Biology; Chemistry; Physics: Post your doubts here!

[Tharindu]

Can anyone explain question 6...may June 2011...chemistry....paper 42

 

[asd]

is light one of the condition for seed to germinate?

No, but after germination it is essential ! Here, seeds that germinated in dark, the new shoots had no light and therefore most of them would develop pale green leaves (less light-green light reflected less-pale green colour).

 

[luckywang]

Can anyone explain question 6...may June 2011...chemistry....paper 42

link pls? lazy go find...

 

[SalmanPakRocks]

Can anyone explain question 6...may June 2011...chemistry....paper 42

This has been already discussed before. The Answer is D. Please scroll back few post and you'll find it's explanation.

 

[Tharindu]

link pls? lazy go find...

http://www.xtremepapers.com/papers/...l O Level/Chemistry (5070)/5070_s10_qp_42.pdf

 

[luckywang]

No, but after germination it is essential ! Here, seeds that germinated in dark, the new shoots had no light and therefore most of them would develop pale green leaves (less light-green light reflected less-pale green colour).

i still not understand... less light will develop a more green leaf? just like the one in our atp?

 

[asd]

i still not understand... less light will develop a more green leaf? just like the one in our atp?

NOOO, less light will result in less green leaves! In our atp, it was a specific type of leaf. In general, leaves need light to be green.

 

[luckywang]

http://www.xtremepapers.com/papers/CIE/Cambridge International O Level/Chemistry (5070)/5070_s10_qp_42.pdf

answer not C? coz D is too concentrate? C have double the mole so the product is double too?

 

[SalmanPakRocks]

answer not C? coz D is too concentrate? C have double the mole so the product is double too?

It's D

 

[asd]

This has been already discussed before. The Answer is D. Please scroll back few post and you'll find it's explanation.

Yea, but as ashiqbal said, why would zinc in powdered form not affect the rate?

 

[luckywang]

NOOO, less light will result in less green leaves! In our atp, it was a specific type of leaf. In general, leaves need light to be green.

erm..... still quite confusing... so the answer is? i try to figure it out....

 

[Spidey21]

i still not understand... less light will develop a more green leaf? just like the one in our atp?

less light will cause more Chlorophyll to be produced...(more chloroplast)
and chlorophyll has what colour??? GREEN!!!
so which plant will be more green? the one with more chloroplasts (in the shade) or the one with less (light)

 

[SalmanPakRocks]

Yea, but as ashiqbal said, why would zinc in powdered form not affect the rate?

That's due to the concentration, sadly we don't even have any comments on this in examiner report, Can you guys wait? I'll ask my teacher.

 

[luckywang]

Yea, but as ashiqbal said, why would zinc in powdered form not affect the rate?

powder form? is the question mentioned powder form?

 

[SalmanPakRocks]

powder form? is the question mentioned powder form?

Yes!

 

[Tharindu]

Omg....I did the calculation for min mark for A*....it's very hard

 

[asd]

That's due to the concentration, sadly we don't even have any comments on this in examiner report, Can you guys wait? I'll ask my teacher.

Maybe a contradictory question

 

[luckywang]

less light will cause more Chlorophyll to be produced...(more chloroplast)
and chlorophyll has what colour??? GREEN!!!
so which plant will be more green? the one with more chloroplasts (in the shade) or the one with less (light)

but asd said leaves expose to less light result light green leaf.... and now u said leaves expose to less light have darker colour.... omg... more confused...

 

[luckywang]

Yes!

6 A student added 10.0 cm3
of 0.100 mol/dm3
hydrochloric acid to an excess of zinc. The
volume of hydrogen produced was recorded at intervals until no more gas was produced.
This was experiment P.
The experiment was repeated with a different acid solution, again using an excess of zinc.
This was experiment Q.
The graphs of the two experiments are shown on the grid below.
volume of
hydrogen
/ cm3
time/ s
P
Q
Which acid solution would give the graph for experiment Q?
(a) 10 cm3
of 0.050 mol/dm3
hydrochloric acid
(b) 10 cm3
of 0.200 mol/dm3
hydrochloric acid
(c) 20 cm3
of 0.100 mol/dm3
hydrochloric acid
(d) 20 cm3
of 0.200 mol/dm3
hydrochloric acid


i cannot find anything about powder form in this question?

 

[asd]

but asd said leaves expose to less light result light green leaf.... and now u said leaves expose to less light have darker colour.... omg... more confused...

Spidey21 The question in our atp was related to a specific type of leaves, so light had different effects on it. If i'm not wrong...