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

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

1 Answer

Answer :

Answer: Option A
by

Related questions

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

The most commonly used admixture which prolongs the setting and hardening time is (A) Gypsum (B) Calcium chloride (C) Sodium silicate (D) All of the above

Description : The most commonly used admixture which prolongs the setting and hardening time is (A) Gypsum (B) Calcium chloride (C) Sodium silicate (D) All of the above

Last Answer : (A) Gypsum

Quick setting cement is produced by adding (A) Less amount of gypsum in very fine powdered form (B) More amount of gypsum in very fine powdered form (C) Aluminium sulphate in very fine powdered form (D) Pozzolana in very fine powdered form

Description : Quick setting cement is produced by adding (A) Less amount of gypsum in very fine powdered form (B) More amount of gypsum in very fine powdered form (C) Aluminium sulphate in very fine powdered form (D) Pozzolana in very fine powdered form

Last Answer : Answer: Option C

To retard the initial setting time of cement, the compound responsible, is (A) Tri-calcium silicate (B) Gypsum (C) Di-calcium silicate (D) Tri-calcium aluminate

Description : To retard the initial setting time of cement, the compound responsible, is (A) Tri-calcium silicate (B) Gypsum (C) Di-calcium silicate (D) Tri-calcium aluminate

Last Answer : Answer: Option B

The most commonly used retarder in cement is (A) Gypsum (B) Calcium chloride (C) Calcium carbonate (D) None of the above

Description : The most commonly used retarder in cement is (A) Gypsum (B) Calcium chloride (C) Calcium carbonate (D) None of the above

Last Answer : Answer: Option A

The effect of adding calcium chloride in concrete is (i) To increase shrinkage (ii) To decrease shrinkage (iii) To increase setting time (iv) To decrease setting time The correct answer is (A) (i) and (iii) (B) (i) and (iv) (C) (ii) and (iii) (D) (ii) and (iv)

Description : The effect of adding calcium chloride in concrete is (i) To increase shrinkage (ii) To decrease shrinkage (iii) To increase setting time (iv) To decrease setting time The correct answer is (A) (i) and (iii) (B) (i) and (iv) (C) (ii) and (iii) (D) (ii) and (iv)

Last Answer : (B) (i) and (iv)

Write the molecular formulae of: 1. Copper oxide 2. Iron (III) chloride 3. Sodium hydroxide 4. Iron (II) sulphide 5. Lead (II) oxide 6. Hydrogen nitrate (nitric acid) 7. Hydrogen sulphate (sulphuric acid) 8. Calcium hydroxide 9. Magnesium carbonate 10.Ammonium carbonate

Description : Write the molecular formulae of: 1. Copper oxide 2. Iron (III) chloride 3. Sodium hydroxide 4. Iron (II) sulphide 5. Lead (II) oxide 6. Hydrogen nitrate (nitric ... Hydrogen sulphate (sulphuric acid) 8. Calcium hydroxide 9. Magnesium carbonate 10.Ammonium carbonate

Last Answer : 1. Copper oxide - CuO 2. Iron (III) chloride - FeCl3 3. Sodium hydroxide - NaOH 4. Iron (II) sulphide - FeS 5. Lead (II) oxide - PbO 6. Hydrogen nitrate (nitric acid) - HNO3 7. ... ) - H2SO4 8. Calcium hydroxide - Ca(OH)2 9. Magnesium carbonate - MgCO3 10.Ammonium carbonate - (NH4)2CO3

The Most common admixture used to accelerate the initial setting of concrete is a) Gypsum b) Calcium chloride* c) Calcium carbonate d) Calcium bicarbonate

Description : The Most common admixture used to accelerate the initial setting of concrete is a) Gypsum b) Calcium chloride* c) Calcium carbonate d) Calcium bicarbonate

Last Answer : b) Calcium chloride*

Gypsum is chemically (A) Calcium chloride (B) Potassium sulphate (C) Sodium sulphate (D) Calcium sulphate

Description : Gypsum is chemically (A) Calcium chloride (B) Potassium sulphate (C) Sodium sulphate (D) Calcium sulphate

Last Answer : (D) Calcium sulphate

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

Which of the following compounds is commonly used as an antiseptic in mouthwashes and toothpastes? (1) Borax (2) Saltpetre (3) Hydrogen peroxide (4) Sodium chloride

Description : Which of the following compounds is commonly used as an antiseptic in mouthwashes and toothpastes? (1) Borax (2) Saltpetre (3) Hydrogen peroxide (4) Sodium chloride

Last Answer : (4) Sodium chloride Explanation: Antiseptics are antimicrobial substances that are applied to living tissue/skin to reduce the possibility of infection, sepsis, or putrefaction. Antiseptics are generally ... the body, and from disinfectants, which destroy microorganisms found on non-living objects.

