalyst in the manufacture of ammonia?

A) More Ammonia is produced in a given time.
B) The catalyst is unchanged at the end of the reaction.
C) The catalyst neutralises the ammonia.
D) The purity of the Ammonia is improved.

I thght catalyts only speed up the reaction, not increase the yield. Or am I understanding the question incorrectly?
Thanks in advance

[The Golden Girl =D]

Heyy can anyone please explain why the answer is A.

Nov 2004. Chem Ppr 1
33) Which statement explains why iron is used as the catalyst in the manufacture of ammonia?

A) More Ammonia is produced in a given time.
B) The catalyst is unchanged at the end of the reaction.
C) The catalyst neutralises the ammonia.
D) The purity of the Ammonia is improved.

I thght catalyts only speed up the reaction, not increase the yield. Or am I understanding the question incorrectly?
Thanks in advance

when they speed the reaction this means more product produced hence increase the yield

i think it's A idk i solved it but i forgot 

[jellybeans]

when they speed the reaction this means more product produced hence increase the yield

i think it's A idk i solved it but i forgot 

yep its A.

[wstrawberries]

Heyy can anyone please explain why the answer is A.

Nov 2004. Chem Ppr 1
33) Which statement explains why iron is used as the catalyst in the manufacture of ammonia?

A) More Ammonia is produced in a given time.
B) The catalyst is unchanged at the end of the reaction.
C) The catalyst neutralises the ammonia.
D) The purity of the Ammonia is improved.

I thght catalyts only speed up the reaction, not increase the yield. Or am I understanding the question incorrectly?
Thanks in advance

If reaction is speeded up it means that more ammonia can be produced in a set amount of time.Like if you run instead of walk then you naturally cover more distance