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Assertion: When cement is mixed with wat...

Assertion: When cement is mixed with water and left as such, it becomes hard mass.
Reason: Setting of cement is exothermic process.

A

If both Assertion & Reason are True & the Reason is a correct explanation of the Assertion

B

If both Assertion & Reason are True but Reason is not a correct explanation of the Assertion

C

If Assertion is True but the Reason is False

D

If both Assertion & Reason are False

Text Solution

AI Generated Solution

The correct Answer is:
**Step-by-Step Text Solution:** 1. **Understanding the Assertion**: The assertion states that when cement is mixed with water and left as such, it becomes a hard mass. This is true because the process of hydration occurs when cement is mixed with water. 2. **Hydration Reaction**: When water is added to cement, a chemical reaction known as hydration takes place. This reaction involves the combination of water with the compounds in cement, leading to the formation of various hydration products that contribute to the hardening process. 3. **Setting of Cement**: As the hydration reaction proceeds, the cement mixture begins to harden and gain strength. This is a crucial property of cement that allows it to be used in construction. 4. **Understanding the Reason**: The reason provided states that the setting of cement is an exothermic process. This is also true because during the hydration reaction, heat is released. An exothermic reaction is characterized by the release of heat, which occurs in this case. 5. **Evaluating the Relationship**: While both the assertion and the reason are true, we need to determine if the reason is the correct explanation for the assertion. The assertion explains that cement hardens due to hydration, while the reason explains that the process is exothermic. The exothermic nature of the reaction contributes to the process but does not directly explain why cement becomes hard. 6. **Conclusion**: Therefore, the correct conclusion is that both the assertion and reason are true, but the reason is not the correct explanation of the assertion. **Final Answer**: The correct option is: Both assertion and reason are true, but the reason is not the correct explanation of the assertion. ---
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Cement is one of the most important building material of the present time. It is a dirty greyish heavy powder containing calcium aluminates and silicates. The important raw materials neede for the manufacture of cement are limestone, clay and gypsum. the main step in the manufacture of cement is the heating of raw meal or slurru in the rotary kiln at a very high temperature 1400-1600^(@)C . Finally 2% or 3% gypsum is added. When cement is mixed with water and left as such for sometime, it becomes a hard mass. This is known as setting of cement. It is believed that varous aluminates and silicates present in the cement form hydrates with water which seperate in the form of gel. the gel formed start losing water partly by evaporation and partly by forming hydrates with unhydrated constituents. this results in the formation of a hard mass. Setting of cement is

Cement is one of the most important building material of the present time. It is a dirty greyish heavy powder containing calcium aluminates and silicates. The important raw materials neede for the manufacture of cement are limestone, clay and gypsum. the main step in the manufacture of cement is the heating of raw meal or slurru in the rotary kiln at a very high temperature 1400-1600^(@)C . Finally 2% or 3% gypsum is added. When cement is mixed with water and left as such for sometime, it becomes a hard mass. This is known as setting of cement. It is believed that varous aluminates and silicates present in the cement form hydrates with water which seperate in the form of gel. the gel formed start losing water partly by evaporation and partly by forming hydrates with unhydrated constituents. this results in the formation of a hard mass. Portland cement does not contain

Cement is one of the most important building material of the present time. It is a dirty greyish heavy powder containing calcium aluminates and silicates. The important raw materials neede for the manufacture of cement are limestone, clay and gypsum. the main step in the manufacture of cement is the heating of raw meal or slurru in the rotary kiln at a very high temperature 1400-1600^(@)C . Finally 2% or 3% gypsum is added. When cement is mixed with water and left as such for sometime, it becomes a hard mass. This is known as setting of cement. It is believed that varous aluminates and silicates present in the cement form hydrates with water which seperate in the form of gel. the gel formed start losing water partly by evaporation and partly by forming hydrates with unhydrated constituents. this results in the formation of a hard mass. Gypsum is added to portland cement

Cement is one of the most important building material of the present time. It is a dirty greyish heavy powder containing calcium aluminates and silicates. The important raw materials neede for the manufacture of cement are limestone, clay and gypsum. the main step in the manufacture of cement is the heating of raw meal or slurru in the rotary kiln at a very high temperature 1400-1600^(@)C . Finally 2% or 3% gypsum is added. When cement is mixed with water and left as such for sometime, it becomes a hard mass. This is known as setting of cement. It is believed that varous aluminates and silicates present in the cement form hydrates with water which seperate in the form of gel. the gel formed start losing water partly by evaporation and partly by forming hydrates with unhydrated constituents. this results in the formation of a hard mass. Concrete is a mixture of

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