A major component of gasoline is octane (C8H18) . When liquid octane is burned in air it reacts with oxygen (O2) gas to produce carbon dioxide gas and water vapor. Calculate the moles of octane needed to produce 2.5 mol of water. Be sure your answer has a unit symbol, if necessary, and round it to 2 significant digits.

Inside a flashbulb, oxygen surrounds a thin coil of magnesium. when the flashbulb is set off, a chemical reaction takes place in which magnesium combines with oxygen to form magnesium oxide. which of the chemical equations matches the reaction above? a. mg + o2 mgo2 + energy b. 2mg + o mg2o + energy c. 2mg + o2 2mgo + energy d. mg + o mgo + energy