The reduction of the PH value, by the action of atmospheric carbon dioxide with the alkali of the cement paste is called [ A ] atmospheric corrosion [ B ] chloride corrosion [ C ] oxidation [ D ] carbonation

The reduction of the PH value, by the action of atmospheric carbon dioxide with the alkali of the cement paste is called
[ A ] atmospheric corrosion
[ B ] chloride corrosion
[ C ] oxidation
[ D ] carbonation
by

1 Answer

Answer :

[ D ] carbonation
by

Related questions

The reduction of the PH value, by the action of atmospheric carbon dioxide with the alkali of the cement paste is called [ A ] atmospheric corrosion [ B ] chloride corrosion [ C ] oxidation [ D ] carbonation

Description : The reduction of the PH value, by the action of atmospheric carbon dioxide with the alkali of the cement paste is called [ A ] atmospheric corrosion [ B ] chloride corrosion [ C ] oxidation [ D ] carbonation

Last Answer : [ D ] carbonation

Rusting of iron takes place due to – (1) oxidation (2) carbonation (3) exfoliation (4) corrosion

Description : Rusting of iron takes place due to – (1) oxidation (2) carbonation (3) exfoliation (4) corrosion

Last Answer : (1) oxidation Explanation: The rusting of iron is an electrochemical process that begins with the transfer of electrons from iron to oxygen. The rate of corrosion is affected by water and accelerated by ... iron is in contact with water, oxygen, or other strong oxidants, or acids, it rusts.

Rusting of iron takes place due to (1) oxidation (2) carbonation (3) exfoliation (4) corrosion

Description : Rusting of iron takes place due to (1) oxidation (2) carbonation (3) exfoliation (4) corrosion 

Last Answer : oxidation

Chemical weathering of soil is caused due to (A) Oxidation (B) Carbonation (C) Hydration (D) All the above

Description : Chemical weathering of soil is caused due to (A) Oxidation (B) Carbonation (C) Hydration (D) All the above

Last Answer : Answer: Option D

Corrosion in boilers can be prevented by (A) Deaeration of feed water (B) Enhancing pH of feed water by adding alkali (C) Feeding sodium sulphite or hydrazine phosphate to the boilers, which combines with oxygen and prevents corrosion (D) All (A), (B) and (C)

Description : Corrosion in boilers can be prevented by (A) Deaeration of feed water (B) Enhancing pH of feed water by adding alkali (C) Feeding sodium sulphite or hydrazine phosphate to the boilers, which combines with oxygen and prevents corrosion (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

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

Description : 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

Last Answer : Answer: Option D

If the body undergoes alkalosis the respiratory center located in the medulla gets the information and induces the lowering of the respiratory frequency. The reduction of the respiratory frequency makes the body retain more carbon dioxide and to shift the equilibrium of the formation of bicarbonate towards the production of more hydrogen ions and thus the blood pH lowers.

Description : If the body undergoes alkalosis the respiratory center located in the medulla gets the information and induces the lowering of the respiratory frequency. The reduction of the respiratory frequency makes ... of bicarbonate towards the production of more hydrogen ions and thus the blood pH lowers.

Last Answer : What is the difference between respiratory acidosis and metabolic acidosis and what is the difference between respiratory alkalosis and metabolic alkalosis?

When water itself combines chemically with some element or mineral it is called – (1) Carbonation (2) Desilication (3) Hydration (4) Oxidation

Description : When water itself combines chemically with some element or mineral it is called – (1) Carbonation (2) Desilication (3) Hydration (4) Oxidation

Last Answer : (3) Hydration Explanation: When water combines chemically with other elements, the process is called hydration. In organic chemistry, a hydration reaction is a chemical reaction in which a hydroxyl ... runs in a strong acidic, aqueous solution. Hydration leaves the non-water component intact.

