Rohan tore a sheet of paper into pieces and then burnt them. Identify ...
Ansewr is c.both tearing and burning pieces because if you have teared the paper you may join it with glue or tape but it will not be as like it was before so this one is irreversible change . And secondly, if you burnt those pieces they canot be changed as they were before.
Rohan tore a sheet of paper into pieces and then burnt them. Identify ...
Tearing the sheet into pieces:
Tearing a sheet of paper into pieces is a physical change. It involves breaking the paper into smaller fragments without altering its chemical composition. The pieces can still be rearranged or glued back together to form the original sheet, indicating that the change is reversible.
Burning the pieces:
Burning the torn paper pieces, on the other hand, is an irreversible change. It involves a chemical reaction known as combustion, which leads to the formation of new substances. When paper is burnt, it undergoes a process called oxidation, where it reacts with oxygen in the air to produce carbon dioxide, water vapor, and ash. The carbon atoms in the paper combine with the oxygen atoms to form carbon dioxide, while the hydrogen atoms combine with oxygen to form water vapor. The remaining solid residue, called ash, is composed of the impurities present in the paper.
Both tearing and burning the pieces:
While tearing the sheet into pieces is a physical change that can be reversed, burning the torn paper pieces is a chemical change that cannot be reversed. Therefore, the irreversible change in this process occurs when the torn paper pieces are burned.
Conclusion:
The correct answer is option 'C' - both tearing and burning the pieces. Tearing the sheet into pieces is a physical change, while burning the pieces is a chemical change. The act of burning causes a permanent alteration in the composition of the paper, making it an irreversible change.
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