Yes, he was supposed to do that. His answer is 344 J/g, but if he had done it correctly, the answer would have been 328 J/g, which is a little closer to the true value of 334. In any case, when I did this lab in my chemistry class, three trials, my values were 229, 279, and 258. Very disappointing, so what do I know? 🙂
Hi Stephen, I have a dilemma for you. I just did this exact lab in chemistry class and am having difficulties with the calculations. This video of yours has helped a lot and made it seem way less intimidating than the chemistry prof I have! However, during my calculations, the q number I got for my water formula ended up being a negative number, thus making my heat of fusion of ice negative (which is wrong, since that would state that the reaction was exothermic and releasing heat vs the ice absorbing the heat). I am not quite sure where to go from here, as all of my measurements are correct
It sounds like you used a negative temperature for delta T (for example, if it went from 65 to 2 degrees, you'd call it -63 degrees. This negative delta T value would end up giving you a negative heat of fusion. For this lab I treat the change in temperature as an absolute value number. In the case I just mentioned, I'd call the change in temperature 63 degrees (not negative 63 degrees). This would get a positive heat of fusion value.
THANK YOU SO MUCH FOR THIS! I AM STRUGGLING WITH OUR LABORATORY EXPERIMENT AND THIS VIDEO SAVED ME!!!
brogad... you're a legend
thanks i just understood this topic well now
Amazing explanation!!
I have a question , ice melts at zero , then final T has to be zero , what am I missing ?
Thank you 😊
Ice turned into water at 0 C but also absorbed some heat to reach the final temperature. Weren't you supposed to add another 636 J for that portion?
Yes, he was supposed to do that. His answer is 344 J/g, but if he had done it correctly, the answer would have been 328 J/g, which is a little closer to the true value of 334.
In any case, when I did this lab in my chemistry class, three trials, my values were 229, 279, and 258. Very disappointing, so what do I know? 🙂
Hi Stephen, I have a dilemma for you. I just did this exact lab in chemistry class and am having difficulties with the calculations. This video of yours has helped a lot and made it seem way less intimidating than the chemistry prof I have!
However, during my calculations, the q number I got for my water formula ended up being a negative number, thus making my heat of fusion of ice negative (which is wrong, since that would state that the reaction was exothermic and releasing heat vs the ice absorbing the heat). I am not quite sure where to go from here, as all of my measurements are correct
It sounds like you used a negative temperature for delta T (for example, if it went from 65 to 2 degrees, you'd call it -63 degrees. This negative delta T value would end up giving you a negative heat of fusion. For this lab I treat the change in temperature as an absolute value number. In the case I just mentioned, I'd call the change in temperature 63 degrees (not negative 63 degrees). This would get a positive heat of fusion value.
Yes.