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

Answer : option c) heat is released during the process.explanation :

the enthalpy of formation of water is given as -285.8kj/mol, which states that the enthalpy of formation is negative.

negative enthalpy of formation indicates that the heat is released during the reaction process. the heat is released from reaction to the surroundings the enthalpy is expressed with a negative sign with the energy given out in the reaction process.

the formation of water takes place by giving out heat which is -285.8 kj/mol.