Atomic Size and Electronegativity

Q. Which of the following is the most stable alkene ?

1. $RCH=C{H}_2$
2. $C{H}_2=C{H}_2$
3. $RCH=CHR$
4. $R_{2}C=C{R}_2$

Q.

In which of these pairs of atoms would the bond be the least polar (i.e., lowest percent ionic character)?

1. H₂S

2. HCl

3. BF₃

4. H₂O

Q. The electronegativity values of the elements are useful in predicting:

1. Nature of an oxide
2. Bond energy of a molecule
3. All
4. Polarity of a molecule

Q. The correct order of atomic radii among the following elements is:

Q. Calculate the electronegativity of fluorine from the following data:
Bond energy of H-H bond $E_{H-H}=104.2kcalmo{l}^{-1}$
Bond energy of F-F bond$E_{F-F}=36.6kcalmo{l}^{-1}$
Bond energy of H-F bond $E_{H-F}=134.6kcalmo{l}^{-l}$
Electronegativity of Hydrogen $X_H=\mathrm{2.1.}$

1. 3.87
2. 2.76
3. -3.87
4. -2.76

Q. Calculate the electronegativity of chlorine from the given data: bond energy of $Cl-F$ bond $\left(61kcalmo{l}^{-1}\right)$, $F-F$$\left(38kcalmo{l}^{-1}\right)$ and $Cl-Cl$ bond $\left(58kcalmo{l}^{-1}\right)$ and electronegativity of fluorine is $4.0$.

1. $2.33$
2. $3.22$
3. $3.33$
4. $2.67$

Q. Size of the following isoelectronic species increase in the order:

1. $M{g}^{2+}<N{a}^{+}<F^{-}$
2. $F^{-}<N{a}^{+}<M{g}^{2+}$
3. $F^{-}<M{g}^{2+}<N{a}^{+}$
4. $M{g}^{2+}<F^{-}<N{a}^{+}$

Q. The correct statement for the following scheme of reactions is:
$4NCl3+3LiAlH4\to A+3LiCl+3AlC{l}_3$
$4PC{l}_3+3LiAlH4\to B+3LiCl+3AlC{l}_3$
$4AsC{l}_3+3LiAl{H}_4\to C+3LiCl+3AlC{l}_3$
$4SbC{l}_3+3LiAl{H}_4\to D+3LiCl+3AlC{l}_3$

1. D is more basic than C
2. D is more basic than B
3. B is less basic than A
4. A is more basic than B, C and D.

Q. <!--td {border: 1px solid #ccc;}br {mso-data-placement:same-cell;}--> The correct order of the atomic radii of $C,Cs,Al$ and $S$ is:

JEE MAIN - 2019

Q. Which of the following have no unit?

1. Electronegativity
2. Electron Gain Enthalpy
3. Ionisation Energy
4. Metallic Character