Rapid Water temperature decrese???

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athanzxyt
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Rapid Water temperature decrese???

Post by athanzxyt » December 17th, 2018, 12:28 pm

A few days ago, I was at an invitational. The ES took the water out of the container (at 70.4 degrees Celsius) and poured it into our beaker and box. We shut the lid tightly 10 seconds after the ES finished pouring. We based our prediction score on the 70.4 degrees the gave us. Apparently, the first reading the temperature probe got was 61.5 degrees. Nearly 10 degrees lower. Can someone explain to me what happened? One of my teammates said that "the water just cools rapidly during that time period"

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Re: Rapid Water temperature decrese???

Post by UTF-8 U+6211 U+662F » December 17th, 2018, 12:47 pm

athanzxyt wrote:A few days ago, I was at an invitational. The ES took the water out of the container (at 70.4 degrees Celsius) and poured it into our beaker and box. We shut the lid tightly 10 seconds after the ES finished pouring. We based our prediction score on the 70.4 degrees the gave us. Apparently, the first reading the temperature probe got was 61.5 degrees. Nearly 10 degrees lower. Can someone explain to me what happened? One of my teammates said that "the water just cools rapidly during that time period"
Your teammate is correct. Whenever you pour water, it cools rapidly. This is pretty much unavoidable. I would recommend taking the temperature of the water after you pour it for your tests and at the competition.

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Re: Rapid Water temperature decrese???

Post by JoeyC » December 17th, 2018, 4:12 pm

On this note, remember to conduct tests on the water on a range between 50-70*C, not just 60-70*C; often times once poured, the water temperature will be less than 60*C, so you must be prepared.
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Re: Rapid Water temperature decrese???

Post by John Richardsim » December 17th, 2018, 6:16 pm

Keep in mind that the beaker starts at room temperature (20 to 25 degrees Celsius). When the water is poured in, there is an immediate decrease in temperature as the beaker and water reach an equilibrium temperature.

If I recall correctly my partner and I made this same mistake at our invitational. We worked around this by going off of the initial, pre-pour temperature when collecting data.
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Re: Rapid Water temperature decrese???

Post by CPScienceDude » December 17th, 2018, 7:59 pm

Same here. This is how i collected all of my data too. Though I realized this while making my prediction and decreased my prediction and ended up only being 1 degree off.
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Re: Rapid Water temperature decrese???

Post by satvik03 » January 9th, 2019, 4:15 pm

If you think about the room temperature, which can be up to and around 50 degrees lower than 70 degrees, a lot of heat must be lost when the ES is pouring the water. The more time spent pouring, the more temperature lost. So I guess all you can do is hope that the ES pours quickly. Your predictions should be made after pouring water. We found this out the hard way lol. :D
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