What is the molecular formula of methanal?

In the modern industrial method for the production of ethanol, hydration of ethene is carried out in the presence of which substance?

An aldehyde as well as a ketone can be represented by the same molecular formula,say $C_{3}H_{6}O$. Write their structures and name them. State the relation between the two in the language of science.

Which type of compound is ethyl acetate?

How is scum formed?

Name the reaction which is commonly used in the conversion of vegetable oils to fats. Explain the reaction involved in detail.