Final answer:
When liquid oils are hydrogenated, saturated fat is formed. Trans fats are a type of unhealthy fat formed during the hydrogenation process, which can increase the risk of cardiovascular disease.
Step-by-step explanation:
When liquid oils are hydrogenated, the following type of fat is formed: saturated fat.
In the food industry, oils are artificially hydrogenated to make them semi-solid and increase their shelf life. Hydrogen gas is bubbled through oils to solidify them, and during this process, double bonds in the cis-conformation in the hydrocarbon chain may be converted to double bonds in the trans-conformation, forming trans fats.
Trans fats have been linked to an increased risk of cardiovascular disease and are considered unhealthy when consumed in excess.