If milk changes into curd, is it a chemical, reversible or a fast change ?

Milk is converted into curd by :

Rusting of iron is a chemical change.

Ripening of fruits is a chemical change

Sublimation is a chemical change

In a reversible adiabatic change Delta Q is

Explain energy changes in a chemical change.

Entropy change for an adiabatic reversible process is

Differentiate between Slow and fast changes

Cutting of paper into pieces is a chemical change.

Give a reason why- Freezing of water is a reversible change while burning of a candle an irreversible change.