(4) Decomposition of manganese dioxide Explanation: One of the two chemical methods starts from natural manganese dioxide and converts it using dinitrogen tetroxide and water to manganese nitrate solution. Evaporation of the water leaves the crystalline nitrate salt. At temperatures of 400°C, the salt decomposes, releasing N2O4 and leaving a residue of purified manganese dioxide.

(4) Decomposition of manganese dioxide Explanation: One of the two chemical methods starts from natural manganese dioxide and converts it using dinitrogen tetroxide and water to manganese nitrate solution. Evaporation of the water leaves the crystalline nitrate salt. At temperatures of 400°C, the salt decomposes, releasing N2O4 and leaving a residue of purified manganese dioxide.
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The mass number of a nucleus is - (1) always less than its atomic number (2) the sum of the number of protons and neutrons present in the nucleus (3) always more than the atomic weight (4) a fraction
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Description : Which two distinct microbial processes are responsible for the release of fixed nitrogen as dinitrogen gas (N2) to the atmosphere? (a) Aerobic nitrate oxidation and nitrite reduction (b) ... fixation by Rhizobium in root nodules of legumes (d) Anaerobic ammonium oxidation and denitrification

Last Answer : (d) Anaerobic ammonium oxidation and denitrification

Calcium carbonate decomposes into calcium oxide & carbon dioxide Her results:Mass of calcium carbonate before heating = 2.00 g Mass of calcium oxide left after heating = 1.12 g work out the mass of carbon dioxide released during the decomposition?

Description : Calcium carbonate decomposes into calcium oxide & carbon dioxide Her results:Mass of calcium carbonate before heating = 2.00 g Mass of calcium oxide left after heating = 1.12 g work out the mass of carbon dioxide released during the decomposition?

Last Answer : I am not sure of the answer so can someone help me pls

(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

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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

Which of the following is not a method of preparing oxygen? (1) Electrolysis of water (2) Fractional distillation of liquid air (3) Decomposition of potassium permanganate (4) Decomposition of manganese dioxide

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`Ti` can be purified by Van Arkel process. `TiI_(4)` is a volatile compound which decomposes at a high temperature.

Description : `Ti` can be purified by Van Arkel process. `TiI_(4)` is a volatile compound which decomposes at a high temperature.

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A salt gives white residue in charcoal cavity test but in cobalt nitrate test it gives pink mass. It represents :

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Both rubies and sapphires contain (a) silicon dioxide (b) lead tetroxide (c) aluminium oxide (d) boron nitride

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Last Answer : Ans:(c)

Decomposition rate of a liquid 'X' which decomposes as per the reaction as shown in the bellow figure is given by: (A) K1 . CX (B) (K1 + K2 + K3 ) CX (C) (K1 + K2 ) CX (D) (K2 + K3 ) CX

Description : Decomposition rate of a liquid 'X' which decomposes as per the reaction as shown in the bellow figure is given by: (A) K1 . CX (B) (K1 + K2 + K3 ) CX (C) (K1 + K2 ) CX (D) (K2 + K3 ) CX

Last Answer : (C) (K1 + K2 ) CX

One feels cold after a dip in sea water due to (a) convection currents (b) the deposition of salt on the body (c) the evaporation of water on the body (d) the difference in temperatures between land and sea

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Sea water can be purified by the process of – (1) distillation (2) evaporation (3) filtration (4) fractional distillation

Description : Sea water can be purified by the process of – (1) distillation (2) evaporation (3) filtration (4) fractional distillation

Last Answer : (1) distillation Explanation: The traditional process used in desalination operations is vacuum distillation- essentially the boiling of water at less than atmospheric pressure and thus a much ... when the vapor pressure equals the ambient pressure and vapor pressure increases with temperature.

Sea water can be purified by the process of (1) distillation (2) evaporation (3) filtration (4) fractional distillation

Description : Sea water can be purified by the process of (1) distillation (2) evaporation (3) filtration (4) fractional distillation

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Which one of the following statements about PYROLYSIS, which is a process for solid waste treatment is incorrect? (1) It converts the waste into solid, liquid and gas of which the resultant liquid and gas can be used to produce energy. (2) The process occurs at a temperature above 430°C at atmospheric pressure. (3) The process occurs under high pressure at temperature above 430° C. (4) It is a thermo chemical decomposition of organic waste

Description : Which one of the following statements about PYROLYSIS, which is a process for solid waste treatment is incorrect? (1) It converts the waste into solid, liquid and gas of which the resultant liquid ... pressure at temperature above 430° C. (4) It is a thermo chemical decomposition of organic waste

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(2) brown bottles stops the passage of light through it Explanation: Silver Nitrate is stored in dark bottles in a laboratory to prevent chemical reactions as it is sensitive to light. It reacts to light to produce silver metal.

