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Chemistry: Post your doubts here!
Hmm..I already answered it in the post, it's cobalt. -
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Chemistry: Post your doubts here!
I suppose this is an MCQ question? Use the data booklet and find the sum of 1st I.E and 2nd I.E of Al (577+1820 = 2397) , then see which of the transition metals give the same result. Recall that most metal nitrates decompose under heat to produce metal oxides, so even IF Al(NO3)3 is... -
Chemistry: Post your doubts here!
Covalent forces is the bond of an I atom to another I atom. It is very strong and isn't broken during such heating, i.e. the I2 molecule is not broken into two iodine atoms. Induced dipole-dipole is the weak attraction of an I2 molecule to another I2 molecule. Heating overcomes these forces... -
Chemistry: Post your doubts here!
What are your carbon products for B and D? And their bond angles? What wrong answer did you choose? -
Chemistry: Post your doubts here!
Hi there, could you share your thoughts on the 2 questions so I know why you are stuck. -
Chemistry: Post your doubts here!
Yes. The rotation is between the C-C bonds, doesn't matter C atoms are attached else where. I can't find a video on C=C-C=C, but here is a video of C-C-C-C, where the rotation along the middle bond is shown. -
Chemistry: Post your doubts here!
In this case, the cis-trans is the same as the trans-cis. So your 2nd and 4th are essentially the same molecules. The often neglected part is the the molecule can rotate (twist) along the C-C single bond. -
Chemistry: Post your doubts here!
The book is incorrect. We would not expect the graphs to be totally the same shape, nor have a linear relation. Forces of attraction is depending of size, charges, electrons, 3D packing, etc. there are too many factors to expect totally overlapping graphs for both mp and Bp. More important is... -
Chemistry: Post your doubts here!
Consider all possibilities whenever applicable e.g. cis-cis, cis-trans, trans-cis, trans-trans Post your diagrams and I'll try to tell you where you went wrong. -
Chemistry: Post your doubts here!
Even though the topics covered are similar, the questions for Singapore papers are much tougher and demanding than 9701. It would be best to practice past year papers from Intl' AS and A level instead. -
Chemistry: Post your doubts here!
Both C and D are true statements on their own, but we have to decide which one contributes most to the observation that overall, H2 + I2 --> 2HI is more endothermic than H2 + Cl2 --> 2HCl The reactions requires breaking of I-I and Cl-Cl bonds, and forming of H-I and H-Cl bonds. Comparing I-I... -
Chemistry: Post your doubts here!
High charge density increases covalent character. The cation would be able to attract the electron cloud of the anion, resulting in a slight sharing of the electrons. Recall that sharing of electrons basically means covalent bonding. Start by grouping the elements into types of bonding metallic... -
CHEMISTRY URGENT HELP!
Is your chem paper 9701? If so, you can ignore Singapore's H2 paper. The topics overlap quite a bit, but the Singapore questions are much more demanding. It would be best to clear the past year papers taken in your country first. -
Chemistry: Post your doubts here!
Qn 9. A. Wrong. Cause the ester group is formed on the wrong location. B. Correct. Ester group formed between the alcohol and acid functional groups. C. Wrong. This is supposed to be an acid + carbonate reaction. The COOH should be the one forming COO-Na+ Qn 11. Check for trans isomerism (use... -
Chemistry: Post your doubts here!
Hydrogen will not be able to reduce the carboxylic acid group. To reduce the acid group, we need LiAH4 (lithium aluminum hydride). -
Chemistry: Post your doubts here!
I think you misunderstood the question. They are asking how many moles of H2 and Br2 for separate experiments. H2 in nickel does not reduce COOH groups. Also, if you do get a solution that is none of the 4 options, it's an indication of being wrong, do not simply choose the nearest correct... -
Chemistry: Post your doubts here!
One H2 adds across each C=C bonds, same reasoning for Br2. So 2 moles for both. Which years are these from? -
Chemistry: Post your doubts here!
Hmm...yes. because simply, 1 x heat of neutralization = mass x specific heat capacity x temp rise -
Chemistry: Post your doubts here!
If you are having difficulty figuring out the oxidation states of N and Cl inside NH4ClO4, view them in this manner NH4+ and ClO4- For N in NH4+ : N + 4(+1) = + 1 N = -3 For Cl in ClO4- : Cl + 4(-2) = -1 Cl = +7