I appreciate it but thats not the right answer...all kinds i think
some reactions such as enthalpy change from the combustion of glucose can be obtained just by using a calorimeter so Hess's Law is not needed...
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I appreciate it but thats not the right answer...all kinds i think
look Ca2+ needs 2(-1) to balance it out ryt??yes it is ethanoic acid but how do u get the empirical formula that they have given to us ?
i didn't say we definitely need Hess for all the enthalpy changes but it is always possible to solve these questions with Hess if nothing else works.I appreciate it but thats not the right answer...
some reactions such as enthalpy change from the combustion of glucose can be obtained just by using a calorimeter so Hess's Law is not needed...
look Ca2+ needs 2(-1) to balance it out ryt??
if we take two of ethanoic acids it gives us C4H6O4
if we take 2 butanedoic acid it gives us something with eight C and with mmethypropanadoic acid is the same case...
only ethanoic acid gives the correct formula. remember to use 2 acids not 1 to balance out the one Ca.
anyone?
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_w10_qp_12.pdf
have been doing question 22 for so long..but im not getting 16
can someone plsss do it
The product gets oxidized.. both the C=C bonds will be broken... CH2 forms CO2 + H2O .. .. CHR forms aldehyde .. and CRR` forms Ketone..
So final product becomes ..
Answer is 3.
Y = Products formed with reaction with CN + acid .. = CH3+CH(OH)COOH
Z = Product formed after oxidation is = CH3CH2COOH ..
The only difference in both is that Y has one more O then Z. so the difference in mass is 16.
i dont get this one
thanks for ur try bro but i asked for november 2009 which u can see on my post please help me at that
thanks
Q1's answer is C. from the data u can infer that 50 cm3 of O2 was used to burn 10cm3 of hydrocarbon (CxHy)
make up an equation for the unknown hydrocarbon for ur aid and u'll c that 1 mol of CxHy requires 5 moles of O2 to produce 3 mol of CO2. 6 O go into the CO2 and the remaining 4 (from 5 O2) go to the H2O which means that 4 H2O molecules were formed. so we have 8 H and 3 C thus the ansewr.
Q2's answer is bcz 2 mol of NaN3 make 3 mol of N2 which means 1 mol makes 1.5 mol of N2 directly. then the Na produced also makes N2.
wth 2 mol of NaN3 we get 2 mol of Na so with 1 mol we get 1 mol of Na.
10 mol of Na produce 1 mol of N2 so 1 mol produces 0.1 mol
so total N2 produced is 1.5 + 0.6 = 1.6mol
i don't get q10 so if u get an answer for that tag me ^_^
i dont get this one
That was the paper which you linked :\
D?soory bro i just realized it was my mistake
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_w09_qp_11.pdf
of this paper can u please solve number-28
thanks alot
3 is correct as it will form a diester try making a diester and you will see that it will form the co,pound with the formulaeanother urgent doubt please help
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_w10_qp_12.pdf
number-38
i know tht 2 is correct but cant understant how 3 is correct as well?
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