Likewise, this K molecule bonded with the molecule that got kicked off this so four. So this so four molecule at the same time kicked off this oh or replaced this oh and bonded with H. And we got K two So four. So this is an example of a metaphosis or a double displacement reaction. Now, the last type of reaction we're going to look at is called a combustion reaction. And in this reaction, hydrocarbons are burned in the presence of diatomic gas or diatomic oxygen gas to form carbon dioxide and water molecules. Now, a common example is burning of methane ch four, where our X is one and Y is four in the presence of oxygen.