Which of the following compounds is commonly used as an antiseptic in mouthwashes and toothpastes ? (1) Borax (2) Saltpetre (3) Hydrogen peroxide (4) Sodium chloride

Description : Which of the following compounds is commonly used as an antiseptic in mouthwashes and toothpastes ? (1) Borax (2) Saltpetre (3) Hydrogen peroxide (4) Sodium chloride

Last Answer : Sodium chloride

The gypsum is added to the cement for (a) Providing high strength to the cement (b) Controlling the initial setting time of cement. (c) Lowering the clinkering temp of cement (d) All the above.

Description : The gypsum is added to the cement for (a) Providing high strength to the cement (b) Controlling the initial setting time of cement. (c) Lowering the clinkering temp of cement (d) All the above.

Last Answer : (b) Controlling the initial setting time of cement.

(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.

Description : (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 ... mixed with water by way of a complex series of chemical reactions still only partly understood.

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

Pick up the correct statement from the following: (A) Calcium chloride acts as a retarder (B) Calcium chloride acts as an accelerator (C) Gypsum (calcium sulphate) acts as a retarder (D) Both (b) and (c)

Description : Pick up the correct statement from the following: (A) Calcium chloride acts as a retarder (B) Calcium chloride acts as an accelerator (C) Gypsum (calcium sulphate) acts as a retarder (D) Both (b) and (c)

Last Answer : (D) Both (b) and (c)

The most common admixture which is used to accelerate the initial set of concrete is (A) Gypsum (B) Calcium chloride (C) Calcium carbonate (D) None of the above

Description : The most common admixture which is used to accelerate the initial set of concrete is (A) Gypsum (B) Calcium chloride (C) Calcium carbonate (D) None of the above

Last Answer : Answer: Option B

Early attainment of strength in rapid hardening cement is mainly due to (A) Gypsum (B) Finer grinding (C) Tri-calcium silicate (D) Tri-calcium aluminate

Description : Early attainment of strength in rapid hardening cement is mainly due to (A) Gypsum (B) Finer grinding (C) Tri-calcium silicate (D) Tri-calcium aluminate

Last Answer : Answer: Option B

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

Sodium chloride, potassium chloride, magnesium oxide are examples of molecules with (a) Covalent bonding (b) Ionic bonding (c) Metallic bonding (d) Hydrogen bonding

Description : Sodium chloride, potassium chloride, magnesium oxide are examples of molecules with (a) Covalent bonding (b) Ionic bonding (c) Metallic bonding (d) Hydrogen bonding

Last Answer : Ans:(b)

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

How does the setting of cement takes place & what is the role of gypsum in setting of cement ?

Description : How does the setting of cement takes place & what is the role of gypsum in setting of cement ?

Last Answer : Ans When mixed with water, the setting of cement takes place to give a hard mass. This is due to the hydration of the molecules of the constituents and their Rearrangement. The purpose of adding gypsum is only to slow down the process of setting of the cement so that it gets sufficiently hardened.

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

The function of gypsum addition during cement making is to (A) Increase the density of cement (B) Decrease the cement setting rate (C) Both (A) and (B) (D) Neither (A) nor (B)

Description : The function of gypsum addition during cement making is to (A) Increase the density of cement (B) Decrease the cement setting rate (C) Both (A) and (B) (D) Neither (A) nor (B)

Last Answer : (B) Decrease the cement setting rate

A slow setting cement will have higher percentage of a) tricalcium aluminate b) tricalcium silicate c) Gypsum d) Dicalcium silicate*

Description : A slow setting cement will have higher percentage of a) tricalcium aluminate b) tricalcium silicate c) Gypsum d) Dicalcium silicate*

Last Answer : C2s

How does the setting of cement takes place & what is the role of gypsum in setting of cement ?

Description : How does the setting of cement takes place & what is the role of gypsum in setting of cement ?

Last Answer : When mixed with water, the setting of cement takes place to give a hard mass. This is due to the hydration of the molecules of the constituents and their rearrangement. The purpose of adding gypsum is only to slow down the process of setting of the cement so that it gets sufficiently hardened. 

