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In the average composition of portland cement, the percentage of magnesium oxide is a ___________

In the average composition of portland cement, the percentage of magnesium oxide is a ___________ Correct Answer 2 to 3%

Cement is an important building material. The average composition of portland cement is calcium oxide of 50 to 60%, Silicon dioxide of 20 to 25%, aluminium oxide of 5 to 10%, magnesium oxide of 2 to 3%, ferric oxide of 1 to 2% and sulphur trioxide of 1 to 2%.

Related Questions

An alloy of zinc, magnesium, and copper contains 80% of copper, 15% of zinc, and 5% of magnesium. The second alloy of copper and magnesium only is melted with the first and the mixture contains 75% of copper, 5% of zinc and 20% of magnesium. What is the percentage of magnesium in the second alloy?
Alumina, silica, lime and iron oxide are the basic raw material for the manufacture of portland cement. The component of Portland cement which first hardens is
Consider the following statements : (1) Tests on cement paste to determine initial and final setting times are done at 0.85 times normal consistency conditions. (2) Low heat cement has a high percentage of tri-calcium aluminate. (3) High early strength Portland cement contains a large percentage of tricalcium silicate and lower percentage of dicalcium silicate. Which of these statements are correct ?
A shopkeeper earns a profit of 15% if he mixes 85 kg of A-type cement with 35 kg of B-type cement and sells the mixture at Rs. 46 per kg. He can increase his profit to 25% if he mixes 65 kg of A-type cement with 35 kg of B-type cement and sells the mixture at Rs. 46.5 per kg. At what price should he sell a mixture of 30 kg A-type cement and 50 kg B-type cement to earn a profit of 75%?
A construction company purchases cement at the rate of Rs. 1,000 per tonne and stores it at Rs. 100 per tonne. It is perceived that in the coming month, the price of cement will rise by Rs. 2,000 per tonne. The company already has 500 tonnes of cement. If the cement usage during a month is 1,000 tonnes, how much cement should the company purchase this month to minimize its expense in the next one?
Consider the following statements: 1) Hydrophobic cement grains possess the low wetting ability 2) Rapid-hardening cement is useful in concreting under static, or running water 3) Quick-setting cement helps the concrete to attain high strength in the initial period 4) White cement is just a variety of ordinary cement-free of coloring oxides. Which of the above statements are correct?
The percentage composition of alumina in Portland cement is ___________
Consider the following statements regarding 'setting of cement': 1. Low-heat cement sets faster than OPC. 2. Final setting time decides the strength of cement. 3. Initial setting time of Portland PozzoIlona is 30 minutes. 4. Air-induced setting is observed when stored under damp conditions. 5. Addition of gypsum retards the setting time. Which of the above statements are correct?
Questions below followed by three quantities. Find the relationship between them. Quantity I: In a class with a certain number of students if a teacher weighing 78 kg is added, then average weight of class is increased by 2 kg. If one more teacher weighing 66 kg is added, then the average weight of the class increases by 3.5 kg over the original average. What is the original average weight (in kg) of the class? Quantity II: The average age of 16 students and their teacher's age is 16 years. If the teacher's age is excluded, the average reduces by 2. What is the teacher's age? Quantity III: Average weight of three friends A, B and C is 46 kg. Another person D joins the group and now the average is 45 kg. If another person E whose weight is 6 kg more than D, joins the group replacing A, then average weight of B, C, D and E becomes 47 kg. What is the weight of A (in kg)?
Which type of cement is produced by grinding clinkers formed by calcining bauxite, lime, iron oxide with a little ferric oxide, silica magnesia, etc? (Note that alumina content in this type of cement should NOT be less than 32%.)