When water itself combines chemically with some element or mineral it is called (1) Carbonation (2) Desilication (3) Hydration (4) Oxidation

Description : When water itself combines chemically with some element or mineral it is called (1) Carbonation (2) Desilication (3) Hydration (4) Oxidation

Last Answer : Hydration

One of the steps during refining of cane sugar consists of addition ofhydrated lime to the sugar syrup followed by carbonation of the resultingsolution. The purpose of this step is to(A) Adjust the pH of the syrup(B) Remove the coloring matter from the syrup(C) Reduce the viscosity of the syrup(D) Improve the rate of crystallisation of sugar

Description : One of the steps during refining of cane sugar consists of addition ofhydrated lime to the sugar syrup followed by carbonation of the resulting solution. The purpose of this step is to (A) Adjust ... (C) Reduce the viscosity of the syrup (D) Improve the rate of crystallisation of sugar

Last Answer : (A) Adjust the pH of the syrup

Atmospheric corrosion of metals result from their (A) Slow oxidation (B) Fast oxidation (C) Fast hydration (D) Slow dehydration

Description : Atmospheric corrosion of metals result from their (A) Slow oxidation (B) Fast oxidation (C) Fast hydration (D) Slow dehydration

Last Answer : (A) Slow oxidation

. Plasticisers are added to paints to (A) Make it corrosion resistant (B) Make glossy surface (C) Give elasticity & prevent cracking of the film (D) Increase atmospheric oxidation

Description : . Plasticisers are added to paints to (A) Make it corrosion resistant (B) Make glossy surface (C) Give elasticity & prevent cracking of the film (D) Increase atmospheric oxidation

Last Answer : (C) Give elasticity & prevent cracking of the film

Moist atmospheric air at high temperature (e.g., in summer) having high concentration of sulphur dioxide causes(A) Fading of dyes on textiles(B) Corrosion, tarnishing & soiling of metals(C) Reduced strength of textiles(D) All (A), (B) and (C)

Description : Moist atmospheric air at high temperature (e.g., in summer) having high concentration of sulphur dioxide causes (A) Fading of dyes on textiles (B) Corrosion, tarnishing & soiling of metals (C) Reduced strength of textiles (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

Higher concentration of nitrogen dioxide in atmospheric air causes (A) Cancer (B) Bronchitis (C) Asphyxiation (D) Corrosion

Description : Higher concentration of nitrogen dioxide in atmospheric air causes (A) Cancer (B) Bronchitis (C) Asphyxiation (D) Corrosion

Last Answer : (B) Bronchitis

Sulphur dioxide present in the industrial chimney exhaust gases causes (A) Respiratory & lung disease (B) Reduction in plant's productivity owing to acid rain (C) Corrosion of building materials (D) All (A), (B) and (C)

Description : Sulphur dioxide present in the industrial chimney exhaust gases causes (A) Respiratory & lung disease (B) Reduction in plant's productivity owing to acid rain (C) Corrosion of building materials (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

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

Description : 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

Last Answer : Answer: Option D

Pick up the incorrect statement from the following: (A) The degree of grinding of cement, is called fineness (B) The process of changing cement paste into hard mass, is known as setting of cement (C) The phenomenon by virtue of which cement does not allow transmission of sound, is known as soundness of cement (D) The heat generated during chemical reaction of cement with water, is known as heat of hydration

Description : Pick up the incorrect statement from the following: (A) The degree of grinding of cement, is called fineness (B) The process of changing cement paste into hard mass, is known as setting of ... (D) The heat generated during chemical reaction of cement with water, is known as heat of hydration

Last Answer : Answer: Option C

When each particle of aggregates is thinly coated with cement paste, a heterogeneous solid is formed, which is known as (A) Hydration (B) Gel (C) Concrete (D) None of these

Description : When each particle of aggregates is thinly coated with cement paste, a heterogeneous solid is formed, which is known as (A) Hydration (B) Gel (C) Concrete (D) None of these

Last Answer : Answer: Option C

If 1500 g of water is required to have a cement paste 1875 g of normal consistency, the percentage of water is, (A) 20 % (B) 25 % (C) 30 % (D) 35 %

Description : If 1500 g of water is required to have a cement paste 1875 g of normal consistency, the percentage of water is, (A) 20 % (B) 25 % (C) 30 % (D) 35 %

Last Answer : (B) 25 %

In the method of voids for determination of the quantity of cement paste, it is assumed that (A) Voids in coarse aggregates are filled by fine aggregates (B) Voids in fine aggregates are filled by the cement paste (C) Volume of fine aggregates is equal to total voids in coarse aggregates plus 10% extra (D) All the above

