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Chemistry MCQ thread...
nope, it would react with potassium manganate not potassium dichromate -
Mathematics: Post your doubts here!
can someone please explain to me the first question in this paper ? http://www.xtremepapers.com/papers/CIE/Cambridge%20International%20A%20and%20AS%20Level/Mathematics%20(9709)/9709_s09_qp_3.pdf -
Chemistry: Post your doubts here!
i dont know about ur sir but i always studied it that "the enthaply change (ΔH) is equal to the enthalpy change of product - the enthalpy change of reactant" that's how i had been taught bro! -
CHEMISTRY PAPER 1
ok this question took me some time to get it but now i got it ! so lemme explain it for u.. ok so you see this is the hess's cycle that i drew from there we can see that the, ΔH of formation of CO2 = -283 ΔH of formation of H2O = -268 and we also need the enthalpy change when we change the... -
Chemistry: Post your doubts here!
need explanation to this question isn't it supposed to be -176 because.. ΔHf = (2(38) + 2(-214) ) / 2 really confused :( -
Chemistry: Post your doubts here!
you know that ΔH = ΔHp - ΔHr so ΔH = (4NO + 6H20 ) - ( 4NH3) ΔH = (4(90.3) + 6(-241.8) ) - (4(-46.1) ΔH = -905.2 therefore the answer is C ! knowing the definition of the enthalpy change of formation will help u a lot in this question. i hope i have helped u though! -
Chemistry: Post your doubts here!
okay here is the explanation to ur question.. you must know that any bond forming is an exothermic reaction and is (-) and any bond breakin reaction is an endothermic reactiona and (+) so we have one X-X bond formed and 6 X-H and that made a total exothermic energy of = -2775 kj/mol and if u... -
Mathematics: Post your doubts here!
yeah i tried to but its failing..can u do it please ? -
Mathematics: Post your doubts here!
duuuhhh -_- i know that but how can i integrate that ? i know we have to use integration by parts but it is not working for me ! -
Mathematics: Post your doubts here!
how to solve question 9 ( ii) http://www.xtremepapers.com/papers/CIE/Cambridge%20International%20A%20and%20AS%20Level/Mathematics%20(9709)/9709_s08_qp_3.pdf -
Mathematics: Post your doubts here!
man u serious ? u r an A level student and u dont know how to integrate (x^2-2x)(1/x).. (x^2-2x)/x = x(x-2)/x cancel the x's!! then u will have x-2 and thats pretty easy to integrate eh..i guess u were a bit confused right :P ? -
Chemistry: Post your doubts here!
for question 21, the answer can be easily found if u understand the definition of a chiral atom.. here in this question the carbon atom should be attached to four other groups so that it can be called a chiral carbon. in A it is chiral cuz u can see the carbon is atom attached to four different... -
Chemistry: Post your doubts here!
ok here the the explanation of the answers, for question 16, in the question it is stated that the compound is decomposed and the solid left is reacted with hydrochloric acid and formed carbon dioxide(Vigorous effervescence).. if we took the first option CaCO3 and we decomposed it calcium... -
Chemistry: Post your doubts here!
thanks a lot man..makes more since now! -
Mathematics: Post your doubts here!
they already said leave the answer in surds..so when u do the equation x= -b ±√(b^2-4ac) / 2a u will end up with x =1/4 (-20 + √40) or 1/4(-20-√40) u can simplify it..did u get it now ? -
Chemistry: Post your doubts here!
can u explain question 14 in more detailed pls ? :(:( -
Which is Easier Mechanics 1 or Statistics 1 for AS Level Maths?
what do you wanna be after u finish high school? -
EDEXCEL AS AND CIE A2
go read more about it and u will know this is not allowed -
Mathematics: Post your doubts here!
i heard from many of my friends and from friends who actually did edexcel they say that maths edexcel is easier by lots! they say cie math is so complicated while edexcel maths is simple ! but personally i do not know! -
EDEXCEL AS AND CIE A2
TCHS u didn't get her. she was talking about doing the SAME subject she did for edexcel AS as CIE A2 which is impossible to do if u started with edexcel for a specific subject for AS then u have to continue with it in A2 edexcel too but u can take a mixture of edexcel and CIE subjects at the...