Question

Please btao koi toh
Electronaffinity of CL>F (explain)
And
Out of NF3 and NH3 which will have more dipole moment

Answer 1

We already know that electronegativity of fluorine is more than chlorine. But elctron affinity of Cl is more, because of the extremely small size of fluorine. Being this small, when fluorine atom acquire an electron to become fluorine anion, the electrons already present in it push it away, that is repel it with greater force, obviously because of its size, you know the atom cannot accommodate another electron, thus the fluorine anion becoming very reactive. On the other hand, chlorine being bigger than flourine, can easily accommodate one other electron, and form a chloride anion. That's why, electron affinity of Cl is more than F.

Now looking at NH3 and NF3, you should know, that F is more electronegative than H. In the NH3 structure, thus the orbital dipole, which is due to its lone pair (present in N) the direction of dipole is same as the resultant dipole, adding to the electronegativity of N, creating more dipole moment. But in NF3 the orbital dipole is in the opposite directions. Thus they cancel out each other's dipole, resulting in a dipole moment which is almost equal to zero. So clearly, NH3 has more dipole moment.

Hope this helps!