Water gas, also known as synthesis gas or "syngas", is a mixture of carbon monoxide (CO) and hydrogen (H₂). When water gas reacts with a catalyst, typically consisting of a combination of cobalt and molybdenum, it can undergo a reaction to form methanol (CH₃OH).

This is known as the methanol synthesis reaction and can be written as:

$$\mathrm{CO(g)} + 2\mathrm{H}_{2}(g) \rightarrow \mathrm{CH}_{3}\mathrm{OH(g)}$$

This reaction is widely used in industry for the production of methanol, which can be used as a solvent, an antifreeze, a fuel, and as a feedstock for the production of chemicals.