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

Workability improved by adding (A) Fly ash (B) Hydrated lime (C) Calcium chloride (D) All the above

Description : Workability improved by adding (A) Fly ash (B) Hydrated lime (C) Calcium chloride (D) All the above

Last Answer : Answer: Option D

Select the incorrect statement (A) Lean mixes bleed more as compared to rich ones. (B) Bleeding can be minimized by adding pozzolana finer aggregate (C) Bleeding can be increased by addition 'of calcium chloride (D) None of the above

Description : Select the incorrect statement (A) Lean mixes bleed more as compared to rich ones. (B) Bleeding can be minimized by adding pozzolana finer aggregate (C) Bleeding can be increased by addition 'of calcium chloride (D) None of the above

Last Answer : Answer: Option D

The workability of concrete can be improved by adding (a) Hydrated lime (b) Fly ash (c) Calcium chloride (d) All the above

Description : The workability of concrete can be improved by adding (a) Hydrated lime (b) Fly ash (c) Calcium chloride (d) All the above

Last Answer : (d) All the above

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

Write the molecular formula for the oxide and sulphide of following elements. (a) Sodium (b) Calcium (c) Hydrogen

Description : Write the molecular formula for the oxide and sulphide of following elements. (a) Sodium (b) Calcium (c) Hydrogen

Last Answer : (a) Sodium oxide Na2O Sodium sulphide Na2S (b) Calcium oxide CaO Calcium sulphide CaS (c) Hydrogen oxide H2O Hydrogen sulphide H2S

Initial setting of cement is caused due to (A) Tri-calcium silicate (B) Di-calcium silicate (C) Tri-calcium aluminate (D) Tetra calcium alumino ferrite

Description : Initial setting of cement is caused due to (A) Tri-calcium silicate (B) Di-calcium silicate (C) Tri-calcium aluminate (D) Tetra calcium alumino ferrite

Last Answer : Answer: Option C

The main constituent of cement which is responsible for initial setting of cement is (A) Di-calcium silicate (B) Tri-calcium silicate (C) Tri-calcium aluminate (D) All of the above

Description : The main constituent of cement which is responsible for initial setting of cement is (A) Di-calcium silicate (B) Tri-calcium silicate (C) Tri-calcium aluminate (D) All of the above

Last Answer : Answer: Option C

The maximum quantity of calcium chloride used as an accelerator in cement in percentage by weight of cement is (A) 1 (B) 2 (C) 3 (D) 4

Description : The maximum quantity of calcium chloride used as an accelerator in cement in percentage by weight of cement is (A) 1 (B) 2 (C) 3 (D) 4

Last Answer : Answer: Option B

Setting time of cement is controlled by adding?

Description : Setting time of cement is controlled by adding?

Last Answer : Gypsum

Cement paints usually (A) Contain hydrated lime (B) Contain 5% to 10% colour pigments (C) Contain 5% sodium chloride (D) All the above

Description : Cement paints usually (A) Contain hydrated lime (B) Contain 5% to 10% colour pigments (C) Contain 5% sodium chloride (D) All the above

Last Answer : Answer: Option D

Pick up the correct statement from the following: (A) The lime in excess makes the cement unsound and causes the cement to expand and disintegrate (B) The silica in excess makes the cement stronger but its setting time also increases (C) The excess amount of alumina weakens the cement (D) All the above

Description : Pick up the correct statement from the following: (A) The lime in excess makes the cement unsound and causes the cement to expand and disintegrate (B) The silica in excess makes the cement stronger ... time also increases (C) The excess amount of alumina weakens the cement (D) All the above

Last Answer : Answer: Option D

High temp_______________the setting time of cement in concrete (a) Increases (b) Decreases (c) No effect (d) None of these

Description : High temp_______________the setting time of cement in concrete (a) Increases (b) Decreases (c) No effect (d) None of these

Last Answer : (b) Decreases

The impurity of mixing water which affects the setting time and strength of concrete, is (A) Sodium sulphates (B) Sodium chlorides (C) Sodium carbonates and bicarbonates (D) Calcium bicarbonates

Description : The impurity of mixing water which affects the setting time and strength of concrete, is (A) Sodium sulphates (B) Sodium chlorides (C) Sodium carbonates and bicarbonates (D) Calcium bicarbonates

Last Answer : Answer: Option C

Which of the following is the primary reason for adding calcium carbonate to the reduction process of iron oxide ores ? The calcium carbonate: w) acts as an oxidizing agent x) removes silicate waste products y) acts as a reducing agent z) removes sulfur waste products

