(3) preventing rapid setting of cement Explanation: Portland cement clinker is a hydraulic material which shall consist of at least two-thirds by mass of calcium silicates, the remainder consisting of aluminium- and ironcontaining clinker phases and other compounds. The ratio of CaO to SiO2 shall not be less than 2.0. The magnesium oxide content (MgO) shall not exceed 5.0% by mass. Cement sets when mixed with water by way of a complex series of chemical reactions still only partly understood.

(3) preventing rapid setting of cement Explanation: Portland cement clinker is a hydraulic material which shall consist of at least two-thirds by mass of calcium silicates, the remainder consisting of aluminium- and ironcontaining clinker phases and other compounds. The ratio of CaO to SiO2 shall not be less than 2.0. The magnesium oxide content (MgO) shall not exceed 5.0% by mass. Cement sets when mixed with water by way of a complex series of chemical reactions still only partly understood.
by

1 Answer

Answer :

Milk is a colloidal system in which: (1) Water is dispersed in fat (2) Fat is dispersed in water (3) Fat and water are dispersed in each other (4) Fat is dissolved
by
selected

Related questions

(1) Calcium silicate and calcium alurninate Explanation: Portland cement is the most common type of cement in general use around the world because it is a basic ingredient of concrete, mortar, stucco and most non-specialty grout. It usually originates from limestone. It is a fine powder produced by grinding Portland cement. clinker (more than 90%), a limited amount of calcium sulfate (which controls the set time) and up to 5% minor constituents.

Description : (1) Calcium silicate and calcium alurninate Explanation: Portland cement is the most common type of cement in general use around the world because it is a basic ingredient of concrete, mortar, stucco ... limited amount of calcium sulfate (which controls the set time) and up to 5% minor constituents.

Last Answer : Milk is a colloidal system in which: (1) Water is dispersed in fat (2) Fat is dispersed in water (3) Fat and water are dispersed in each other (4) Fat is dissolved

Cement mainly contains (A) CaO, SiO2 , Al2O3 (B) MgO, SiO2 , K2O (C) Al2O3 , MgO, Fe2O3 (D) CaO, MgO, K2O

Description : Cement mainly contains (A) CaO, SiO2 , Al2O3 (B) MgO, SiO2 , K2O (C) Al2O3 , MgO, Fe2O3 (D) CaO, MgO, K2O

Last Answer : (A) CaO, SiO2 , Al2O3

The addition of gypsum to portland cement helps in : (1) increasing the strength of cement (2) rapid setting of cement (3) preventing rapid setting of cement (4) reduction in the cost of cement

Description : The addition of gypsum to portland cement helps in : (1) increasing the strength of cement (2) rapid setting of cement (3) preventing rapid setting of cement (4) reduction in the cost of cement

Last Answer : preventing rapid setting of cement

Portland cement consists mainly of (A) CaO & SiO2 (B) SiO2 & Al2O3 (C) CaO & Al2O3 (D) CaO & Fe2O3

Description : Portland cement consists mainly of (A) CaO & SiO2 (B) SiO2 & Al2O3 (C) CaO & Al2O3 (D) CaO & Fe2O3

Last Answer : (A) CaO & SiO2

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 (A) 5CaO. 3 Al2O3 (B) 3CaO. Al2O3 (C) 3CaO. SiO2 (D) 2CaO. SiO2

Description : 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 (A) 5CaO. 3 Al2O3 (B) 3CaO. Al2O3 (C) 3CaO. SiO2 (D) 2CaO. SiO2

Last Answer : Option A

Which of the following is an acidic constituent of B.F. slag? (A) SiO2 (B) FeO (C) MgO (D) CaO

Description : Which of the following is an acidic constituent of B.F. slag? (A) SiO2 (B) FeO (C) MgO (D) CaO

Last Answer : Option A

The slag which floats on the surface of the molten iron generally contains (A) Lime (CaO) 45% (B) Silica (SiO2) 35% (C) Alumina (Al2O3) 12% and MgO, CaSO4, KMnO2 and FeO 8% (D) All the above

Description : The slag which floats on the surface of the molten iron generally contains (A) Lime (CaO) 45% (B) Silica (SiO2) 35% (C) Alumina (Al2O3) 12% and MgO, CaSO4, KMnO2 and FeO 8% (D) All the above