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At temperatures above 96 degrees Celsius, which crystalline form of sulfur is the most stable?

Description : At temperatures above 96 degrees Celsius, which crystalline form of sulfur is the most stable?

Last Answer : ANSWER: MONOCLINIC

mmonium nitrate is (A) Having about 40% N2 (B) Not hygroscopic (C) Not prone to explosive thermal decomposition (D) Mixed with limestone powder to reduce its explosive nature before using it as a fertilizer

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Last Answer : (D) Mixed with limestone powder to reduce its explosive nature before using it as a fertilizer

The chemical name of 'Common salt' is (1) Sodium chloride (2) Sodium nitrate (3) Ammonium chloride (4) Calcium chloride

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Last Answer : (1) Sodium chloride Explanation: Sodium chloride, also known as salt, common salt, table salt or halite, is an ionic compound with the formula NaCl, representing equal proportions of sodium and ... each ion is surrounded by six ions of, the opposite charge as expected on electrostatic grounds.

The chemical name of ‘Common salt’ is (1) Sodium chloride (2) Sodium nitrate (3) Ammonium chloride (4) Calcium chloride

Description : The chemical name of ‘Common salt’ is (1) Sodium chloride (2) Sodium nitrate (3) Ammonium chloride (4) Calcium chloride

Last Answer : Sodium chloride

Pick out the wrong statement. (A) Catalytic converter is fitted in automobiles to reduce carbon monoxide concentration in exhaust emissions (B) Inhalation of pollutant carbon monoxide results in death by asphyxiation (C) Sulphur dioxide is the main pollutant emitted from the exhaust of petrol driven automobiles (D) Decomposition of plants containing chlorophyll is a natural source of carbon monoxide in atmosphere

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Last Answer : (C) Sulphur dioxide is the main pollutant emitted from the exhaust of petrol driven automobiles

In the cell which organelle has the function of using oxygen in the breakdown of glucose releasing energy and carbon dioxide?

Description : In the cell which organelle has the function of using oxygen in the breakdown of glucose releasing energy and carbon dioxide?

Last Answer : The mitochondria.

(4) Liquid Hydrogen + Liquid Oxygen Explanation: LOX and liquid hydrogen, used in the Space Shuttle orbiter, the Centaur upper stage of the Atlas V, Saturn V upper stages, the newer Delta IV rocket, the H-IIA rocket, and most stages of the European Ariane rockets. Liquid fueled rocicets have higher specific impulse than solid rockets and are capable of being throttled, shut down, and restarted. Only the combustion chamber of a liquid fueled rocket needs to withstand high combustion pressures and temperatures and they can be regeneratively cooled by the liquid propellant.

Description : (4) Liquid Hydrogen + Liquid Oxygen Explanation: LOX and liquid hydrogen, used in the Space Shuttle orbiter, the Centaur upper stage of the Atlas V, Saturn V upper stages, the ... to withstand high combustion pressures and temperatures and they can be regeneratively cooled by the liquid propellant.

Last Answer : The BOD values of water indicate the (1) amount of organic debris (2) amount of oxygen used for biochemical oxidation (3) amount of oxygen used for biochemical reduction (4) amount of ozone used for biochemical oxidation

Assertion: Black soils are black in colour due to diffusion of iron in crystalline and metamorphic rocks. Reason: They develop deep cracks during hot weather Options: (a) Both A and R are true and R is the correct explanation of A. (b) Both A and R are true and R is not the correct explanation of A.(c) A is true but B is false. (d) A is false but R is true.

Description : Assertion: Black soils are black in colour due to diffusion of iron in crystalline and metamorphic rocks. Reason: They develop deep cracks during hot weather Options: (a) Both A and R are true and R is the correct explanation of ... of A.(c) A is true but B is false. (d) A is false but R is true.

Last Answer : (d) A is false but R is true.

By what name is dinitrogen oxide commonly known?

Description : By what name is dinitrogen oxide commonly known? 

