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When solid potassium is added to water, the temperature of the liqiud goes down .

Is the process Endothermic or Exothermic.

Please explain.

2007-02-12 00:28:04 · 7 answers · asked by Chocolate Strawberries. 4 in Science & Mathematics Chemistry

7 answers

If the reaction were exothermic it would supply energy in the form of heat; and the temperature would rise. Since the temperature dropped, the reaction must have consumed enrgy present in the water... therefore this reaction is endothermic.

2007-02-12 00:32:07 · answer #1 · answered by Larry L 3 · 0 0

This question can often be confusing. Endothermic processes feel cold because they are absorbing energy from their surrounds in order to react (ice warming in your hand). However, the temperature of the system (ice) is increasing if it is endothermic, it is the surroundings (your hand) that feels cold. In this case, the temperature of the liquid decreases because it is releasing energy to the surroundings.

This reaction is violently exothermic.
An excellent demonstration: http://video.google.fr/videoplay?docid=-2134266654801392897

2007-02-12 08:42:20 · answer #2 · answered by Josh 1 · 0 0

Potassium has the tendency to react violently with water (or air) as a matter of fact....its place is topmost in the reactivity series (followed by Na)......which is why it is kept stored in kerosene..... The reaction is very rapid violent and Exothermic as there has got to be release of energy.....the process cannot be endothermic....

2007-02-12 08:44:17 · answer #3 · answered by rad_g16 2 · 0 0

Endothermic.
Endothermic reaction - absorbtion of heat from the surroundings.

Energy is required to break the bonds between the particles when dissolved in water... Therefore, heat is absorbed. If heat is absorbed, then temperature of the surroundings goes down.

2007-02-12 08:35:27 · answer #4 · answered by Adrianne G. 2 · 0 0

If the temperature goes down it is endothermic.

When I have done potassium in water it got warmer.

2007-02-12 08:34:10 · answer #5 · answered by science teacher 7 · 0 0

exothermic reaction as heat is lost not gained causing decrease in temperature

2007-02-12 10:19:35 · answer #6 · answered by JAKE 3 · 0 0

confusing one....but i think its exothermic bcoz
heat given out...so temp. falls (mayb)

2007-02-12 09:14:06 · answer #7 · answered by Krits 2 · 0 0

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