Description : In the method of voids for determination of the quantity of cement paste, it is assumed that (A) Voids in coarse aggregates are filled by fine aggregates (B) Voids in fine aggregates are filled by ... of fine aggregates is equal to total voids in coarse aggregates plus 10% extra (D) All the above

Last Answer : Answer: Option D

Pick up the correct statement from the following: (A) Water cement paste hardens due to hydration (B) During hardening cement binds the aggregates together (C) Cement provides strength, durability and water tightness to the concrete (D) All the above

Description : Pick up the correct statement from the following: (A) Water cement paste hardens due to hydration (B) During hardening cement binds the aggregates together (C) Cement provides strength, durability and water tightness to the concrete (D) All the above

Last Answer : Answer: Option D

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

The percentage of water for making a cement paste of normal consistency varies from (a) 15 to 25% (b) 25 to 35% (c) 35 to 50% (d) 50 to 60%

Description : The percentage of water for making a cement paste of normal consistency varies from (a) 15 to 25% (b) 25 to 35% (c) 35 to 50% (d) 50 to 60%

Last Answer : (b) 25 to 35%

Cement setting under water employs a/an __________ process. (A) Hydration (B) Decomposition (C) Oxidation (D) Reduction

Description : Cement setting under water employs a/an __________ process. (A) Hydration (B) Decomposition (C) Oxidation (D) Reduction

Last Answer : (A) Hydration

A coal gasifier operating at 20 atm. (e.g. Lurgi gasifier) as compared to one operating at atmospheric pressure (e.g. Kopper-Totzek or Winkler gasifier) will produce a gas having (A) Higher methane content and thus higher calorific value (B) Higher carbon monoxide content(C) Lower carbon dioxide content(D) None of these

Description : A coal gasifier operating at 20 atm. (e.g. Lurgi gasifier) as compared to one operating at atmospheric pressure (e.g. Kopper-Totzek or Winkler gasifier) will produce a gas having (A) Higher ... calorific value (B) Higher carbon monoxide content (C) Lower carbon dioxide content (D) None of these

Last Answer : (A) Higher methane content and thus higher calorific value

Sulphur dioxide bleaches colouring matter by – (1) Reduction (2) Dehydration (3) Decomposition (4) Oxidation

Description : Sulphur dioxide bleaches colouring matter by – (1) Reduction (2) Dehydration (3) Decomposition (4) Oxidation

Last Answer : (1) Reduction Explanation: Sulphur dioxide gas exhibits bleaching properties in presence of moisture. It dissolves in water liberating nascent hydrogen. Nascent hydrogen removes oxygen atoms from the colouring matter (reduces colouring matter) and it loses its colour.

Sulphur dioxide bleaches colouring matter by : (1) Reduction (2) Dehydration (3) Decomposition (4) Oxidation

Description : Sulphur dioxide bleaches colouring matter by : (1) Reduction (2) Dehydration (3) Decomposition (4) Oxidation

Last Answer : Reduction

How can wet carbon dioxide be responsible for a corrosion problem in iron-containing metals? How can wet carbon dioxide be responsible for a corrosion problem in iron-containing metals?

Description : How can wet carbon dioxide be responsible for a corrosion problem in iron-containing metals?

Last Answer : Carbon dioxide reacts with water according to the following equation: CO2 + H2O -> HCO3- + H+ As the concentration of CO2 increases, so does the concentration of the H+ ion. This ion ... ions produced can react with the bicarbonate ions to form ferrous carbonate, which precipitates as a scale.

A solution which resists change in its pH value on addition of acid/alkali is called the __________ solution. (A) Neutral (B) Ideal (C) Buffer (D) Zero pH

Description : A solution which resists change in its pH value on addition of acid/alkali is called the __________ solution. (A) Neutral (B) Ideal (C) Buffer (D) Zero pH

Last Answer : Option C

Pick up the correct statement from the following: (A) Sand obtained from pits, is washed to remove clay and silt (B) Sand obtained from flooded pits, need not be washed before use (C) The chloride in sea shore sand and shingle may cause corrosion of reinforcement if the concrete is porous (D) All the above

Description : Pick up the correct statement from the following: (A) Sand obtained from pits, is washed to remove clay and silt (B) Sand obtained from flooded pits, need not be washed before use (C) The ... shore sand and shingle may cause corrosion of reinforcement if the concrete is porous (D) All the above

