Physics, Chemistry and Biology: Post your doubts here!

[NIM]

its A

how????
all plants cant move from there position rite!!!

 

[thats_me]

how????
all plants cant move from there position rite!!!

No they can, like not move frm one place to another but they can move like phototropism , geotropism they grow towards the light or gravity as in the movement is not rapid , some plants even move wen u touch them..

 

[NIM]

No they can, like not move frm one place to another but they can move like phototropism , geotropism they grow towards the light or gravity as in the movement is not rapid , some plants even move wen u touch them..

can u plz giv me an example of a plant which can move if touched...
thnx in advance!!!

 

[thats_me]

can u plz giv me an example of a plant which can move if touched...
thnx in advance!!!

As far as i knw there is one called tickle me plant but here http://en.wikipedia.org/wiki/Mimosa_pudica

 

[NIM]

As far as i knw there is one called tickle me plant but here http://en.wikipedia.org/wiki/Mimosa_pudica

thnx dude u really helped me

 

[thats_me]

thnx dude u really helped me

ur welcum

 

[Abu mota]

are u talking about paper 1?

Yes paper 1 chemistry

 

[Abu mota]

For 1999 i couldn't find p1 :S
n 2002 :The question is which would NOT remove the colour of bromine?
The colour would NOT change wen bromine CANNOT displaces any of these halides now bromine CANNOT displace itself
so 1 will be KBr and bromine CANNOT diplace chlorine as it is higher in the reactivity series so 2nd in KCl
the ans will be A KCl and KBr

Tyvm, check the link and you will find 1999

 

[thats_me]

Tyvm, check the link and you will find 1999

Ohk yea found it..
21 : As potassium is very reactive potassium metal cannot be used but hydroxide and carbonate can so i think i'll be C
35 : lime is used in makin cement so i think i'll be B

 

[Abu mota]

Ohk yea found it..
21 : As potassium is very reactive potassium metal cannot be used but hydroxide and carbonate can so i think i'll be C
35 : lime is used in makin cement so i think i'll be B

why being reactive doesnt allow it to be used?

 

[thats_me]

why being reactive doesnt allow it to be used?

As the reaction is extremely exothermic

 

[Abu mota]

As the reaction is extremely exothermic

oh ok tyvm

 

[Ahmed Khider]

Hey guys in chemistry when do we use a pippete, a burette and a measuring cylinder to measure volumes. Im asking this question becoz many questions including those 3 come in paper 1.

 

[thats_me]

the most accurate is burette then pipette and then measuring cylinder ..

Hey guys in chemistry when do we use a pippete, a burette and a measuring cylinder to measure volumes. Im asking this question becoz many questions including those 3 come in paper 1.

 

[sweetsis]

Hey guys in chemistry when do we use a pippete, a burette and a measuring cylinder to measure volumes. Im asking this question becoz many questions including those 3 come in paper 1.

a pipette measures fixed volumes like 25cm^3 ...a burette measures volumes to one decimal place and so is used for experiments like titration where accuracy is required ,while measuring cylinder is used when precision and accuracy is not required....

 

[Abu mota]

hi,
i have a couple of questions in oct/nov 1998
Q.4
Q.21
Q.11
tyvm and plz help
http://www.freeexampapers.com/past_papers.php?l=Past_Papers/IGCSE/Chemistry/CIE/1993-2003/ here is the link again

 

[Ahmed Khider]

a pipette measures fixed volumes like 25cm^3 ...a burette measures volumes to one decimal place and so is used for experiments like titration where accuracy is required ,while measuring cylinder is used when precision and accuracy is not required....

Thx alottttttttt

 

[Ahmed Khider]

the most accurate is burette then pipette and then measuring cylinder ..

Thx alott

 

[xxxt]

Hey guys in chemistry when do we use a pippete, a burette and a measuring cylinder to measure volumes. Im asking this question becoz many questions including those 3 come in paper 1.

pipate is for fixed volume eg 25cm3
burette is for accurate measurement of a certain small volume in ml liike the one used in titration
measuring cylinder is for bigger volumes depending on its capacity.

 

[Abu mota]

hi,
i have a couple of questions in oct/nov 1998
Q.4
Q.21
Q.11
tyvm and plz help
http://www.freeexampapers.com/past_papers.php?l=Past_Papers/IGCSE/Chemistry/CIE/1993-2003/ here is the link again

anyone?