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Day 489: JEE Mains Chemistry

5 questions. Try each one first, then open its answer.

  1. Question 1

    Organic Reaction Mechanisms. Asked once: 25 Jan 2023

    49
    The correct sequence of reagents for the preparation of QQ and RR is

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  2. Question 2

    Solutions. Asked once: 29 Jan 2023

    54
    Solid Lead nitrate is dissolved in 1 litre of water. The solution was found to boil at 100.15∘C100.15^{\circ}C. When 0.2 mol0.2\text{ }mol of NaClNaCl is added to the resulting solution, it was observed that the solution froze at −0.8∘C-0.8^{\circ}C. The solubility product of PbCl2PbCl_{2} _____formed is ×10−6\times10^{- 6} at 298 K298\text{ }K. (Nearest integer) (Given: Kb=0.5 Kkgmol−1K_{b}= 0.5\text{ }Kkgmol^{- 1} and Kf=1.8 K kg mol−1K_{f}= 1.8\text{ }K\text{ }kg{\text{ }mol}^{- 1}. Assume molality to be equal to molarity in all cases.)

  3. Question 3

    Some Basic Concepts of Chemistry. Asked once: 2021 Paper 13

    26
    Methylation of 10 g10\text{ }g of benzene gives 9.2 g9.2\text{ }g of toluene, the % yield is:

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  4. Question 4

    Structure of Atom. Asked once: 30 Jan 2023

    133
    The wave function (Ψ)(\Psi) of 2 s2\text{ }s is given by
    Ψ2 s=122π(1a0)1/2(2−ra0)e−r/2a0\Psi_{2\text{ }s}=\frac{1}{2\sqrt{2\pi}}\left( \frac{1}{a_{0}} \right)^{1/2}\left( 2 -\frac{r}{a_{0}} \right)e^{- r/2a_{0}}
    At r=r0r =r_{0}, radial node is formed. Thus, r0r_{0} in terms of a0a_{0}

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  5. Question 5

    The d- and f-Block Elements. Asked once: 14 Jun 2022

    126
    Metals generally melt at very high temperature. Amongst the following, the metal with the highest melting point will be

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