Answer:
The image on the right
Explanation:
There are two molecules in this diagram, 0.2 mol Cl and 0.2 mol H. In cases like these, it is helpful to note the equation: [tex]H^++Cl^-[/tex]→ HCl. Since this equation is already balanced, we know that this equation is an accurate ratio for how much HCl there should be based on the number of other reactants. Keep in mind that even though 0.2 mol of both H and Cl are reacting, they add up to 0.2 mol of HCl, not 0.4 mol (similar to how a pen and a pen cap equal a full pen, not 2 full pens). This means we simply need to follow the 1:1 ratio of mols to get to the proper molarity of 2.0 M of HCl.
Since everything is in one liter, we do not need to worry about a molarity calculation, and we can instead count the number of mols in each image until it adds up to 2 mols of any element (we can use our ratio to confirm that 2 mols worth of dots of both reactants in this reaction will result in a 2.0 M HCl solution). Specifically, we can divide 2 mols by how much each dot is worth, in this case 0.2 mol each, in order to find how may dots we are looking for. 2/0.2 = 10, so we are looking for the diagram with 10 of each dot in it, which is the image on the right.
