17.2 grams #MgO# are produced according to the following equation: #2Mg + O_2 -> 2MgO#. How many grams of oxygen #O_2# must have been consumed?
The amount of
You need the molar masses of
Determine the moles of MgO by dividing the mass of MgO produced by its molar mass.
I am keeping some guard digits to reduce rounding errors. I will round to three significant figures at the end.
Multiply the moles of MgO times the mole ratio between
Multiply the moles of
You can combine all of the steps as shown below.