Question

Расположить в порядке возрастания полярности связи:HFNH3H2O CH4

Answer 1

Думаю так.
CH4, 
NH3,
H2O,
HF         

Answer 2

Sorting the Molecules by Increasing Polarity:

To determine the order of increasing polarity for the molecules HFNH3, H2O, and CH4, we need to consider the polarity of the bonds within each molecule.

1. CH4 (Methane): Methane (CH4) is a nonpolar molecule because it consists of four identical carbon-hydrogen (C-H) bonds. Carbon and hydrogen have similar electronegativities, meaning the electrons are shared equally between them. As a result, there is no separation of charge, and the molecule has no overall dipole moment. Therefore, CH4 is the least polar molecule among the three.

2. H2O (Water): Water (H2O) is a polar molecule due to its bent molecular geometry and the electronegativity difference between oxygen and hydrogen. Oxygen is more electronegative than hydrogen, causing the oxygen atom to pull the shared electrons closer to itself. As a result, the oxygen end of the molecule becomes slightly negative (δ-) while the hydrogen ends become slightly positive (δ+). This separation of charge gives water a net dipole moment. Therefore, H2O is more polar than CH4.

3. HFNH3 (Ammonia Borane): Ammonia borane (HFNH3) is also a polar molecule. It contains polar covalent bonds between hydrogen and nitrogen (H-N) and between fluorine and nitrogen (F-N). The electronegativity difference between nitrogen and hydrogen/fluorine causes the nitrogen atom to have a partial negative charge (δ-) and the hydrogen/fluorine atoms to have partial positive charges (δ+). Additionally, the molecular geometry of HFNH3 contributes to its polarity. The molecule has a pyramidal shape, with the nitrogen atom at the apex and the hydrogen/fluorine atoms at the base. This arrangement leads to an overall dipole moment. Therefore, HFNH3 is the most polar molecule among the three.

Order of Increasing Polarity:

Based on the information above, we can arrange the molecules in order of increasing polarity as follows:

CH4 < H2O < HFNH3

Please note that this order is based on the polarity of the molecules and not the individual bonds within them.