Last Answer : Answer: Option D

The slag which floats on the surface of the molten iron generally contains (A) Lime (CaO) 45% (B) Silica (SiO2) 35% (C) Alumina (Al2O3) 12% and MgO, CaSO4, KMnO2 and FeO 8% (D) All these

Description : The slag which floats on the surface of the molten iron generally contains (A) Lime (CaO) 45% (B) Silica (SiO2) 35% (C) Alumina (Al2O3) 12% and MgO, CaSO4, KMnO2 and FeO 8% (D) All these

Last Answer : Answer: Option D

Portland cement manufactured from pure white chalk and clay but free from iron-oxide, is known as (A) Quick setting cement (B) Rapid hardening cement (C) White cement (D) Low heat Portland cement

Description : Portland cement manufactured from pure white chalk and clay but free from iron-oxide, is known as (A) Quick setting cement (B) Rapid hardening cement (C) White cement (D) Low heat Portland cement

Last Answer : Answer: Option C

Main constituents of Portland cement are calcium aluminate and (A) Gypsum(B) Silicates(C) Sodium silicate(D) Carbonates

Description : Main constituents of Portland cement are calcium aluminate and (A) Gypsum (B) Silicates (C) Sodium silicate (D) Carbonates

Last Answer : (B) Silicates

In Portland Blast furnace slag cement, the blast furnace slag content shall not exceed [ A ] 50% [ B ] 65% [ C ] 80% [ D ] 90%

Description : In Portland Blast furnace slag cement, the blast furnace slag content shall not exceed [ A ] 50% [ B ] 65% [ C ] 80% [ D ] 90%

Last Answer : [ B ] 65%

For an ordinary Portland cement (A) Residual does not exceed 10% when sieved through IS Sieve No. 9 (B) Soundness varies from 5 to 10 mm (C) Initial setting time is not less than 30 minutes (D) Compressive stress after 7 days, is not less than 175 kg/cm2

Description : For an ordinary Portland cement (A) Residual does not exceed 10% when sieved through IS Sieve No. 9 (B) Soundness varies from 5 to 10 mm (C) Initial setting time is not less than 30 minutes (D) Compressive stress after 7 days, is not less than 175 kg/cm2

Last Answer : (C) Initial setting time is not less than 30 minutes

According to IS Code , the requirement of an ordinary Portland cement is (a) The residue does not exceed 10% when sieved through is sieve no .9 (b) Its initial setting time is not less than 30 minutes. (c) its expansion is not morethan 10mm for unaerated cement (d) All the above.

Description : According to IS Code , the requirement of an ordinary Portland cement is (a) The residue does not exceed 10% when sieved through is sieve no .9 (b) Its initial setting time is not less than 30 minutes. (c) its expansion is not morethan 10mm for unaerated cement (d) All the above.

Last Answer : (d) All the above.

Asbestos (A) Is a natural fibrous mineral substance (B) Is composed of hydrous silicates of calcium and magnesium (CaSiO3, 3MgSiO3) (C) Contains iron oxide and alumina (D) All the above

Description : Asbestos (A) Is a natural fibrous mineral substance (B) Is composed of hydrous silicates of calcium and magnesium (CaSiO3, 3MgSiO3) (C) Contains iron oxide and alumina (D) All the above

Last Answer : Answer: Option D

Low grade phosphate rock can be used in electrical furnace, because (A) Of the better CaO/SiO2 balance for slag formation (B) CaO content is less (C) It is cheap (D) It produces low cost product

Description : Low grade phosphate rock can be used in electrical furnace, because (A) Of the better CaO/SiO2 balance for slag formation (B) CaO content is less (C) It is cheap (D) It produces low cost product

Last Answer : (A) Of the better CaO/SiO2 balance for slag formation

Setting of cement is due to the hydration of calcium silicates and?

Description : Setting of cement is due to the hydration of calcium silicates and?