Last Answer : ANSWER: LAUGHING GAS (ACCEPT NITROUS OR NITROUS OXIDE)  

What is the total number of protons in Tetranitrogen tetroxide?

Description : What is the total number of protons in Tetranitrogen tetroxide?

Last Answer : Four

A white sodium salt dissolves readily in water to give a solution which is neutral to litmus. When silver nitrate solution is added to the aforementio

Description : A white sodium salt dissolves readily in water to give a solution which is neutral to litmus. When silver nitrate solution is added to the aforementio

Last Answer : A white sodium salt dissolves readily in water to give a solution which is neutral to litmus. When silver nitrate solution ... . `S^(2-)` D. `Cl^(-)`

A white sodium salt dissolves readily in water to give a solution which is neutral to litmus. When silver nitrate solution is added to the solution, a

Description : A white sodium salt dissolves readily in water to give a solution which is neutral to litmus. When silver nitrate solution is added to the solution, a

Last Answer : A white sodium salt dissolves readily in water to give a solution which is neutral to litmus. When silver nitrate solution ... (3)^(2-)` D. `S^(2-)`

What is the unit of the rate constant in a chemical reaction in which 10% of the reactant decomposes in one hour, 20% in two hours, 30% in three hours and so on? (A) Litre/mole.second (B) Moles/litre.second (C) Litre/mole (D) Litre/second

Description : What is the unit of the rate constant in a chemical reaction in which 10% of the reactant decomposes in one hour, 20% in two hours, 30% in three hours and so on? (A) Litre/mole.second (B) Moles/litre.second (C) Litre/mole (D) Litre/second

Last Answer : (A) Litre/mole.second

Which one of the following statements about PYROLYSIS, which is a process for solid waste treatment is incorrect? (1) It converts the waste into solid, liquid and gas of which the resultant liquid and gas can be used to produce energy. (2) The process occurs at a temperature above 430°C at atmospheric pressure. (3) The process occurs under high pressure at temperature above 430° C. (4) It is a thermochemical decomposition of organic waste

Description : Which one of the following statements about PYROLYSIS, which is a process for solid waste treatment is incorrect? (1) It converts the waste into solid, liquid and gas of which the resultant ... high pressure at temperature above 430° C. (4) It is a thermochemical decomposition of organic waste

Last Answer : The process occurs at a temperature above 430°C at atmospheric pressure.

(3) Conversion of ammonia to nitrites Explanation: Nitrification is the biological oxidation of ammonia or ammonium to nitrite followed by the oxidation of the nitrite to nitrate. The oxidation of ammonia into nitrite is performed by two groups of organisms, ammonia-oxidizing bacteria AOB) and ammonia-oxidizing archaea (AOA). Nitrification is an important step in the nitrogen cycle in soil.

Description : (3) Conversion of ammonia to nitrites Explanation: Nitrification is the biological oxidation of ammonia or ammonium to nitrite followed by the oxidation of the nitrite to nitrate. The oxidation of ammonia ... -oxidizing archaea (AOA). Nitrification is an important step in the nitrogen cycle in soil.

Last Answer : Acid rain is caused due to pollution of atmosphere by – (1) oxides of carbon and nitrogen (2) oxides of nitrogen and sulphur (3) oxides of nitrogen and phosphorous (4) None of these

(1) aluminium powder and ammonium nitrate Explanation: Ammonal is an explosive made up of ammonium nitrate and aluminium powder. The ammonium nitrate functions as an oxidizer and the aluminium as fuel. The use of the relatively cheap ammonium nitrate and aluminium makes it a replacement for pure TNT. The mixture is affected by humidity because ammonium nitrate is highly hygroscopic. Ammonal is not easily detonated, requiring a fairly substantial shock, though it is still more sensitive than trinitrotoluene and composition C4.

Description : (1) aluminium powder and ammonium nitrate Explanation: Ammonal is an explosive made up of ammonium nitrate and aluminium powder. The ammonium nitrate functions as an oxidizer and the aluminium ... a fairly substantial shock, though it is still more sensitive than trinitrotoluene and composition C4.

