Formic acid is responsible for the sting of ant bites. By mass, formic acid is 26.10% C, 4.38% H, and 69.52% O. The molar mass of formic acid is 46.02 g/mol. Determine the molecular formula of formic acid and draw its Lewis structure.

Video transcript

well, everyone's in this video, we're going to be working with floral methane and we're trying to find out the Lewis structure as well as the molecular formula. So first we know the general formula is going to be CH three cl So, working with that, then we can use that information to first find the proforma. Go ahead and do that first. Okay, so we have our carbon atom hydrogen as well as foreign. The given percentages is going to be 23.8%,, 6.0% and 70.2%. So what we first do is divide the percentages by the atomic masses. So for carbon that's going to be 12 For hydrogen, that's going to be 101 and the for chlorine atom that's going to be 35.45. So putting that into my calculator For our carbon, that's going to be 1.98 for the hydrogen, that's going to be 5.94 and same thing for chlorine, 1.98. So from these three values, the smallest value is going to be our 1.98. So we can divide all the values by 1.98. Again, putting this into my calculator, our carbon will have a value of one. Our hygiene will have value of three and our carbon will have a value of one. So these are going to be how many items we have for our molecular formula. In our case we have again, one carbon, we have three hydra jen's and we have one chlorine atom. So this right here is going to be the first part of our answer. Now moving on, they want to go ahead and have a straw. The lewis dot structure. So let me just go ahead and scroll down a little bit here. Alright, so since we have our formula, we can go ahead and use that to first solve how many valence electrons we have. So for the carbon atom that has four vans electrons, it's in group 48 for hydrogen is in group 18. So there's going to be one per adam in the formula we have three hydrogen atoms. So we'll multiply that number by three. And then for chlorine that's going to have seven valence electrons sits in group 78. So one times three is three. Now I these three numbers up to get us some of 14 fans electrons. So of course our hydrogen atom can only have one bond because of the duet role. Now comparing our carbon to pouring the less electro negative one is going to be carbon and that's going to be our central atom. So again we have our carbon connected to three Hira gens and the one chlorine and to fulfill its octet rule will have three pairs of the lone pairs on the chlorine. So then this right here is going to be the lowest structure for our chloral methane and those two are going to be our final answers for this problem. Thank you all so much for watching.