\textbf{212.} How many grams of oxygen gas released from the thermal decomposition of 3/0 mol of potassium chlorate can be obtained, assuming both reactions are 100\% efficient? $(N = 14,\ O = 16,\ Na = 23:\ \text{g.mol}^{-1})$
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(1) $36$ \qquad (2) $41$ \qquad (3) $68$ \qquad (4) $76/5$
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