Question

In the combustion of hydrogen gas, hydrogen reacts with oxygen from the air to form water vapor. hydrogen+oxygen⟶water If you burn 58.9 g of hydrogen and produce 526 g of water, how much oxygen reacted?

Answer 1

Answer:

$m_{O_2}=467gO_2$

Explanation:

Hello.

In this case, for the reaction:

$2H_2+O_2\rightarrow 2H_2O$

The correct way to compute the oxygen that reacted is by considering the mass of hydrogen, 58.9 g, its molar mass, 2.02 g/mol, the 2:1 mole ratio between hydrogen and oxygen and the atomic mass of that gaseous oxygen 32.00 g/mol; therefore we use the following stoichiometric procedure:

$m_{O_2}=58.9gH_2*\frac{1molH_2}{2.02gH_2}*\frac{1molO_2}{2molH_2} *\frac{32.00gO_2}{1molO_2} \\\\m_{O_2}=467gO_2$

The same result could have been obtained by using the mass of water since the law of conservation of mass is obeyed here.

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