Explain why CO₂ and CCl₄ are both nonpolar even though they contain polar bonds.

Video transcript

Hi everyone here, we have a question telling us that even though carbon di sulfur and silicon tetra fluoride contain polar bonds, they are both non polar molecules. And our goal here is to explain. So first we're gonna draw our Lewis structure. So we're going to add up our balance electrons and the balance electrons is based on the role on the periodic table. So we have carbon which has four, we have sulfur and we have two of them. So that's six times two For a total of 16. So carbon is going to be our central atom and we're going to be bonded to two cell furs and we want to fill the octet. So we're going to double bond. So we've used 2468 valence electrons. And then we're going to use 10, 12, 14, 16. Now let's draw silicon tetra fluoride. So Silicon based on its calm on the periodic table has four valence electrons for ng we have four of them. So that's going to be seven times four, Which equals 28 For a total of 32 valence electrons. So it's going to have silicon in the middle surrounded by four floor rings. And we want to fill our octet. So we've already used 2468 of our valence electrons. So now we're gonna use 12 14 16 18 2022, 24, 26, 28, 30 and 32. Now let's draw our di pole arrows. So we have di pole moments going this way and this way for carbon di sulfide and we have them going this way this way this way and this way for silicon tetrachloride. Now, if we look, we see that there is a line of symmetry in both of these, and that line of symmetry is going to cause these dipole moments to cancel out. So our di pole moments are going to cancel out due to symmetry, and that's going to make them both non polar. And that is our final answer. Thank you for watching. Bye.