Drawing the Lewis Structure for SnCl2

Viewing Notes:

  • The Lewis structure for SnCl2 requires you to place less than 8 valence electrons on Tin (Sn).
  • You might want to put a double bond on the Chlorine (Cl) atom but Cl does't normally form double bonds due to its high electronegativity. If you check the formal charges you'll see that a double bond in the SnCl2 Lewis structure has several non-zero charges.
  • You'll want to calculate the formal charges on each atom to make sure you have the best Lewis structure for SnCl2. SnCl2 is a good example to help understand how to calculate formal charges.

Transcript: Hi, this is Dr. B. Let's do the SnCl2 Lewis structure. On the periodic table, tin, group 4; and Chlorine, group 7, sometimes called 17, has 7 valence electrons, but we have two of them, so we'll multiply that by two. Four plus 14: 18 total valence electrons. Tin is the least electronegative, goes at the center. Let's put the Chlorines out here on the side.

So we have 18 valence electrons. We'll put two between atoms to form chemical bonds, then around the outside. So we have 2, 4, 6, 8, 10, 12, 14, 16, and then on the central atom 18; and we've used all our valence electrons. Chlorines both have eight valence electrons. Tin only has six, but that's OK because tin is lower than period 2, row 2 on the periodic table. It doesn't have to have eight valence electrons.

If you check your formal charges, you'll see that they're all zero, so this is the best Lewis structure for SnCl2. This is Dr. B., and thanks for watching.