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

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
by

1 Answer

Answer :

Answer: Option C
by

Related questions

Hardness of water is caused by (A) Presence of soap lather (B) Presence of chlorides and sulphates of sodium and potassium (C) Presence of bicarbonates, sulphates or chlorides of calcium and magnesium (D) Turbidity

Description : Hardness of water is caused by  (A) Presence of soap lather  (B) Presence of chlorides and sulphates of sodium and potassium  (C) Presence of bicarbonates, sulphates or chlorides of calcium and magnesium  (D) Turbidity 

Last Answer : (C) Presence of bicarbonates, sulphates or chlorides of calcium and magnesium 

Permanent hardness of water is due to the presence of calcium & magnesium (A) Bi-carbonates (B) Sulphates & chlorides (C) Carbonate (D) None of these

Description : Permanent hardness of water is due to the presence of calcium & magnesium (A) Bi-carbonates (B) Sulphates & chlorides (C) Carbonate (D) None of these

Last Answer : (B) Sulphates & chlorides

Magnesium and calcium __________ cause temporary hardness of water. (A) Carbonates (B) Bicarbonates (C) Phosphates (D) Sulphates

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Last Answer : (B) Bicarbonates

Consider the following statements: 1. Carbonate hardness is due to bicarbonates. 2. Non-carbonate hardness is due to sulphates and chlorides of Ca and Mg. 3. Both the hardnesses can be removed by lime-soda method. 4. Both the hardnesses can be removed by ion-exchange method. Which of these statements are correct? (a) 1, 2 & 3 only (b) 1, 2 & 4 only (c) 2, 3 & 4 only (d) 1, 2, 3 & 4

Description : Consider the following statements: 1. Carbonate hardness is due to bicarbonates. 2. Non-carbonate hardness is due to sulphates and chlorides of Ca and Mg. 3. Both the hardnesses can be removed by lime-soda method. 4. Both the hardnesses can be ... (b) 1, 2 & 4 only (c) 2, 3 & 4 only (d) 1, 2, 3 & 4

Last Answer : (a) 1, 2 & 3 only

Hardness of water can be removed by boiling if it is due to (A) Calcium bicarbonates (B) Calcium sulphates (C) Calcium chloride (D) Calcium nitrates

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Last Answer : (A) Calcium bicarbonates 

Lime and soda ash are added to water to remove (A) Bicarbonates & sulphates of calcium and magnesium (B) Undesirable taste and odour (C) Bacteria (D) Its corrosiveness

Description : Lime and soda ash are added to water to remove (A) Bicarbonates & sulphates of calcium and magnesium (B) Undesirable taste and odour (C) Bacteria (D) Its corrosiveness

Last Answer : (A) Bicarbonates & sulphates of calcium and magnesium

The maximum amount of chlorides and sulphates should not be more than [ A ] 0.15% and 4% by mass of cement respectively [ B ] 4% and 0.15% by mass of cement respectively [ C ] 0.30% and 2% by mass of cement respectively [ D ] 2% and 0.30% by mass of cement respectively

Description : The maximum amount of chlorides and sulphates should not be more than [ A ] 0.15% and 4% by mass of cement respectively [ B ] 4% and 0.15% by mass of cement respectively [ C ] 0.30% and 2% by mass of cement respectively [ D ] 2% and 0.30% by mass of cement respectively

Last Answer : [ A ] 0.15% and 4% by mass of cement respectively

The maximum amount of chlorides and sulphates should not be more than [ A ] 0.15% and 4% by mass of cement respectively [ B ] 4% and 0.15% by mass of cement respectively [ C ] 0.30% and 2% by mass of cement respectively [ D ] 2% and 0.30% by mass of cement respectively

Description : The maximum amount of chlorides and sulphates should not be more than [ A ] 0.15% and 4% by mass of cement respectively [ B ] 4% and 0.15% by mass of cement respectively [ C ] 0.30% and 2% by mass of cement respectively [ D ] 2% and 0.30% by mass of cement respectively

Last Answer : [ A ] 0.15% and 4% by mass of cement respectively

Alkalinity in water may be caused due to (A) Calcium and magnesium bicarbonates (B) Sodium carbonate (C) Potassium carbonate (D) All the above

Description : Alkalinity in water may be caused due to (A) Calcium and magnesium bicarbonates (B) Sodium carbonate (C) Potassium carbonate (D) All the above

Last Answer : (D) All the above

The majority of carbon dioxide produced by our body cells is transported to the lungs as (a) attached to haemoglobin (b) dissolved in the blood (c) as bicarbonates (d) as carbonates.

Description : The majority of carbon dioxide produced by our body cells is transported to the lungs as (a) attached to haemoglobin (b) dissolved in the blood (c) as bicarbonates (d) as carbonates.

Last Answer : (c) as bicarbonates

Explain the stability of carbonates & bicarbonates of alkali metals .

Description : Explain the stability of carbonates & bicarbonates of alkali metals . 

