Consider the reaction: H₂( g) + Br₂( g) → 2 HBr( g) The graph shows the concentration of Br₂ as a function of time.

b. Make a rough sketch of a curve representing the concentration of HBr as a function of time. Assume that the initial concentration of HBr is zero

Video transcript

Welcome back everyone in this example, we're given the following reaction and we're told that the plot below shows the concentration of oxygen as the reaction progresses. And we can see that our concentration of oxygen is going to be decreasing as time progresses. And that is due to the fact that oxygen is a reactant according to our reaction. And so we can say that our concentration Access for 0.2 is decreasing based on our given graph. So we're going to assume that the initial concentration of water is zero. And we need to draw a plot showing the concentration of water as the reaction progresses. So our first step is to write out a rate for our reaction And we can say that our rate of our reaction is going to equal for our reactant, H. two. We have a negative rate Since it's a reactant and we will be losing it so that is negative one times the change in concentration of H2, divided by the change in time. This is equal to the second reactant which we have as oxygen, so equal to the change in concentration of oxygen where oxygen has a coefficient of one half. So we would have negative one Divided by 1/2. And then this is divided by the change in time. And then this is set equal to for our product side, we have the change in concentration of water Which will have a positive coefficient of one and it's a product. So it's positive. So this is divided by delta T. For change in time. And so to simplify this, we can say that our rate of our reaction is equal to negative one times delta concentration of H. Two divided by delta T. Equal to negative two times delta concentration of 02 divided by delta T. And then equal to delta concentration of water divided by delta T. And based on the rate that we wrote, we can say that the rate of change of our concentration of water is going to be half that of the concentration of oxygen Based on our coefficient of two here and so what that means is that our plot for the concentration versus time for water is going to pretty much be the same as our or the same shape as our original plot. However, we're going to start out at the origin for our plot. So all paste down below what that graph should look like. So we should have the below graph that we draw out for our plot of concentration of water versus time. And as you can see our plot for the concentration of water begins at the origin of our graph. And instead of having a axis for concentration of water decreasing as we saw above. For oxygen, we have an access of our concentration of water that is increasing as time goes on. And that is due to the fact that water is our product in our reaction as we wrote above. So water is a product. And so its concentration definitely should be increasing as the reaction progresses, and it's specifically increasing by half the rate of oxygen as we stated above. And so for our final answer, we would box in the below graph that we have drawn here to represent our concentration of water as the reaction is progressing. So I hope that everything I read was clear. If you have any questions, please leave them down below, and I will see everyone in the next practice video.