In good quality cement ratio of lime total oxides of Si(SiO\(_2\)), Aluminium(Al\(_2\)O\(_3\)) and Iron(Fe\(_2\)O\(_3\)) should be as close as possible to _____ .
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For high-quality cement, the lime to oxide ratio must be within the range of 1.9–2.1, ensuring good binding properties and durability
Correct Answer: 2
Solution and Explanation
Assessment of Cement Quality:
The quality of cement is assessed based on the ratio of lime (CaO) to the sum of oxides (SiO2, Al2O3, and Fe2O3). The formula for this ratio is:
Ratio = \(\frac{\% \text{CaO}}{\% \text{SiO}_2 + \% \text{Al}_2\text{O}_3 + \% \text{Fe}_2\text{O}_3}\)
For good quality cement, this ratio lies in the range of 1.9 to 2.1, which ensures the proper strength and binding properties of the cement. If the ratio deviates significantly:
- Higher ratio: May make the cement weak in resistance to environmental effects.
- Lower ratio: May reduce the binding efficiency and durability of the cement.
Conclusion: Since the ratio is closest to 2, the correct answer is 2.
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P-Block Elements
- P block elements are those in which the last electron enters any of the three p-orbitals of their respective shells. Since a p-subshell has three degenerate p-orbitals each of which can accommodate two electrons, therefore in all there are six groups of p-block elements.
- P block elements are shiny and usually a good conductor of electricity and heat as they have a tendency to lose an electron. You will find some amazing properties of elements in a P-block element like gallium. It’s a metal that can melt in the palm of your hand. Silicon is also one of the most important metalloids of the p-block group as it is an important component of glass.
P block elements consist of:
- Group 13 Elements: Boron family
- Group 14 Elements: Carbon family
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- Group 16 Elements: Oxygen family
- Group 17 Elements: Fluorine family
- Group 18 Elements: Neon family