Last Answer : Calcium aluminates

Which of the following is the second major component of cement? (A) Al2O3(B) SiO2(C) CaO(D) Fe2O3

Description : Which of the following is the second major component of cement? (A) Al2O3 (B) SiO2 (C) CaO (D) Fe2O3

Last Answer : (B) SiO2

For construction of structures in sea water, the cement generally preferred to, is (A) Portland-pozzolana cement (B) Quick setting cement (C) Low heat Portland cement (D) Rapid hardening cement

Description : For construction of structures in sea water, the cement generally preferred to, is (A) Portland-pozzolana cement (B) Quick setting cement (C) Low heat Portland cement (D) Rapid hardening cement

Last Answer : Answer: Option A

Which raw material is used to impart colour to the glass? a) Al2O3 b) CoO c) CaO d) MgO

Description : Which raw material is used to impart colour to the glass? a) Al2O3 b) CoO c) CaO d) MgO

Last Answer : b) CoO

The compound of Portland cement which reacts immediately with water and also sets first is (A) Tri-calcium silicate (B) Di-calcium silicate (C) Tri-calcium aluminate (D) Tetra calcium alumino ferrite

Description : The compound of Portland cement which reacts immediately with water and also sets first is (A) Tri-calcium silicate (B) Di-calcium silicate (C) Tri-calcium aluminate (D) Tetra calcium alumino ferrite

Last Answer : Answer: Option C

When compared to ordinary Portland cement, Rapid hardening Portland cement contains ______________ amount of lime content [ A ] Equal [ B ] Greater [ C ] Lesser [ D ] Zero

Description : When compared to ordinary Portland cement, Rapid hardening Portland cement contains ______________ amount of lime content [ A ] Equal [ B ] Greater [ C ] Lesser [ D ] Zero

Last Answer : [ B ] Greater

__________ is the major constituent of the Portland cement. (A) Calcium carbonate (B) Calcium oxide (C) Tricalcium silicate (D) Calcium sulphate

Description : __________ is the major constituent of the Portland cement. (A) Calcium carbonate (B) Calcium oxide (C) Tricalcium silicate (D) Calcium sulphate

Last Answer : (C) Tricalcium silicate

Pick up the correct statement from the following: (A) The free quartz suddenly expands at a temperature lower than 600°C (B) The lime stone resists fire upto about 800°C and at higher temperature it splits into CaO and CO2 (C) The sand stone with silicates resist a fire in a better way (D) All the above

Description : Pick up the correct statement from the following: (A) The free quartz suddenly expands at a temperature lower than 600°C (B) The lime stone resists fire upto about 800°C and at higher temperature it splits into ... (C) The sand stone with silicates resist a fire in a better way (D) All the above

Last Answer : Answer: Option D

Philosopher’s wool is chemically - (1) Aluminium oxide (2) Magnesium oxide (3) Zinc oxide (4) Calcium oxide

Description : Philosopher’s wool is chemically - (1) Aluminium oxide (2) Magnesium oxide (3) Zinc oxide (4) Calcium oxide

Last Answer : (3) Zinc oxide Explanation: Philosopher's Wool is chemically zinc oxide.

Philosopher’s wool is chemically (1) Aluminium oxide (2) Magnesium oxide (3) Zinc oxide (4) Calcium oxide

Description : Philosopher’s wool is chemically (1) Aluminium oxide (2) Magnesium oxide (3) Zinc oxide (4) Calcium oxide

Last Answer : Zinc oxide

Which one of the following is classified as a covalent network solid crystal? w) CaO x) SiO2 y) CO2 z) Pb

Description : Which one of the following is classified as a covalent network solid crystal? w) CaO x) SiO2 y) CO2 z) Pb

Last Answer : ANSWER: B -- SiO2

.The most resistant filling materials to fill class IV cavities are: A. Resins with silicone dioxide (SiO2) B. Resins with glass or quartz C. Silico-phosphate D. Silicates

Description : .The most resistant filling materials to fill class IV cavities are: A. Resins with silicone dioxide (SiO2) B. Resins with glass or quartz C. Silico-phosphate D. Silicates

Last Answer : B. Resins with glass or quartz

For mass concrete work, the type of cement preferable is [ A ] Ordinary Portland cement [ B ] Rapid hardening cement [ C ] Low heat cement [ D ] Blast furnace slag cement

Description : For mass concrete work, the type of cement preferable is [ A ] Ordinary Portland cement [ B ] Rapid hardening cement [ C ] Low heat cement [ D ] Blast furnace slag cement