Last Answer : Answer: Option D

Pick up the correct statement from the following: (A) A soil having pH value more than 7 is an acidic soil (B) A soil having pH value less than 7 is an acidic soil (C) A soil having pH value more than 7 is an alkaline soil (D) A soil containing chemicals for the manufacture of Portland cement is preferred

Description : Pick up the correct statement from the following: (A) A soil having pH value more than 7 is an acidic soil (B) A soil having pH value less than 7 is an acidic soil (C) A soil ... more than 7 is an alkaline soil (D) A soil containing chemicals for the manufacture of Portland cement is preferred

Last Answer : Answer: Option B

What is the pH value of alkali ?

Last Answer : pg value of alkali is above 7

Buffer solutions have constant acidity and alkalinity because: (1) they have fixed value of pH (2) these give unionised acid or base on reaction with added acid or alkali (3) acids and alkalies in these solutions are shielded from attack by other ions (4) they have large excess of H+ or OH– ions

Description : Buffer solutions have constant acidity and alkalinity because: (1) they have fixed value of pH (2) these give unionised acid or base on reaction with added acid or alkali (3) acids and alkalies in these solutions are shielded from attack by other ions (4) they have large excess of H+ or OH– ions

Last Answer : these give unionised acid or base on reaction with added acid or alkali

Asserarion:Bleaching action action of `SO_(2)` is temporary and by reduction. Reason: The colour of material is regained due to oxidation by air.

Description : Asserarion:Bleaching action action of `SO_(2)` is temporary and by reduction. Reason: The colour of material is regained due to oxidation by air.

Last Answer : Asserarion:Bleaching action action of `SO_(2)` is temporary and by reduction. Reason: The colour of material is regained due to oxidation by air.

Asserarion:Bleaching action action of `SO_(2)` is temporary and by reduction. Reason: The colour of material is regained due to oxidation by air.

Description : Asserarion:Bleaching action action of `SO_(2)` is temporary and by reduction. Reason: The colour of material is regained due to oxidation by air.

Last Answer : Asserarion:Bleaching action action of `SO_(2)` is temporary and by reduction. Reason: The colour of ... -I is not correct and Statement-II is correct

Bleaching action of chlorine is by - (1) Decomposition (2) hydrolysis (3) reduction (4) oxidation

Description : Bleaching action of chlorine is by - (1) Decomposition (2) hydrolysis (3) reduction (4) oxidation

Last Answer : (4) oxidation Explanation: Chlorine bleaches by the process of oxidation. It needs moisture for its bleaching action. Chlorine reacts with water to form hydrochloric and hypochlorous acids.

Bleaching action of chlorine is by - (1) decomposition (2) hydrolysis (3) reduction (4) oxidation

Description : Bleaching action of chlorine is by - (1) decomposition (2) hydrolysis (3) reduction (4) oxidation

Last Answer : (4) oxidation Explanation: Chlorine bleaches by the process of oxidation. It needs moisture for its bleaching action. Chlorine reacts with water to form hydrochloric and hypochlorous acids.

Bleaching action of chlorine is by----? A. Oxidation (Answer) B. Reduction C. Decomposition D. Hydrolysis

Description : Bleaching action of chlorine is by----? A. Oxidation (Answer) B. Reduction C. Decomposition D. Hydrolysis

Last Answer : A. Oxidation (Answer)

The action of concentrated sulfuric acid on sugar best described as: w) catalysis x) oxidation y) reduction z) dehydration

Description : The action of concentrated sulfuric acid on sugar best described as: w) catalysis x) oxidation y) reduction z) dehydration

Last Answer : ANSWER: Z -- DEHYDRATION

A thick paste of cement, sand and water is called – (1) Concrete (2) R.C.C. (3) Mortar (4) Kiln

Description : A thick paste of cement, sand and water is called – (1) Concrete (2) R.C.C. (3) Mortar (4) Kiln

Last Answer : (3) Mortar Explanation: Mortar is a workable paste used to bind construction blocks together and fill the gaps between them. Modern mortars are typically made from a mixture of sand, a binder such as cement or lime, and water

