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  1. sidbloom1995

    Chemistry: Post your doubts here!

    Q3. e first write a balanced equation of reaction between CH3CO2H and NaOH CH3CO2H + NaOH ----------> CH3CO2-Na+ + H2O we have 0.25 mol/dm3 of CH3CO2H and 0.1 mol/dm3 of NaOH since the buffer is of acid and i's salt, all of the alkali will be converted to salt and the acid will be in excess...
  2. sidbloom1995

    Chemistry: Post your doubts here!

    can you post the paper no.?
  3. sidbloom1995

    Chemistry: Post your doubts here!

    i will first explain the wrong answers! D = because it is a tertiary aldehyde so it wont react! A = the basic CH3CO2CH3 structure is being disturbed, when reacting only the functional groups will react B = it could have been the answer but in our question, the molecule of CH3CO2CH3 was ionised...
  4. sidbloom1995

    Chemistry: Post your doubts here!

    Q3. we add the first and second ionisation energies of Al: 1820 + 577 = 2397 kJ/mol now we add the the ionisation energies of each element given and the one that add up to 2397 will be our answer! so when we add the 1st and 2nd ionisation energy of Co we get: 1640 + 757 = 2397 kJ/mol so our ans...
  5. sidbloom1995

    Chemistry: Post your doubts here!

    nucleophile is a group with lone pairs of electrons and OH- is a nucleophile! we also know that during this reaction the OH will displace the Br from bromoehtane so it will most likely be by the SN (nucleophilic substitution), and as the name suggest, in this one nucleophile displaces the other...
  6. sidbloom1995

    Chemistry: Post your doubts here!

    i like the idea, we can do something like that here by announcing the date and doing all of it one at time!
  7. sidbloom1995

    Chemistry: Post your doubts here!

    well about how should we know this, they are all general equations and you sort of have to remember them! with phosphorus and iodine, there will be replacement of OH by I with conc. H2SO4, there will be elimination of water, for that we will take the -OH group from one carbon and the -H from the...
  8. sidbloom1995

    Chemistry: Post your doubts here!

    there could be a lot of reasons! 1. like when you do when finish one tit-ration, you dont rinse the flask thoroughly or you dont dry it and add the next contents in it just like that 2. maybe you observe the color change for some as dark and for some as light! 3. maybe you pour the starting...
  9. sidbloom1995

    Chemistry: Post your doubts here!

    when solving past papers first solve the question and write down your answers and then just compare the final answers and you wont be mislead or confused by the mark scheme!
  10. sidbloom1995

    Chemistry: Post your doubts here!

    the answer is simple! the MS just went round about it!! we already have our equation for H2S with O2 2H2S + 3O2 ---------> 2H2O + 2SO2 we first find the moles of H2S n of H2S = [8.65/34.1] = 0.254 mol use the ratio relation from the equation 2 moles of H2S and 3 moles of O2 are uused H2S ...
  11. sidbloom1995

    Chemistry: Post your doubts here!

    one moere thing i would like to add is that in the MS it said to ignore the sign and the flow is from right to left!! this means that the Left is (+) and Right is (-), it's just that when they give us a diagram like that they follow there equation of [Ecell = Er - El] overall this suggest that...
  12. sidbloom1995

    Chemistry: Post your doubts here!

    i got the answer but my method is completelyyyyyyyyyyyyyyyyy different from the MS!! so i dont think i will be able to help you with question 2(c) ~sorry~ T_T as for the equation i was able to do it, but the next part i was not able to! you can check the ans. in the pic i didnt understand the...
  13. sidbloom1995

    Chemistry: Post your doubts here!

    i see sorry, didnt get u before >< as for the last part im confused so i cant answer you!
  14. sidbloom1995

    Chemistry: Post your doubts here!

    oh ok! that questuion was asked by someone else and a specific part so i didnt do the pKa part before! (i) the Ka expression Ka = [H+][R-]/[HR]............the R is the rest of the group or structure!....in the MS they wrote A but that was confusing because the previous question asked for a...
  15. sidbloom1995

    Chemistry: Post your doubts here!

    i checked your question again! are you asking about the smooth curves? just as the names suggest they are curves that are smooth, we usually use then in reaction kinetics most often! was this what you were asking?
  16. sidbloom1995

    Chemistry: Post your doubts here!

    which one?
  17. sidbloom1995

    Chemistry: Post your doubts here!

    ok check it in the pictures!
  18. sidbloom1995

    Chemistry: Post your doubts here!

    i was able to understand it but i wasnt able to solve it (the third part) :p ~sorry; was not much help~ (i) they asked us the pH, for that we will dissociate the acid and form an equation CH3CH2COOH -----------> CH3CH2COO- + H+ we use this equation in in the formula...
  19. sidbloom1995

    Chemistry: Post your doubts here!

    can you please post the MS. i need to confirm my ans. before ans. to u!!
  20. sidbloom1995

    Chemistry: Post your doubts here!

    the question states that it is a dibasic acid, that means that there are two -COOH groups present at it's two ends you first find the no. of moles of the NaOH, which in this case is 1.2 x 10^-3 then since you know that there are two acidic groups then that mean that we will need 2 molecules of...
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