How many grams of o2 are needed in a reaction that produces 75.0g na2o?

The equation that describes the reaction between Na and O2 is as follows:
4Na + O2 > 2Na2O

Using the periodic table:
molar mass of Na = 23 grams
molar mass of O2 = 2*16 = 32 grams
molar mass of Na2O = 2(23) + 16 = 62 grams

From the balanced reaction:
32 grams of oxygen are required to produce 2*62 = 124 grams of Na2O.
Therefore, to know the amount of O2 that would produce 75 grams of Na2O, we will simply use cross multiplication as follows:
mass of O2 = (32*75) / 124 = 19.35483871 grams

Answerchemical energy;

Sink to the bottom. addition of potassium nitrate past it’s dissolution capacity at a particular temperature will cause the extra to just sink to the bottom of the glass.however, if you were to raise the temperature of the solution prior to dissolving it, and then slowly decrease the temperature after the dissolution, you would create a “supersaturated” solution - a solution that has more solute dissolved into it than should be allowed. if you add any extra solute past this, the entire solution would “crystallize,” and this is how you get those cool videos on youtube.