Explain how you determine the freezing point of a solution that does not have a well-defined transition in the cooling curve.
1 answer:
This question is asking for a method for the determination of the freezing point in a solution that does not have a noticeable transition in the cooling curve, which is basically based on a linear fit method.
The first step, would be to understand that when the transition is well-defined as the one on the attached file, we can just identify the temperature by just reading the value on the graph, at the time the slope has a pronounced change. For instance, on the attached, the transition occurs after about 43 seconds and the freezing point will be about 4 °C.
However, when we cannot identify a pronounced change in the slope, it will be necessary to use a linear fit method (such as minimum squares) to figure out the equation for each segmented line having a significantly different slope and then equal them so that we can numerically solve for the intercept.
As an example, imagine two of the segmented lines have the following equations after applying the linear fit method:
First of all, we equal them to find the x-value, in this case the time at which the freezing point takes place:
Next, we plug it in in any of the trendlines to obtain the freezing point as the y-value:
This means the freezing point takes place after 7.72 second of cooling and is about 1.84 °C. Now you can replicate it for any not well-defined cooling curve.
Learn more:
You might be interested in
1. The measurement turned out to be so expensive since the student did not rely on the significant figures to calculate the edge of the cube and approximate it to the next value (2.1 cm possibly) that would allow a simpler construction and therefore its cost was much lower .
2. The student had to take all the significant figures in his calculations, with which he would have:
Volume = 9.2272203 mL
Since the figure to be constructed is a cube, he had to calculate the cube root of the volume to find the value of the edge of the cube:
Edge of the cube = (Taking into account that
is proportional to mL)
Edge of the cube = 2.097443624 cm
Because the cube edge value is so specific, in order to manage his budget, he was able to order a 2.1 cm cube, which would bring the mass up to 80.29287 g, and in the lab reduce one of the faces to the appropriate weight. .
On the other hand, the main thing he had to do was ask how much it would cost to make a cube with those specifications, especially when they mentioned that it would be "expensive" and he only had $50.
The significant figures guarantee the correct operation of a machinery, a gear, a team in general, for which the accuracy will not only be taken to the millimeter, but sometimes microns or much more specific, as in the case of computer components, Therefore, it is very important, if not, and if arbitrary measurements are taken that do not consider significant figures, the components could not function properly, which would cause a loss in time, effort and manpower.
If you want to learn more about exercises with significant figures, you can see the next link: brainly.com/question/11904364?referrer=searchResults