If I had to pick 1 video that summarizes how to solve scientific problems in general (physics, chem, thermo, etc) it would be this video. This is how you solve these type of problems. Understand conceptually what's happening and then be methodical in solving for your unknown(s) using the tools (equations) that apply to the type of system you're dealing with.
The only thing I would add is to do the algebra symbolically first, and "plug and chug" as a final step. Moving those numbers around constantly through each step is a surefire way to lose points and gain frustration. The bad part about frustration is, a small error may convince a student that they are missing something significant when, in fact, they fully understand the problem conceptually, but have dropped a decimal or something.
i spent three discouraging hours last night trying to solve a similar question. I went through 10 videos and tried my Tf problem 4 times. This is the first video that was simple and straight forward. I finally got the correct answer and have a better understanding of what goes on with heat of fusion. THANK YOU!
Hey Toaster! Thanks for the nice feedback and I'm so glad you found it helpful! Let me know if there are other videos/topics that you'd like to see! I'm always looking to make more videos and help more people out!
The graph is the key! Was looking at the equations plugged in and was just not getting it even with the mental visualization of what was happening. Thank you!
Wow. The way you explain things make chemistry so much easier. This really helped me out and I really appreciate your time to make this video. I also like that you don't just do procedures. You actually let us think and understand the problem better. I thank you again Tony!
So in this problem, you assume that all the ice melts and go on to solve it. But what process would you use when only some of the ice melts? And how do you make that determination? for ex: 50g of ice at a temperature of -40C is added to 100g of water at 20C in an insulated container. What is the final temperature after equilibrium is reached? (problem from class notes)
Nice way to make this accessible for weaker students, but a couple of points and errors to note. 1. "mL" which should be "ml" is not an SI unit. Centimetres cubed should be used. 2. 75 g of ice will not melt to give 75 "mL" [sic] of liquid water as their densities are different - doesn't affect the calculation, but a misconception in students 3. best practice it to do the algebra first, then substitute numbers at the end - fewer errors this way.
This is a great explanation. Unfortunately, our local schools are trying to tell my son that the "final" temperature is room temperature. Only difference is that they use a 2 cup example where 1 cup gets 1 cube, other cup gets 2 cubes and they say Tf is the same for both cups. True statement if you wait long enough, but it seems like a super dumbed down way of teaching.
You don't have to multiply by negative if you swap around the Tf and 95 when calculating the cooling of hot water. Remembering that when the hot water cools, the initial temperature would be higher than the final temperature.
Thank you so much. I didn't understand how to set up those equations. Like why are they in the order they are? But after watching this video, it makes perfect sense. edit: the question came on the final and I got it right!
i know this video is 8 years old but I am really confused about a homework question I have, where part of the water freezes after adding the ice and I'm struggling to visualise it on a picture. any help?
I would solve for how much energy it takes to heat up the ice, and melt it completely, then compare that to how much energy the water has available to give as it cools down to 0C. That should give me a good idea of where the 'end point' is going to be, then set up a new equation with that in mind. I can make a new video if you provide a specific problem!
HELP!! i have a burning question i've been pondering on for so long. what if we don't know what the final state is? for example if the ice is below freezing temperature and the amount is much more than that of water, how do we know which phase of substance absorbs/releases the latent heat?
I think it depends on the mass of the ice and water. Remember that things that weigh less are easier to heat/cool. For example, say that your ice has much more mass than the water, then your thermal equilibrium i.e. the final temperature of the system will be in the negatives. Similarly, if the mass of the water was much higher, then the ice will definitely melt.
Hii! I came here because I'm studying the same concept in physics. However, the second step with the heat of fusion is not familiar to me at all. Can someone please explain?
10 gram of ice at minus 10 degree Celsius is dropped into 10 gram of water at 60 degree Celsius find the final temperature of the mixture how much ice will melt
