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Physics, Chemistry and Biology: Post your doubts here!

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when they ask for a straight line graph do u draw a line between each point using a ruler? cuz then sometimes it doesnt appear as a straight line but crooked instead.
 
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when they ask for a straight line graph do u draw a line between each point using a ruler? cuz then sometimes it doesnt appear as a straight line but crooked instead.
It depends on graphs, and u shud never draw a graph with a ruler unless the gradient is constant .. :)
 
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CHEMISTRY HELP
Hey, can anybody teach me how to draw structural formula's of polymers ?? please it is important =[
 
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CHEMISTRY HELP
Hey, can anybody teach me how to draw structural formula's of polymers ?? please it is important =[


there are types of polymers ( natural and condensation, synthetic )
Synthetic:
( polyethene, polychloroethene, are important)

e.g monomer of polyethene is simple ethene ( CH2=CH2 ) so extend it and remove the double covalant chain like this ( CH2-CH2...........so on depends on how much question demand )



Have a look at this ... hope it will help.IMAG0444.jpgIMAG0444.jpgIMAG0444.jpgIMAG0444.jpgIMAG0444.jpgIMAG0444.jpgIMAG0445.jpg IMAG0444.jpg
 

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there are types of polymers ( natural and condensation, synthetic )
Synthetic:
( polyethene, polychloroethene, are important)

e.g monomer of polyethene is simple ethene ( CH2=CH2 ) so extend it and remove the double covalant chain like this ( CH2-CH2...........so on depends on how much question demand )



Have a look at this ... hope it will help.View attachment 10358View attachment 10358View attachment 10358View attachment 10358View attachment 10358View attachment 10358View attachment 10359 View attachment 10358
heyyyyy thanks al00ot !! that reaaaly helped me, thanks soooo much =] !!!
 
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Question 1 (c) u have to simply find the area under the graph, that is 1/2*b*h , so 0.5*5*10.5 = 26.25
Question 8 (c) Decreases because resistance increases causing the current to decrese =)
Question 8 (d) 4 ohms, because the resistance will double ..
Alpha goes into paper because it gets absorbed , charge, alpha carries a +2 charge,
Beta goes out of paper because it can pass through paper (in tiny ammount) charge always -1 (electrons)
Gamma nothng happns, and no charge, never it carries charge,

Hope i helped =]
thank you soo much dear but still i have some doubt! in question 1 (c) the height is 12 i think :/ thn 0.5*12*5...pls make it clear ;/
and alpha can go left and righ also right or only into the paper? and which hand rule will we have to use?
 
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In chem p6, when v draw the graph, how do v noe whether 2 draw freehand or with a scale? sby plz clarify
 
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In chem p6, when v draw the graph, how do v noe whether 2 draw freehand or with a scale? sby plz clarify
no they tell u in the question... smooth curve is free hand but the thingis im not sure with the straight line graph thing. Gradient are almost never constant in chem.
 
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Guys please help, in Physics May June 2010 paper 31, I can't understand questions 11(b) and 5(d). Anyone please help? :)
 
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for the first one !! u dont need to know ! just write ... compression , rerefaction,compression , rerefaction,compression , rerefaction

q 4 a (i) put the hot juction in what ever to measure n read the voltmeter reading , convert the meter reading to tempreture
q 9 a(ii) use equation v2/v1=n2/n1
 
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I have two Chemistry P6 doubts and I'd really appreciate any effort to help me out:

1) http://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Chemistry (0620)/0620_w11_qp_62.pdf
When you use excess lumps of zinc instead of powder, does the final volume of gas produced decrease? The mark scheme says: "Sketch curve to right and below original". Even the examiner report mentions: "The sketch for the lumps curve in (ii) often went too high and joined the original graph".

2) I've noticed that in some questions, increasing the concentration of a reactant causes the final volume of gas produced to increase. In other questions, however, increasing the concentration increases the reaction rate but the final volume of gas produced remains the same. How will I know the difference?

EDIT: Never mind. I got my doubts clarified.
 
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