Biology; Chemistry; Physics: Post your doubts here!

[captainhyderabad]

it is the question from chemistry matters

 

[scouserlfc]

I don't remember any such reaction but ill see and let u know!

 

[soniashaikh]

can u explain fermentation of antibiotics cloning of plants and whats the difference between cloning and asexual reprodution,they both result in same variation right?

 

[lindalinoo]

hey all .. thanks for the thread its helpfull
i have some questions with investigations
1. describe a food test which might show whether there is more protein to be found in the 'white' or in the 'yolk' of the egg.
i kno tht we test the presence of protein by benedect's solution and the result is violet color .. but the question is DESCRIBE .. so ... ??

another one is how to test for the presence of starch and reducing sugar in honey
one more is in paper 6 oct/nov 2008 page 7 question 2
lol sorry my questions are a lot but i appreciate ur help

 

[princemaazthefinal]

hey all .. thanks for the thread its helpfull
i have some questions with investigations
1. describe a food test which might show whether there is more protein to be found in the 'white' or in the 'yolk' of the egg.
i kno tht we test the presence of protein by benedect's solution and the result is violet color .. but the question is DESCRIBE .. so ... ??

another one is how to test for the presence of starch and reducing sugar in honey
one more is in paper 6 oct/nov 2008 page 7 question 2
lol sorry my questions are a lot but i appreciate ur help

1. firstly protein's detection test is not bendict's test, its biuret test. procedure is 1% albumin + equal amount of dlute sodium hydroxide. Add 1% of copper sulphate solution drop by drop. observation is a violet coluration is formed.
2. reducing sugar is detected through the benedict's test. procedure is warm a mixture of the sugar with some benedict's solution. observation will be solution turns from clear blue to cloudy green, to yellow and finally forms aan orange-red precipitate. starch is detected through the starch test. procedure is to boil starch, placa into test-tube. add a drop of iodine. observation will be a dark blue colourisation being formed.
3. (i) (a) blue (b) blue (c) blue-black
(ii) table 2.1 (a) conlusions reducing sugar/glucose present. (b) protein absent.
(iii) table 2.2 conclusions. (a) no reducing sugar. (b) protein present
(iv) chopping increases surface area?releases cell contents; dissolved in ethanol
water added to complete test; if water added to original ethanol goes milky.

i gave you the main poinnts. I think you can ellaborate it your self.

 

[scouserlfc]

YUP Prince answered it correctly

 

[princemaazthefinal]

^^

 

[lindalinoo]

1. firstly protein's detection test is not bendict's test, its biuret test. procedure is 1% albumin + equal amount of dlute sodium hydroxide. Add 1% of copper sulphate solution drop by drop. observation is a violet coluration is formed.
2. reducing sugar is detected through the benedict's test. procedure is warm a mixture of the sugar with some benedict's solution. observation will be solution turns from clear blue to cloudy green, to yellow and finally forms aan orange-red precipitate. starch is detected through the starch test. procedure is to boil starch, placa into test-tube. add a drop of iodine. observation will be a dark blue colourisation being formed.
3. (i) (a) blue (b) blue (c) blue-black
(ii) table 2.1 (a) conlusions reducing sugar/glucose present. (b) protein absent.
(iii) table 2.2 conclusions. (a) no reducing sugar. (b) protein present
(iv) chopping increases surface area?releases cell contents; dissolved in ethanol
water added to complete test; if water added to original ethanol goes milky.

i gave you the main poinnts. I think you can ellaborate it your self.

i always get confused between biuret and benedict's test :S Allah yestor
thanks alot for ur help i really appreciate it
but hmm the last answer is not the same of what i asked .. its about yeast and hydrogen carbonate
and its question 2 only (a) and (b) answers which i need

 

[scouserlfc]

can u give the paper correctly and the parts as well its a little confusing !

 

[snowbrood]

can anyone provide me worksheets for physics

 

[lindalinoo]

its in paper 6 oct/nov 2008 page 7 question 2 (a) and (b) only ..
hmmm should i write the whole question ?? :S

 

[snowbrood]

can anyone tell me about some observations that we would see if we:
react sulphuric acid or nitic acid or hydrochloric acid or ethanoic acid or lemon juice with sodium carbonate or magnesium ribbon or copper(II)oxide

 

[scouserlfc]

can anyone tell me about some observations that we would see if we:
react sulphuric acid or nitic acid or hydrochloric acid or ethanoic acid or lemon juice with sodium carbonate or magnesium ribbon or copper(II)oxide

See for acid reactions we have fixed products.
1.Acid + Metal Carbonate ---> carbon dioxide + Salt + water
eg, H2SO4 + CaCO3 ---> CaSO4 + CO2 + H2O

2.Acid + Metal ---> Hydrogen + Salt
eg, 2HCl + Mg ---> MgCl2 + H2
3.Acid + Metal Oxide ---> Salt + water.
eg, DO this ur self and lets see if u get it

its in paper 6 oct/nov 2008 page 7 question 2 (a) and (b) only ..
hmmm should i write the whole question ?? :S

Well actually u cud give the link !

See this is what i see !
http://www.xtremepapers.com/CIE/Cambrid ... 8_qp_6.pdf

the prob is that u write part a and b but in the paper it has part 1,2 and these parts have a,b and c parts so please define correctly !

 

[snowbrood]

hey can u suggest me some books for atp of chemistry and physics... i get confused as to what to study for atp paper help me out

 

[soniashaikh]

how can we predict the volume of solution needed to react wth an other solution. there is one question in 2007 may june session papers 6 question no 4 part c
plz solve it?

 

[scouserlfc]

how can we predict the volume of solution needed to react wth an other solution. there is one question in 2007 may june session papers 6 question no 4 part c
plz solve it?

Cant find ur paper !
.

well get the moles of that particular solution and then use ratio of equation to get the mole of that solution,give me a question ill show u !
But please whenever u give a question of a paper,PLEASE write the paper is of which subject and is it P1 or 2s,whether its may/june or Oct/Nov and which question of the paper u want us to check for u !
The best way is to copy link thanks !

hey can u suggest me some books for atp of chemistry and physics... i get confused as to what to study for atp paper help me out

Well no specific books i read or have used FOR Chem just read normal books and READ the following topics as they come most of the time !
1.Mole,(Practice the titration ques in the P4 )
2.Acid bases and salts.
3.SEPARATION and its method

while other topics do come but not everytime !

 

[sweet fairy]

It is K2SO4

 

[HazemAzab]

Re: Biology,Chemistry & Physics Help Available Here !

Need help. What is the chemical formula of potassium sulfate? is it K2SO4 or KSO2?

K2S

 

[SHUBHAsnlnm]

K2SO4

 

[SHUBHAsnlnm]

can you provide the images of the slides that come in the cie exams ie:
trachea
artery
vein
alveoli
root
stem
leaves
xerophytic leaves with trichomes