4.3 Draw the structures and name the shapes of the following molecules: (a) HCN; (b) CH2F2.

[405169322]

4.3 Draw the structures and name the shapes of the following
molecules: (a) HCN; (b) CH2F2.

[Rhea Churi 4K]

The name of the VSEPR structures are as follows
a) linear
b) tetrahedral

[Esha Harwalkar 3F]

Adding on to this, for part A, the VSEPR formula for a.) would be AX2 (with 2 bonds to the central atom) and for b.) would be AX4 (with 4 bonds to the central atom)

[Camille 4I]

How do you know that the two bonds with hydrogen are next to each other, versus across the molecule from each other?

[Shutong Hou_1F]

How do you know that the two bonds with hydrogen are next to each other, versus across the molecule from each other?

I think that it does't matter, and there are 2 reasons.
1) they are all single bonds, so arranging the hydrogen atoms next to each other or across from each other doesn't make different resonance structures to form;
2) the Lewis structure is 2-D, whereas in reality, or according to the VSEPR model, the shape is tetrahedral, meaning that the bond angles are all equal to 109.5 degrees, totally equivalent to each other;