Q3. Answer the following questions in one sentence only. (5) 1) What do you obtain when water vapour is cooled? 2) Why is the curdling of milk known as an irreversible change? 3) What do we get by churning curd? 4) Give one example of two liquid mixtures in which the components do not mix with each other. 5) Is the melting of ice a reversible change or an irreversible change?
Answers
Answer:
when water vapour is cooled we get rain.
1) What do you obtain when water vapour is cooled?
We obtain water in its liquid form, which is rain, when water vapour is cooled. Water has three different states: solid, liquid and gas. Ice is the solid state of water while vapour is the gaseous state.
2) Why is the curdling of milk known as an irreversible change?
An irreversible change is the change in which a substance cannot be reversed back to its original form. When milk curdles, it cannot be changed back to milk hence it is an irreversible change.
3) What do we get by churning curd?
We get butter by churning curd. Churning is the process in which curd is shaken and stirred repeatedly using a machine or a manual method to make butter.
4) Give one example of two liquid mixtures in which the components do not mix with each other.
Oil and water is a good example. These are two liquids that do not mix with each other. Such liquids are called immiscible.
5) Is the melting of ice a reversible change or an irreversible change?
The melting of ice is a reversible change. A reversible change is a change that can be reversed back to its original form. When ice melts, it forms liquid water. If we keep this water in the refrigerator for a while, it gradually returns back to its original form: an ice.