Last Answer : [ C ] Low heat cement

Inside the ____ is a gas generator containing a mixture of NaN3 (Sodium Azide), KNO3 (Potassium Nitrate) and SiO2 (Silicon Dioxide). When the undesired event happens, an electric circuit is turned on by a sensor, and a series of chemical reactions generate nitrogen gas that fills ____ in 20 to 30 milliseconds. Fill up the blank

Description : Inside the ____ is a gas generator containing a mixture of NaN3 (Sodium Azide), KNO3 (Potassium Nitrate) and SiO2 (Silicon Dioxide). When the undesired event happens, an electric circuit is ... chemical reactions generate nitrogen gas that fills ____ in 20 to 30 milliseconds. Fill up the blank

Last Answer : Air-bags in automobiles.

What is the common name for calcium oxide, CaO?

Description : What is the common name for calcium oxide, CaO?

Last Answer : ANSWER: QUICKLIME (LIME)

More than 95% of __________ is present in corundum. (A) SiO2 (B) Al2O3 (C) CaSiO2 (D) MgO

Description : More than 95% of __________ is present in corundum. (A) SiO2 (B) Al2O3 (C) CaSiO2 (D) MgO

Last Answer : B) Al2O3

(3) Detergents give lather even with hard water Explanation: Soaps are made of materials found in nature. Detergents are synthetic a big drawback of washing with soap is that the minerals in water react with those in soap, leaving an insoluble film. Detergents react less to minerals in water and for all practical purposes are the product of choice for laundry, unless you have very soft water. On the other hand, soap will combine with the magnesium and calcium ions in hard water to create an insoluble residue that can clog drains and stick to clothing.

Description : (3) Detergents give lather even with hard water Explanation: Soaps are made of materials found in nature. Detergents are synthetic a big drawback of washing with soap is that the minerals in water ... ions in hard water to create an insoluble residue that can clog drains and stick to clothing.

Last Answer : What is the objective of the 'Kyoto Protocol'? (1) To abolish child labour (2) To eliminate nuclear weapons (3) To increase ground water levels (4) To reduce greenhouse gases

(3) Detergents give lather even with hard water Explanation: Soaps are made of materials found in nature. Detergents are synthetic. a big drawback of washing with soap is that the minerals in water react with those in soap, leaving an insoluble film. Detergents react less to minerals in water and for all practical purposes are the product of choice for laundry, unless you have very soft water. On the other hand, soap will combine with the magnesium and calcium ions in hard water to create an insoluble residue that can clog drains and stick to clothing.

Description : (3) Detergents give lather even with hard water Explanation: Soaps are made of materials found in nature. Detergents are synthetic. a big drawback of washing with soap is that the minerals in water ... ions in hard water to create an insoluble residue that can clog drains and stick to clothing.

Last Answer : Cement is usually a mixture of – (1) Calcium silicate and calcium alurninate (2) Calcium silicate and calcium ferrate (3) Calcium aluminate and calcium ferrate (4) Lime stone and silicon dioxide

Consider the following statements: Maximum slenderness ratio of load-bearing masonry walls for a dwelling having more than two storeys shall not exceed. 1. 12, if lime mortar is used 2. 18, if cement-lime mortar 1:2:9 is used 3. 24, if cement mortar 1:6 is used\ Which of these statements are correct? (a) 1 and 2 only b) 2 and 3 only c) 1 and 3 only d)1, 2 and 3

Description : Consider the following statements: Maximum slenderness ratio of load-bearing masonry walls for a dwelling having more than two storeys shall not exceed. 1. 12, if lime mortar is used 2. 18, if cement-lime mortar 1:2:9 is used 3. 24, ... ? (a) 1 and 2 only b) 2 and 3 only c) 1 and 3 only d)1, 2 and 3

Last Answer : b) 2 and 3 only

Pick out the wrong statement. (A) Dry process is used for the manufacture of cement, when the raw material is blast furnace slag (B) Portland cement is made employing wet process (C) Gypsum is added to Portland cement to lengthen its setting time (D) None of these

Description : Pick out the wrong statement. (A) Dry process is used for the manufacture of cement, when the raw material is blast furnace slag (B) Portland cement is made employing wet process (C) Gypsum is added to Portland cement to lengthen its setting time (D) None of these

