Submitted by samuelma t3_z8r5za in explainlikeimfive
nmxt t1_iycxau5 wrote
Dissolving is molecules of water hitting the solid particle and taking away pieces of it. Molecules of water are constantly moving around. Temperature is the measure of average molecule speed. So hot water has faster molecules. Faster molecules means that they hit the solid harder and more often. Therefore they dissolve it more quickly.
finlandery t1_iyd555z wrote
Random question... Does breaking stuff from solid make stuff slower aka colder? I know nacl+ water makes it colder but is it always like that
nmxt t1_iyd6ju9 wrote
No it’s not always like that. During dissolving the bonds between the pieces of the solid are broken but new bonds between water molecules and ions are formed. Breaking bonds requires energy, and making bonds releases energy. Therefore, if the pieces of solid are more inclined to bonding with water than with other pieces of the same solid, then overall energy is released and the temperature rises (e.g. sugar). Otherwise, energy is consumed and the temperature falls (e.g. table salt).
PofanWasTaken t1_iyde6cv wrote
How great is the temperature rise from sugar?
nmxt t1_iydzxct wrote
Temperature effects of dissolving sugar (and table salt) are very small.
Belzeturtle t1_iye5e3z wrote
Depends on how much sugar in how much water. But not a lot.
dimonium_anonimo t1_iydmlgv wrote
Why do gases tend to have higher solubility in cold water?
nmxt t1_iydyy4f wrote
Gas molecules are light and fast molecules that can easily be bounced away and leave the liquid altogether. At low temperatures molecule speed is lower, so the gas molecules are less prone to do that.
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