headache pills

[kia cat]

Effervescent headache pills, how come they dissolve quicker in warm or hot water than in ice cold, or is it my imagination? Thanks

[steveb]

basically it is because in warm water all the molecules have a greater average energy than in cold water. This increased energy means that the molecules of warm water are moving around at a greater rate and consequently coming into contact with the pill more often. As more water molecules are hitting the pill in the same space of time it dissolves into the water faster. Another example would be trying to make a cup of tea with cold water.