Which of the following shows a valid combustion reaction? 2al + 2o2 → 2alo + o2 c2h4 + 3o2 → 2co2 + 2h2o 2ch4 + o2 → 2co + 4h2 ca + o2 → caoh

The valid combustion reaction is

. This is because it has been experimentally proven that hydrocarbon combustion produces carbon dioxide and water.

The first reaction is incorrect because we have oxygen as a product when in actual fact, the reaction should just produce a metal oxide and a lot of heat.

The third reaction is incorrect because methane is a hydrocarbon and we expect the reaction to produce carbon dioxide and water.

The last reaction is incorrect because we expect to produce a metal oxide as opposed to a metal hydroxide when a metal reacts with oxygen.

h let me think

a electronegativity decreases beacuse the size of nucleus is bigger.