Which of the following is an example of a double-replacement reaction? a. 3k + alcl3à 3kcl + al b. koh + hbr à kbr + h2o c. ch4 + 2o2à co2 + 2h2o d. cu + 2h2so4à cuso4 + so2 + 2h2o

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