Description : Which of the following is the primary reason for adding calcium carbonate to the reduction process of iron oxide ores ? The calcium carbonate: w) acts as an oxidizing agent x) removes silicate waste products y) acts as a reducing agent z) removes sulfur waste products

Last Answer : ANSWER: X -- REMOVES SILICATE WASTE PRODUCTS

Which one of the following is used to restore the colour of old oil-paintings? (1) Ozone (2) Hydrogen peroxide (3) Barium peroxide (4) Sodium peroxide

Description : Which one of the following is used to restore the colour of old oil-paintings? (1) Ozone (2) Hydrogen peroxide (3) Barium peroxide (4) Sodium peroxide

Last Answer : (2) Hydrogen peroxide Explanation: Hydrogen peroxide (H2O2) is the simplest peroxide (a compound with an oxygenoxygen single bond). It is also a strong oxidizer. Hydrogen peroxide is a clear ... capacity of hydrogen peroxide is so strong that it is considered a highly reactive oxygen species.

Which one of the following is used to restore the colour of old oilpaintings ? (1) Ozone (2) Hydrogen peroxide (3) Barium peroxide (4) Sodium peroxide

Description : Which one of the following is used to restore the colour of old oilpaintings ? (1) Ozone (2) Hydrogen peroxide (3) Barium peroxide (4) Sodium peroxide

Last Answer : Hydrogen peroxide

The obturating material of choice for primary teeth following complete pulpectomy is, A. Zn phosphate cement and formcresol combination paste B. Quick setting hydroxide cement C. Zinc oxide and eugenol cement D. Gutta-percha E. Polycarboxylate cement

Description : The obturating material of choice for primary teeth following complete pulpectomy is, A. Zn phosphate cement and formcresol combination paste B. Quick setting hydroxide cement C. Zinc oxide and eugenol cement D. Gutta-percha E. Polycarboxylate cement

Last Answer : C. Zinc oxide and eugenol cement

Gypsum is added for (A) Colour (B) Strength (C) Controlling setting time (D) None of these

Description : Gypsum is added for (A) Colour (B) Strength (C) Controlling setting time (D) None of these

Last Answer : Answer: Option C

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

Ordinary Portland cement is manufactured from (A) Lime stone and clay (B) Gypsum and lime (C) Pozzolana (D) Lime, pozzolana and clay

Description : Ordinary Portland cement is manufactured from (A) Lime stone and clay (B) Gypsum and lime (C) Pozzolana (D) Lime, pozzolana and clay

Last Answer : Answer: Option B

Which one of the following is an air binding material? (A) Gypsum (B) Acid-resistant cement (C) Quick lime (D) All of these

Description : Which one of the following is an air binding material? (A) Gypsum (B) Acid-resistant cement (C) Quick lime (D) All of these

Last Answer : Answer: Option D

Rapid hardening cement attains early strength due to (A) Larger proportion of lime grounded finer than normal cement (B) Lesser proportion of lime grounded coarser than normal cement (C) Lesser proportion of lime grounded finer than normal cement (D) Excess percentage of gypsum

Description : Rapid hardening cement attains early strength due to (A) Larger proportion of lime grounded finer than normal cement (B) Lesser proportion of lime grounded coarser than normal cement (C) Lesser proportion of lime grounded finer than normal cement (D) Excess percentage of gypsum

Last Answer : Answer: Option A

The chemical name of Bleaching powder is (A)Calcium Chloride (B) Calcium Chloro-Oxide (C) Calcium Oxychloride (D) Hypochloride

Description : The chemical name of Bleaching powder is (A)Calcium Chloride (B) Calcium Chloro-Oxide (C) Calcium Oxychloride (D) Hypochloride

Last Answer : (C) Calcium Oxychloride

The chemical name of "Plaster of Paris" commonly used for setting broken bones is – (1) Calcium nitrate (2) Calcium sulphate (3) Calcium carbonate (4) Calcium chloride

Description : The chemical name of "Plaster of Paris" commonly used for setting broken bones is – (1) Calcium nitrate (2) Calcium sulphate (3) Calcium carbonate (4) Calcium chloride

Last Answer : (2) Calcium sulphate Explanation: Plaster of Paris is the common name of Calcium Sulphate hemihydrate, with chemical formula: CaSO4.1/2H2O. Plaster of Paris is produced by heating gypsum to about 150°C.