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Exothermic reactions release heat, causing its temperature to fall. If the reaction is lessening the temperature of the object while releasing all the heat, then you know that the reaction is indeed exothermic. Hope this helps!
The Lewis structure the student drew is incorrect. The total number of electrons in bonds and lone pairs is equal to the total number of valence electrons available, then a valid Lewis structure is produced.
The correct structure is the following:
The structure that was drawn by the student was incorrect because the total number of electrons around Oxygen were incorrect, there were 6 instead of 8, which was against the octet rule. The correct structure should have 8 electrons around each atom.
This process is called meiosis! good luck!
In the given reaction potassium metal is placed in water and when a reactive metal is placed in water, it reacts with water to form metal hydroxide and hydrogen gas, as a result, potassium hydroxide and hydrogen gas are produced in the reaction. A redox reaction is a reaction in which a substance is oxidized during the reaction whereas some other substance is reduced during the reaction, simultaneously.
The given chemical reaction is:
2K(s) + 2H20(l) arrow 2KOH(aq) + H2(g)
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