In the reaction 2k + 2h2o → 2koh + h2, which compound has an element ratio of 2 : 1? h2o h2 k koh

The compound that has the element ratio 2:1 is 2H20.

In 2H2O, four atoms of hydrogen react with two hydrogen of oxygen to form molecules of water. Four divided by two will give two, that implies ratio 2; 1. This implies that, two atoms of hydrogen will react with one atom of oxygen to give a molecule of water.