Nitrogen 1N22 and hydrogen 1H22 react to form ammonia 1NH32. Consider the mixture of N2 and H2 shown in the accompanying diagram. The blue spheres represent N, and the white ones represent H. (d) If so, how many of which type are left over?

How many N2 molecules are left over?

Video transcript

Welcome back everyone. The reaction between chlorine and oxygen gas produces die chlorine dioxide. The illustration below shows a mixture of chlorine and oxygen. The chlorine atoms are represented by green spheres and then the oxygen atom is represented by red spheres, identify if there are any reactant molecules left, give the identity of the molecule and determine how many molecules are left. Let's begin by writing out our balanced equation between chlorine, gas and oxygen gas, which again produces die chlorine dioxide according to our prompt. So this is a solid. So if we go ahead and place a coefficient of three in front of our oxygen on the reactant side, that changes our total number of oxygen on the reacting side to six moles of oxygen. So we need six moles of oxygen on the product side. We only have three, meaning we'll have to place a coefficient of two in front of our diet chlorine dioxide product, giving us four moles of chlorine and six moles of oxygen where our oxygen is now balanced. But now on the react inside chlorine needs to be balanced. And so we'll place a coefficient of two in front of chlorine on the product side, sorry, on the reactant side. Now giving us four moles of chlorine on both sides and six moles of oxygen on both sides. And so this is now our balanced equation which is going to help us in getting to our answer because our next step is to figure out using psychometric molar ratios how much of our product each reactant produces. And so we'll say die chlorine dioxide produced or we'll just say from for shorthand Chlorine 1st. So beginning with chlorine, we wanna count how many molecules of chlorine we have which are the green molecules. If we count, we see a total of eight. And then for oxygen we would count a total of nine. So eight molecules And nine molecules of oxygen. Beginning with again die chlorine dioxide from chlorine. Our reactant we have as we stated eight molecules of chlorine in which we want to multiply to go from our molar ratio to go from molecules of chlorine in the denominator two molecules of our product die chlorine tri oxide in the numerator. So from our balanced equation we see that that's a 2 to 2 molar ratio and canceling out molecules of chlorine were left with molecules of chlorine dioxide, Die chlorine dioxide. So this should be cl 203. And this will simplify to our di chlorine dioxide made from chlorine being eight molecules of di chlorine dioxide that is produced. Then we have our di chlorine dioxide from our second reactant, oxygen. We counted a total of nine molecules of oxygen. So we're going to multiply by our ratio to go from molecules of oxygen in the denominator two molecules of our product declaring tri oxide in the numerator. And from our balanced equation we see that we have three moles of oxygen for two moles of declaring tri oxide. So that's a 3-2 molar ratio in our numerator. So canceling out our molecules of oxygen were left with molecules of our product declaring trioxide. And this simplifies to a total of six molecules of declaring tri oxide produced from oxygen. So we can see that the reactant that made less product is oxygen. And so we would say that therefore oxygen is our limiting reactant And sorry, this is oxygen. 02 Is our limiting reactant. And so going back to our ratio from our balanced equation between chlorine, our first reactant and oxygen are second reactant. We see that we have a 2-3 molar ratio where we have two molecules of chlorine for every three molecules of oxygen. And so if we know we have nine molecules of oxygen. From our illustration we can say that nine molecules of oxygen need six molecules of chlorine to react based on that ratio. And so for our next step to calculate our molecules of our accessory agent which is chlorine that remain after the reaction, we would take the difference between our molecules of chlorine, which from our illustration is eight molecules of chlorine and we would subtract this from what we know react being six molecules of chlorine. Again, this statement is nine molecules of oxygen needs six molecules of chlorine to react. So this difference will result in our molecules of chlorine that remain equal to two molecules of excess chlorine. And so for our final answers, we've determined that oxygen is our limiting reactant and we have two molecules of our excess reactant, chlorine that remains so our final answer will correspond to choice A and the multiple choice as the correct answer. I hope everything I reviewed was clear, and I'll see everyone in the next video.