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Last Answer : (C) Silicates & phosphates

__________ are used as corrosion inhibitor for iron & steel in aqueous solutions. (A) Phosphates (B) Chromates (C) Sulphates (D) Bi-carbonates

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Last Answer : (B) Chromates

The commonest form of iron & manganese found in ground water as pollutant is in the form of their (A) Carbonates (B) Bi-carbonates (C) Chlorides (D) Sulphides

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Last Answer : (B) Bi-carbonates

A child consumes a toxic dose of fluoride. You will:** A. Induce vomiting B. Give a lot of fluids C. Give a lot of fluids and sodium bicarbonates D. Ask patient not to eat for 45 minutes E. Give milk, calcium tablets or magnesium tablets

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Last Answer : E. Give milk, calcium tablets or magnesium tablets

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

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Last Answer : (B) Silicates

Hard water contains (A) Calcium (B) Magnesium bicarbonates (C) Magnesium sulphate (D) All the above

Description : Hard water contains  (A) Calcium  (B) Magnesium bicarbonates  (C) Magnesium sulphate  (D) All the above 

Last Answer : (D) All the above 

__________ chloride present in crude petroleum as impurity is the most prolific producer of HCl during distillation. (A) Magnesium (B) Potassium (C) Calcium (D) Sodium

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Last Answer : (A) Magnesium

Addition of pozzolana to ordinary port land cement, causes (A) Decrease in early strength (B) Reduction in chemical action with sulphates (C) Increase in shrinkage (D) All the above

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According to IS:456-2000, the total acid soluble chlorides in concrete is restricted to________ of concrete [ A ] 0.2 kg/m3 [ B ] 0.4 kg/m3 [ C ] 2 kg/m3 [ D ] 4 kg/m3

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Last Answer : [ B ] 0.4 kg/m3

According to IS:456-2000, the total acid soluble chlorides in concrete is restricted to________ of concrete [ A ] 0.2 kg/m3 [ B ] 0.4 kg/m3 [ C ] 2 kg/m3 [ D ] 4 kg/m3

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Last Answer : [ B ] 0.4 kg/m3

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)

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

The process of addition of impurity in pure semiconductor is : a) Doping b) Radiating c) Mixing d) Insulating

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Last Answer : d) Insulating

All the following statements about cystic fibrosis are correct except (A) It is inherited as an autosomal recessive disease (B) It affects a number of exocrine glands (C) It causes increased sweating (D) Sweat chlorides are above 60 mEq/L in this disease

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Last Answer : Answer : C

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Last Answer : (d) All of the above

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

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Last Answer : (A) Gypsum

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

Last Answer : Answer: Option A

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Last Answer : [ A ] i

Diamond is chemically (a) a mixture of metal carbonates (b) pure carbon (c) a pure form of sand (d) a mixture of calcium and magnesium phosphates

Description : Diamond is chemically (a) a mixture of metal carbonates (b) pure carbon (c) a pure form of sand (d) a mixture of calcium and magnesium phosphates

Last Answer : Ans:(b)

Water used for mixing concrete should be [ A ] Slightly acidic [ B ] Free from bacteria [ C ] Distilled [ D ] Potable

Description : Water used for mixing concrete should be [ A ] Slightly acidic [ B ] Free from bacteria [ C ] Distilled [ D ] Potable

Last Answer : [ D ] Potable

Water used for mixing of concrete should be free from (i)Oils (ii)Salts (iii)Acids [ A ] i [ B ] iii [ C ] i and iii [ D ] i, ii and iii

Description : Water used for mixing of concrete should be free from (i)Oils (ii)Salts (iii)Acids [ A ] i [ B ] iii [ C ] i and iii [ D ] i, ii and iii

Last Answer : [ D ] i, ii and iii

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

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Last Answer : b) Calcium chloride*

State as to why: (a) A solution of Na2CO3 is alkaline? (b)alkali metals are prepared by electrolysis of their fused chlorides ? (c)sodium is found to be more useful than potassium ?

Description : State as to why: (a) A solution of Na2CO3 is alkaline? (b)alkali metals are prepared by electrolysis of their fused chlorides ? (c)sodium is found to be more useful than potassium ?

Last Answer : Ans. (a) It undergoes hydrolysis to produce a strong base NaOH . (b) When the aq. Solution of any alkali metal is subjected to electrolysis ,H2 instead of the alkali metal is produced at the ... of sugars and amino acids into the cells. Thus, sodium is found to be more useful than potassium.

