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Q & A: Diffusion and heat in water

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Most recent answer: 02/05/2013
Q:
1.Why warm water have a faster molecule than cold water? 2.Why diffusion occurs faster in warm water than cold water?
- ma.cecilia cerbito (age 19)
catarman northern samar
A:

1. This is reallly just a definition. "Warmer" means having more energy for each little part moving around randomly. So things rattle about faster when they're warmer.

2. Since the molecules move faster when they're warm, that helps speed up diffusion. In water there's another effect that's even bigger. The stickiness ("viscosity") of water goes down as it warms up. That's because that extra energy helps the molecules shake loose from each other. WIth lower viscosity, the molecules go farther before they change directions. That's the biggest factor in making the diffusion faster in water.

-Prathum + Mike W.


(published on 02/05/2013)

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