Question

Why is curdling of milk a chemical change?

Answer 1

Milk is a nutrient-dense liquid food produced by animals' mammary glands. It is the major source of nourishment for young animals, including breastfed human newborns who have not yet developed the ability to digest solid food. Colostrum is a kind of early-lactation milk that includes antibodies that improve the immune system and thereby lower the risk of numerous illnesses. It also contains a variety of other nutrients, including protein and lactose. Milk eating across species is frequent, especially among humans, who drink the milk of other animals.

Complete answer:
A physical alteration is one that alters the form, size, color, or texture of a material while leaving its chemical characteristics the same. Consider the case of ice melting. Because they may be reversed or altered back to its original substance, they are also known as reversible alterations. For instance, when ice melts, it turns into water, which is a physical change. This is even reversible because the water may freeze back to ice.
A chemical change is described as a change in a substance's chemical makeup that happens when it occurs. It leads to the creation of completely new compounds. Take, for example, food digestion.
These are usually irreversible alterations since they result in the development of a wholly new material that cannot be returned to its previous state. For example, food that has been digested cannot be recovered.
We are given a process called "curdling of milk," and we must determine if the change is chemical or physical.
We all know that curdling refers to the process of turning milk into curd. Let's have a look at how this conversion takes place.
To make curd, we boil milk and add a spoonful of curd to act as an inoculum. Curd contains lactic acid, as we all know. Casein protein is found in milk, and it interacts with lactic acid.
Lactic acid breaks down the milk's chemical structures/bonds and creates new ones, resulting in curd, a semi-solid form of milk. Throughout the procedure, we saw that the interaction between lactic acid and milk entailed the breakdown and formation of new bonds. As a result, it is connected with a chemical change, and hence this change is a chemical change. As a result, curdling milk is a chemical transformation.

Note:
Chemical changes are irreversible, as we all know. We can also answer the aforementioned question using this fact. Curd cannot be turned back to milk after it has been produced, therefore it is an irreversible process. As a result, it's a chemical alteration. So, anytime you're unsure about a change, check to see whether the original material can be retrieved.