The product obtained on mixing calcium oxide with water is called (A) Quicklime (B) Slaked lime (C) Milk of lime (D) None of these

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Pick up the correct statement from the following: (A) Rusting is caused due to combined action of air, moisture and carbon dioxide (B) During rusting, first ferrous bicarbonates are formed (C) On further oxidation ferrous bicarbonates get converted to ferric bicarbonates (D) All the above

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Last Answer : Answer: Option D

In case of hand mixing of concrete, the extra cement to be added is (A) 5 % (B) 10 % (C) 15 % (D) 20 %

Description : In case of hand mixing of concrete, the extra cement to be added is (A) 5 % (B) 10 % (C) 15 % (D) 20 %

Last Answer : (B) 10 %

The process of proper and accurate measurement of concrete ingredients for uniformity of proportion, is known (A) Grading (B) Curing (C) Mixing (D) Batching

Description : The process of proper and accurate measurement of concrete ingredients for uniformity of proportion, is known (A) Grading (B) Curing (C) Mixing (D) Batching

Last Answer : (D) Batching

The produce impermeable concrete (A) Thorough mixing of concrete is required (B) Proper compaction of concrete is required (C) Proper curing of concrete is required (D) All the above

Description : The produce impermeable concrete (A) Thorough mixing of concrete is required (B) Proper compaction of concrete is required (C) Proper curing of concrete is required (D) All the above

Last Answer : Answer: Option D

The process of mixing, transporting, placing and compacting concrete using Ordinary Port land Cement should not take more than (A) 30 minutes (B) 40 minutes (C) 60 minutes (D) 90 minutes

Description : The process of mixing, transporting, placing and compacting concrete using Ordinary Port land Cement should not take more than (A) 30 minutes (B) 40 minutes (C) 60 minutes (D) 90 minutes

Last Answer : Answer: Option A

The process of mixing, transporting, placing and compacting the cement, concrete should not take more than. (a) 30 minutes (b) 60minutes (c) 90 minutes (d) 120mm

Description : The process of mixing, transporting, placing and compacting the cement, concrete should not take more than. (a) 30 minutes (b) 60minutes (c) 90 minutes (d) 120mm

Last Answer : (a) 30 minutes

The process of proper and accurate measurement of concrete ingredients for uniformity of proportion, is known as [ A ] Curing [ B ] Mixing [ C ] Grading [ D ] Batching

Description : The process of proper and accurate measurement of concrete ingredients for uniformity of proportion, is known as [ A ] Curing [ B ] Mixing [ C ] Grading [ D ] Batching

Last Answer : [ D ] Batching

For testing compressive and tensile strength of cement, the cement mortar is made by mixing cement and standard sand in the proportions of (A) 1 : 2 (B) 1 : 3 (C) 1 : 4 (D) 1 : 6

Description : For testing compressive and tensile strength of cement, the cement mortar is made by mixing cement and standard sand in the proportions of (A) 1 : 2 (B) 1 : 3 (C) 1 : 4 (D) 1 : 6

Last Answer : Answer: Option B

Carbonates in water produce (A) Temporary hardness (B) Permanent hardness (C) Acidity (D) Alkanity

Description : Carbonates in water produce (A) Temporary hardness (B) Permanent hardness (C) Acidity (D) Alkanity

Last Answer : (A) Temporary hardness

Finer grinding of cement (A) Affects only the early development of strength (B) Affects only the ultimate strength (C) Both (A) and (B) (D) Does not affect the strength

Description : Finer grinding of cement (A) Affects only the early development of strength (B) Affects only the ultimate strength (C) Both (A) and (B) (D) Does not affect the strength

Last Answer : Answer: Option A

The basic purpose of a retarder in concrete is (A) To increase the initial setting time of cement paste in concrete (B) To decrease the initial setting time of cement paste in concrete (C) To render the concrete more water tight (D) To improve the workability of concrete mix

Description : The basic purpose of a retarder in concrete is (A) To increase the initial setting time of cement paste in concrete (B) To decrease the initial setting time of cement paste in concrete (C) To render the concrete more water tight (D) To improve the workability of concrete mix

Last Answer : Answer: Option A

Mathamoglobinemia or blue baby disease is caused due to (A) Chlorides (B) Nitrites (C) Nitrates (D) Sulphides

Description : Mathamoglobinemia or blue baby disease is caused due to  (A) Chlorides  (B) Nitrites  (C) Nitrates  (D) Sulphides 

Last Answer : (C) Nitrates 

Which one of the following tests employs Ethylene Diamine Tetra Acetic Acid as a titrating agent? (a) Chlorides (b) Dissolved oxygen (c) Hardness (d) Residual chlorine

Description : Which one of the following tests employs Ethylene Diamine Tetra Acetic Acid as a titrating agent? (a) Chlorides (b) Dissolved oxygen (c) Hardness (d) Residual chlorine

Last Answer : (c) Hardness

Teeth and Bones acquire strength and rigidity from (1) Calcium (2) Fluorine (3) Chlorine (4) Sodium

Description : Teeth and Bones acquire strength and rigidity from (1) Calcium (2) Fluorine (3) Chlorine (4) Sodium

Last Answer : Calcium

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

Fly ash when added to concrete [ A ] Acts as aggregates [ B ] Acts as pozzolona [ C ] Improves appearance [ D ] Reduces setting time

Description : Fly ash when added to concrete [ A ] Acts as aggregates [ B ] Acts as pozzolona [ C ] Improves appearance [ D ] Reduces setting time

Last Answer : [ B ] Acts as pozzolona