A thick paste of cement, sand and water is called (1) Concrete (2) R.C.C. (3) Mortar (4) Kiln

Description : A thick paste of cement, sand and water is called (1) Concrete (2) R.C.C. (3) Mortar (4) Kiln

Last Answer : Mortar

Partial pressure of carbon dioxide in Alveoli , atmospheric air and tissures will be `:-`

Description : Partial pressure of carbon dioxide in Alveoli , atmospheric air and tissures will be `:-`

Last Answer : Partial pressure of carbon dioxide in Alveoli , atmospheric air and tissures will be `:-` A. 0.3,40,45 B. 40,0.3,45 C. 0.3,104,28 D. 104,159,40

What is The atmospheric concentration of carbon dioxide is regulated by?

Description : What is The atmospheric concentration of carbon dioxide is regulated by?

Last Answer : Need answer

'Green House Effect' means – (1) Pollution in houses in tropical regions (2) Trapping of solar energy due to atmospheric oxygen (3) Trapping of solar energy due to atmospheric carbon dioxide (4) Cultivation in green houses so as to check pollution

Description : 'Green House Effect' means – (1) Pollution in houses in tropical regions (2) Trapping of solar energy due to atmospheric oxygen (3) Trapping of solar energy due to atmospheric carbon dioxide (4) Cultivation in green houses so as to check pollution

Last Answer : (3) Trapping of solar energy due to atmospheric carbon dioxide Explanation: The greenhouse effect is a process by which thermal radiation from a planetary surface is absorbed by atmospheric ... fuels and clearing of forests, have intensified the natural greenhouse effect, causing global warming.

'Green House Effect' means - (1) cultivation of crops in green house to conserve heat (2) trapping of solar energy due to carbon dioxide gases (3) trapping of solar energy by earth upper surface (4) increase of heat due to atmospheric pollution

Description : 'Green House Effect' means - (1) cultivation of crops in green house to conserve heat (2) trapping of solar energy due to carbon dioxide gases (3) trapping of solar energy by earth upper surface (4) increase of heat due to atmospheric pollution

Last Answer : (2) trapping of solar energy due to carbon dioxide gases Explanation: Green House Effect is a process by which thermal radiation from a planetary surface is absorbed by atmospheric greenhouse gases and is re-radiated in all directions.

The 'Greenhouse effect' is mainly due to increase in atmospheric – (1) Ozone (2) Nitrogen (3) Sulphur dioxide (4) Carbon dioxide

Description : The 'Greenhouse effect' is mainly due to increase in atmospheric – (1) Ozone (2) Nitrogen (3) Sulphur dioxide (4) Carbon dioxide

Last Answer : (4) Carbon dioxide Explanation: Carbon dioxide is the primary greenhouse gas that is contributing to recent climate change, 72% of the totally emitted greenhouse gases is carbon dioxide (CO2), 18% Methane ... (NOx). Carbon dioxide emissions therefore are the most important ca s e of global warming.

Which is a significant contributor to increased levels of atmospheric carbon dioxide?

Description : Which is a significant contributor to increased levels of atmospheric carbon dioxide?

Last Answer : Deforestation

Oceans act as sinks for atmospheric gases including carbon dioxide whose concentration in the atmosphere is increased by the (A) Forestation (B) Rain (C) Green house effect (D) Vegetation

Description : Oceans act as sinks for atmospheric gases including carbon dioxide whose concentration in the atmosphere is increased by the (A) Forestation (B) Rain (C) Green house effect (D) Vegetation

Last Answer : (C) Green house effect

“Azotobacter” bacteria is known for biological fixation of which atmospheric gas? a. A Oxygen b. B Nitrogen c. C Carbon Dioxide d. D Helium

Description : “Azotobacter” bacteria is known for biological fixation of which atmospheric gas? a. A Oxygen b. B Nitrogen c. C Carbon Dioxide d. D Helium

Last Answer : b. B Nitrogen

“Azotobacter” bacteria is known for biological fixation of which atmospheric gas? a. A Oxygen b. B Nitrogen c. C Carbon Dioxide d. D Helium

Description : “Azotobacter” bacteria is known for biological fixation of which atmospheric gas? a. A Oxygen b. B Nitrogen c. C Carbon Dioxide d. D Helium

Last Answer : b. B Nitrogen