Question

In an experiment magnesium ribbon was heated in air. The product was found to be heavier than the original ribbon. Potassium manganate 7 was on the other hand, heated in air and product formed was to be lighter. Explain the difference on the observation made

Answer 1

Burning a magnesium ribbon in the air is an addition reaction while heating potassium manganate 7 is a decomposition reaction.

Addition and decomposition reactions

Magnesium burns in air to produce magnesium oxide as follows:

$2Mg + O_2 --- > 2MgO$

Potassium manganate 7 burns to produce multiple products as follows:

$2 KMnO_4 --- > K_2MnO_4 + MnO_2(s) + O_2$

Thus, the MgO will be heavier than Mg. On the other hand, $MnO_2$ will be less heavy than $KMnO_4$.

More on reactions can be found here: brainly.com/question/17434463

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