How many grams of Oxygen are needed to burn 12g of Magn... – Chemistry

Chemistryhard · Past Paper

How many grams of Oxygen are needed to burn 12g of Magnesium completely? (Mg=24, O=16)

A8g

B16g

C32g

D4g

✓ Correct Answer: A — 8g

2Mg + O2 -> 2MgO. 48g Mg reacts with 32g O2. So 12g Mg reacts with (32/48)*12 = 8g O2.

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