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  1. Metanoia

    Chemistry: Post your doubts here!

    The equation: moles of water formed x heat of neutralization = mass of solution x heat capacity of solution x temperature change Can be used with different volumes, concentrations and reactants, it is not necessary that the molar ratio of reactant to water is 1:1. For different concentrations...
  2. Metanoia

    Chemistry: Post your doubts here!

    Hmm.. why wouldn't you want to make use of the supplied info that reactants are brine (NaOH + H2O) and products are NaOH, H2 and Cl2? If you were to create your own cathode /anode equations, what did you end up with?
  3. Metanoia

    Chemistry: Post your doubts here!

    Generally , heat released during neutralization = heat used to raise temperature of solution moles of water formed x heat of neutralization = mass of solution x heat capacity of solution x temperature change From expt 1, (0.05) x heat of neutralization = 100 x heat capacity of solution x...
  4. Metanoia

    Chemistry: Post your doubts here!

    Form equation first 2NaCl + 2H2O --> 2NaOH + Cl2 + H2 Then its a simple mole calculation question involving 58.5 kg of NaCl.
  5. Metanoia

    Chemistry: Post your doubts here!

    Temperature increase (due to heat of neutralization) should still be 6 degree celsius. Expt 1: 50cm3 of acid + 50 cm3 of alkali (0.05 mol of water formed, releasing heat) Expt 2: 100cm3 of acid + 100 cm3 of alkali (0.1 mol of water formed, releasing heat) Basically you are generating 2 twice...
  6. Metanoia

    Videos on past year MCQ A level chemistry http://metatutor.weebly.com/

    Videos on past year MCQ A level chemistry http://metatutor.weebly.com/
  7. Metanoia

    Chemistry: Post your doubts here!

    I made a typo in the previous message, the unknown x is for partial pressure (not moles) of CO. solve for x...
  8. Metanoia

    Chemistry: Post your doubts here!

    Try using the method shown in the previous question and express the Kp in terms of the equilibrium concentrations. Let the unknown pressure of CO be x. Post what you have after that and I'll guide you from there if you're still stuck. Edited: Changed "moles of CO" to "pressure of CO"
  9. Metanoia

    Chemistry: Post your doubts here!

    There are errors in your drawings (which is why it is important for me to see them rather then provide the answer straightaway). This will explain why B is the answer.
  10. Metanoia

    Chemistry: Post your doubts here!

    Yes, you can simplify it in that way. Answer is B.
  11. Metanoia

    Chemistry: Post your doubts here!

    You are actually, right. The 3rd electron is in the inner shell. So if forms X2+. Sometimes the values in the table are "inspired" from the data booklet. So it referring to the data booklet can also confirm the answer. we can see that it "resembles" the element of Calcium
  12. Metanoia

    Chemistry: Post your doubts here!

    Try drawing out the resulting products from A and B. You should be able to see that B gives us the desired product. Yes. But F-F has three lone pairs on each F atom , H-F has no lone pairs on the H atom. Thus, the overlapping orbitals effect is much more significant than the repulsion...
  13. Metanoia

    Chemistry: Post your doubts here!

    Form an equation between the Kc and the respective concentrations,then solve for the concentration of HI
  14. Metanoia

    Chemistry: Post your doubts here!

    C is obtained by reacting methylbenzene and bromine in UV light (free radical substitution). Halogen carrier will attach bromine to the ring, and not the side chain.
  15. Metanoia

    Chemistry: Post your doubts here!

    heat released by the reaction = mass of water x specific heat capacity of water x temperature rise = 50 x 4.2 x 2.5 = 525 kJ We have 0.00875 moles of NaOH and 0.00875 moles of HCl, so we can take either reactant as limiting reactant. heat of reaction = heat/moles of limiting reactant = - 525...
  16. Metanoia

    Chemistry: Post your doubts here!

    You are on the right track by first counting the number of carbons. Actually, both C AND D start with seven carbons, so we eliminate both C and D. Therefore, we focus on A and B. Step 1: Replace the Br atom with CN Step 2: hydrolyze the CN to COOH Generally, the smaller the atoms orbitals that...
  17. Metanoia

    Chemistry: Post your doubts here!

    Rather than me giving away the answer straight away, perhaps you can draw out what you think are the intermediate products, then I'll try to correct you from there.
  18. Metanoia

    Chemistry: Post your doubts here!

    Hydrogen bromide: (Organic halogen compound formed) HBr (g) will react and the Br will substitute the OH group. Alkaline iodine: (No organic halogen compound formed). This is the iodoform test to test for the presence (appearance of yellow ppt) of certain structures of alcohol and carbonyls...
  19. Metanoia

    Chemistry: Post your doubts here!

    Statement 1: (TRUE) Less P means less concentration of reactants, so slower rate of production of S and R. Statement 2: (TRUE) A different catalyst in expt 2 might lower the activation energy to a lesser extent than expt 1, so the rate of achieving eqm and production of S and R is slower...
  20. Metanoia

    Away until end of the year. Will not be able to reply to messages. Visit my website for help on...

    Away until end of the year. Will not be able to reply to messages. Visit my website for help on past MCQ papers. Good luck for the exams!
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