Photosynthesis is an irreversible chemical change.
Important Questions on Physical And Chemical Changes
In this section, each question has two matching lists. Choices for the correct combination of elements from List-I and List-II are given as options (a), (b), (c) and (d) out of which one is correct.
| List-I | List-II |
| (P) Folding of paper | 1. Crystallisation |
| (Q) Zinc coating | 2. Cut apples |
| (R) Solid in pure form | 3. Can be reversed |
| (S) Oxidation | 4. Galvanisation |
In this section, each question has two matching lists. Choices for the correct combination of elements from List-I and List-II are given as options (a), (b), (c) and (d) out of which one is correct.
| List-I | List-II |
| (P) Iron nail + Copper sulphate | 1. Carbon dioxide |
| (Q) Vinegar + Baking soda | 2. Calcium carbonate |
| (R) Iron + Moisture + Air | 3. Displacement reaction |
| (S) Lime water + Carbon dioxide | 4. Rust |
In this section, each question has two matching lists. Choices for the correct combination of elements from List-I and List-II are given as options (a), (b), (c) and (d) out of which one is correct.
| List-I | List-II |
| (P) Chemical change | 1. Evolution of a gas |
| (Q) Physical change | 2. Pure solid |
| (R) Crystallisation | 3. Change in state |
| (S) Alloying | 4. Mixing in molten solids |
In this section, each question has two matching lists. Choices for the correct combination of elements from List-I and List-II are given as options (a), (b), (c) and (d) out of which one is correct.
| List-I | List-II |
| (P) Burning of coal | 1. Rusting |
| (Q) Painting of a surface | 2. Evaporation |
| (R) Dipping iron in water | 3. Chemical change |
| (S) Salt from sea water | 4. Prevention of rusting |
In this section, each question has two matching lists. Choices for the correct combination of elements from List-I and List-II are given as options (a), (b), (c) and (d) out of which one is correct.
| List-I | List-II |
| (P) Change in temperature | 1. Magnesium reacting with dilute sulphuric acid |
| (Q) Evolution of a gas | 2. Potassium iodide reacting with lead nitrate |
| (R) Formation of a precipitate | 3. Sulphur dioxide gas reacting with acidified potassium dichromate solution |
| (S) Change in colour | 4. Zinc granules reacting with dilute sulphuric acid |
