Many metals react with oxygen gas to form the metal oxide. for example, calcium reacts as follows: 2ca(s) + o2(g) → 2cao(s) calculate the mass of calcium oxide that can be prepared from 7.97 g of ca and 5.31 g of o2.

11.14 grams of CaO

Explanation:

The reaction is:

As per equation one mole of oxygen gas will reaction with two moles of calcium to give two moles of calcium oxide.

the moles of oxygen reacted =

moles of calcium reacted =

the moles of oxygen that will react with 0.199 moles of Ca =

The moles of CaO produced = 0.199

Mass of calcium oxide produced = moles X molar mass

= 0.199 X 56 = 11.14g

X

i believe the answer is three water molecules