Last Answer : (D) None of these

Ganister contains maximum percentage of (A) FeO (B) SiO2 (C) MgO

Description : Ganister contains maximum percentage of (A) FeO (B) SiO2 (C) MgO

Last Answer : (B) SiO2

9. Which of the following is an acidic constituent of B.F. slag? (A) SiO2 (B) FeO (C) MgO

Description : 9. Which of the following is an acidic constituent of B.F. slag? (A) SiO2 (B) FeO (C) MgO

Last Answer : Option A

The initial setting time for ordinary Portland cement as per IS specifications should not be less than (A) 10 minutes (B) 30 minutes (C) 60 minutes (D) 600 minutes

Description : The initial setting time for ordinary Portland cement as per IS specifications should not be less than (A) 10 minutes (B) 30 minutes (C) 60 minutes (D) 600 minutes

Last Answer : Answer: Option B

Pick out the wrong statement. (A) High early strength cement are made from materials having high silica to lime ratio (B) The function of gypsum in cement is to enhance its initial setting rate (C) Acid resistant cements are known as silicate cement (D) Major component of greyish Portland cement is tricalcium silicate

Description : Pick out the wrong statement. (A) High early strength cement are made from materials having high silica to lime ratio (B) The function of gypsum in cement is to enhance its initial ... cements are known as silicate cement (D) Major component of greyish Portland cement is tricalcium silicate

Last Answer : (A) High early strength cement are made from materials having high silica to lime ratio

Pick out the wrong statement. (A) Hard glass which is used for making laboratory glass wares is a mixture of sodium borosilicate and aluminium borosilicate (B) Glass is decolorized during its manufacture by adding antimony oxide, manganese dioxide or arsenic oxide (C) Ordinary glass is represented chemically by Na2O . CaO . 6SiO2 (D) Red color is imparted to glass by addition of arsenic oxide

Description : Pick out the wrong statement. (A) Hard glass which is used for making laboratory glass wares is a mixture of sodium borosilicate and aluminium borosilicate (B) Glass is decolorized during its manufacture by ... Na2O . CaO . 6SiO2 (D) Red color is imparted to glass by addition of arsenic oxide

Last Answer : (D) Red color is imparted to glass by addition of arsenic oxide

How many of the following liberate `O_(2)` on heating in a dry test tube ? `CaO, Fe_(2)O_(3), Fe_(3)O_(4), FeO, Cr_(2)O_(3), XeF_(4), Al_(2)O_(3), MgO

Description : How many of the following liberate `O_(2)` on heating in a dry test tube ? `CaO, Fe_(2)O_(3), Fe_(3)O_(4), FeO, Cr_(2)O_(3), XeF_(4), Al_(2)O_(3), MgO

Last Answer : How many of the following liberate `O_(2)` on heating in a dry test tube ? `CaO, Fe_(2)O_(3), Fe_(3)O_(4), ... 3), XeF_(4), Al_(2)O_(3), MgO, Na_(2)O`

State the type of chemical reactions and chemical equations that take place in the following: (i) Magnesium wire is burnt in air. (ii) Electric current is passed through water. (iii) Ammonia and hydrogen chloride gases’are mixed. -Chemistry

Description : State the type of chemical reactions and chemical equations that take place in the following: (i) Magnesium wire is burnt in air. (ii) Electric current is passed through water. (iii) Ammonia and hydrogen chloride gases’are mixed. -Chemistry

Last Answer : This is the Answer:

Write balanced chemical equations for the following word equations: (a) Iron + Chlorine → Iron (III) chloride (b) Magnesium + dil sulphuric acid → Magnesium sulphate + water (c) Magnesium + oxygen → Magnesium oxide (d) Calcium oxide + water → Calcium hydroxide (e) Sodium + chlorine → Sodium chloride

Description : Write balanced chemical equations for the following word equations: (a) Iron + Chlorine → Iron (III) chloride (b) Magnesium + dil sulphuric acid → Magnesium sulphate + water (c) Magnesium + oxygen → ... oxide (d) Calcium oxide + water → Calcium hydroxide (e) Sodium + chlorine → Sodium chloride

