Methyl bromide (CH3Br or bromoethane) is an alkyl halide compound. It has only one carbon atom. Lewis structure of CH3Br contains 3 C-H bonds and 1 C-Br bond. Carbon atom is the center atom and bromine atom has 3 lone pairs. We will learn how to draw lewis structure of CH3Br step by step in this tutorial.
Figure of CH3Br lewis structure is given above and you can see how atoms are joint with other atoms. Also, there are no charges on atoms and CH3Br also does not have an overall charge.
An organobromine compound which exist as a nonflammable gas at room temperature. It is an ozone-depleting compound with one bromine atom. Methyl bromide is an acute toxic chemical and should carefully handle with proper safety equipments.
There are several steps to draw the lewis structure of CH3Br. Each step is explained in detail in this tutorial.
There are 3 elements in CH3Br molecule; hydrogen, carbon and bromine. Hydrogen is a group IA element and has only 1 electron in its valence shell. Bromine is a group VIIA element in the periodic table and contains 7 electrons in its last shell. Carbon atom has 4 electrons in its last shell because it is a IV group element. Now we know how many electrons are includes in valence shells of atoms.
Total valance electrons pairs = σ bonds + π bonds + lone pairs at valence shells
Total electron pairs are determined by dividing the number total valence electrons by two. For, CH3Br, total pairs of electrons are 7 (14/2) in their valence shells.
To be the center atom, ability of having greater valance and being most electropositive element in the molecule are important facts. These are not essential. But those two facts play a major role in selecting center atom of a molecule.
However, CH3Br is a simple molecule. Carbon atom has the more chance to be the center atom than hydrogen and bromine atoms.
After deciding the center atom and sketch of CH3Br molecule, we mark lone pairs on atoms. Remember that, there are total of 7 electron pairs to mark on atoms as bonds and lone pairs.
There are no charges on atoms and we do not need to the step of reducing charges of atoms.
Questions
There are three single bonds between carbon atom and three hydrogen atoms. As well, there is a one carbon-bromine atom. Finally, there are four sigma bonds around the center atom, carbon. Therefore, molecular geometry and shape of CH3Br molecule is tetrahedral.
Each hydrogen atom give one electrons to make single bonds with carbon atom. Carbon gives its all four electrons to make bonds with hydrogen and bromine atom. But, bromine only gives one electron to make a bond with carbon atom.
Only bromine atom has lone pairs. Bromine has three lone pairs in bromoethane.