Question
Why should a magnesium ribbon be cleaned before burning in air?
✓
Answer
Magnesium ribbon is more reactive and when it is exposed to air, a layer of MgO is formed on its surface.
$2 Mg(s)+O_2(g) \rightarrow 2 MgO(s)$
This layer of MgO is removed by rubbing with sand paper before burning in air. Therefore, magnesium ribbon easily reacts with oxygen. Thus, magnesium ribbon is cleaned before burning in air.
$2 Mg(s)+O_2(g) \rightarrow 2 MgO(s)$
This layer of MgO is removed by rubbing with sand paper before burning in air. Therefore, magnesium ribbon easily reacts with oxygen. Thus, magnesium ribbon is cleaned before burning in air.
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