Last Answer : (a) Iron + Chlorine → Iron (III) chloride 4Fe + 3Cl2 → 2F2Cl3 (b) Magnesium + dil sulphuric acid → Magnesium sulphate + water 2Mg + 2H2SO4 → 2MgSO4 + 2H2 (c) Magnesium + oxygen → Magnesium oxide 2Mg ... hydroxide CaO + H2O → Ca(OH)2 (e) Sodium + chlorine → Sodium chloride 2Na + Cl2 → 2NaCl

Setting time of cement increases by adding (A) Gypsum (B) Hydrogen peroxide (C) Calcium chloride (D) Sodium oxide

Description : Setting time of cement increases by adding (A) Gypsum (B) Hydrogen peroxide (C) Calcium chloride (D) Sodium oxide

Last Answer : Answer: Option A

Setting time of cement increases by adding (i)gypsum (ii)sodium oxide (iii)calcium chloride [ A ] i [ B ] i and ii [ C ] i and iii [ D ] i, ii and iii

Description : Setting time of cement increases by adding (i)gypsum (ii)sodium oxide (iii)calcium chloride [ A ] i [ B ] i and ii [ C ] i and iii [ D ] i, ii and iii

Last Answer : [ A ] i

Which on of the following statements regarding the Departmental Committee of the Parliament of Q.In)ia on the empowerment of women is correct? (1) The Committee will consist of members of the Lok Sabha only (2) A Cabinet Minister can be a member of the Committees (3) The term of office of the members of the Committee shall not exceed two years (4) It reports on the working of welfare programmes for the women

Description : Which on of the following statements regarding the Departmental Committee of the Parliament of Q.In)ia on the empowerment of women is correct? (1) The Committee will consist of members of the Lok Sabha ... shall not exceed two years (4) It reports on the working of welfare programmes for the women

Last Answer : (4) It reports on the working of welfare programmes for the women Explanation: The Committee on Empowerment of Women was constituted on 29th April 1997. The Committee consists of 30 Members of whom ... functions of the committee is to report on the working of the welfare programmes for the women.

The cement whose strength is a little lower than the ordinary cement during the first three months but attains afterwards the same strength, is known as (A) Low-heat Portland cement (B) Rapid hardening Portland cement (C) Portland blast slag cement (D) Portland pozzolana cement

Description : The cement whose strength is a little lower than the ordinary cement during the first three months but attains afterwards the same strength, is known as (A) Low-heat Portland cement (B) Rapid hardening Portland cement (C) Portland blast slag cement (D) Portland pozzolana cement

Last Answer : Answer: Option A

Antacid combinations of magnesium and aluminium salts are superior to single component preparations because: A. They have rapid as well as sustained acid neutralizing action B. They are less likely to affect gastric emptying C. They are less likely to alter bowel movement D. All of the above

Description : Antacid combinations of magnesium and aluminium salts are superior to single component preparations because: A. They have rapid as well as sustained acid neutralizing action B. They are less likely to affect gastric emptying C. They are less likely to alter bowel movement D. All of the above

Last Answer : D. All of the above

Antacid tablets consist of – (1) Hydroxides of sodium, magnesium and aluminium (2) Hydroxides of magnesium and aluminium (3) Hydroxides of sodium and aluminium (4) Hydroxides of magnesium and sodium

Description : Antacid tablets consist of – (1) Hydroxides of sodium, magnesium and aluminium (2) Hydroxides of magnesium and aluminium (3) Hydroxides of sodium and aluminium (4) Hydroxides of magnesium and sodium

Last Answer : (2) Hydroxides of magnesium and aluminium Explanation: An antacid is a base which neutralizes stomach acidity. The most common of these bases are hydroxides, carbonates, or bicarbonates such as Aluminum hydroxide, Calcium. carbonate, Magnesium carbonate, Magnesium hydroxide, and Sodium bicarbonate.

Antacid tablets consist of (1) Hydroxides of sodium, magnesium and aluminium (2) Hydroxides of magnesium and aluminium (3) Hydroxides of sodium and aluminium (4) Hydroxides of magnesium and sodium

Description : Antacid tablets consist of (1) Hydroxides of sodium, magnesium and aluminium (2) Hydroxides of magnesium and aluminium (3) Hydroxides of sodium and aluminium (4) Hydroxides of magnesium and sodium

Last Answer : Hydroxides of magnesium and aluminium