Last Answer : Gelatin is mostly used in making icecreams in order to - (1) prevent making a colloid (2) stabilise the colloid and prevent crystallisation (3) stabilise mixture (4) enrich the aroma

Secondary hardening in steels arises out of the (A) Precipitation of fine alloy carbides at high temperatures (B) Refinement of ferrite grain size by working (C) Decomposition of retained austenite upon heat treatment (D) Precipitation of complex inter-metallic upon heat treatment

Description : Secondary hardening in steels arises out of the (A) Precipitation of fine alloy carbides at high temperatures (B) Refinement of ferrite grain size by working (C) Decomposition of retained austenite upon heat treatment (D) Precipitation of complex inter-metallic upon heat treatment

Last Answer : Option C

What are the methods of treatment & disposal of radioactive wastes? (A) Evaporation & chemical precipitation (B) Biological methods & adsorption in ion exchange materials (C) Fixing into a solid mass with cement and sinking deep in the sea (D) All (A), (B) & (C)

Description : What are the methods of treatment & disposal of radioactive wastes? (A) Evaporation & chemical precipitation (B) Biological methods & adsorption in ion exchange materials (C) Fixing into a solid mass with cement and sinking deep in the sea (D) All (A), (B) & (C)

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

A metal salt solution gives a yellow precipitate with silver nitrate. The precipitate dissolves in dilute nitric acid as well as in ammonium hydroxide

Description : A metal salt solution gives a yellow precipitate with silver nitrate. The precipitate dissolves in dilute nitric acid as well as in ammonium hydroxide

Last Answer : A metal salt solution gives a yellow precipitate with silver nitrate. The precipitate dissolves in dilute nitric acid as ... (3-)` D. `SO_(4)^(2-)`

Shravani was performing inorganic qualitative analysis of a salt. To an aqueous solution of that salt, she added silver nitrate.

Description : Shravani was performing inorganic qualitative analysis of a salt. To an aqueous solution of that salt, she added silver nitrate.

Last Answer : Shravani was performing inorganic qualitative analysis of a salt. To an aqueous solution ... observations and write the chemical reactions involved.

Brackish water which contains mostly dissolved salt, can be purified by the __________ process. (A) Reverse osmosis (B) Sand filter(C) Lime soda(D) Permutit

Description : Brackish water which contains mostly dissolved salt, can be purified by the __________ process. (A) Reverse osmosis (B) Sand filter (C) Lime soda (D) Permutit

Last Answer : (A) Reverse osmosis

What is observed when a solution of potassium iodide solution is added to a solution of lead nitrate? Name the type of reaction. Write a balanced chemical equation to represent the above chemical reaction. -Chemistry

Description : What is observed when a solution of potassium iodide solution is added to a solution of lead nitrate? Name the type of reaction. Write a balanced chemical equation to represent the above chemical reaction. -Chemistry

Last Answer : Answer.Yellow precipitate of lead iodide is formed. It is precipitation reaction. Pb( NO3)2 (aq) + 2KI (aq) —-> Pbl2 (s) + 2KNO3 (aq) It is also called double displacement reaction.

10.(a) An ore on treatment with dilute hydrochloric acid produces brisk effervesces. What type of ore is this? What steps will be required to obtain metal from the enriched ore. , (b) Copper coin is kept immersed in silver nitrate solution for some time. What change will take place in coin and colour of the solution ? Write balanced chemical equation of the reaction involved. -Chemistry

Description : 10.(a) An ore on treatment with dilute hydrochloric acid produces brisk effervesces. What type of ore is this? What steps will be required to obtain metal from the enriched ore. , (b) ... in coin and colour of the solution ? Write balanced chemical equation of the reaction involved. -Chemistry

Last Answer : (a) Carbonate ore: (i) Calcination: Carbonate ore is heated in limited supply of air and oxide is obtained, e.g. (b) Copper, being more reactive than silver will displace silver from silver nitrate ... and there will be deposition of silver on copper coin. The colour of solution will turn to blue.

Water gets evaporated from water surfaces and land surfaces, get converted into water drops at lower temperatures, flows over ground surface and finally meets its source, i.e. lake, sea, etc. This entire process is generally known as (A) Hydrological cycle (B) Water cycle (C) Evaporation and precipitation cycle (D) All the above

Description : Water gets evaporated from water surfaces and land surfaces, get converted into water drops at lower temperatures, flows over ground surface and finally meets its source, i.e. lake, sea, etc. This ... Hydrological cycle (B) Water cycle (C) Evaporation and precipitation cycle (D) All the above

Last Answer : (D) All the above

A thermoelectric engine which consists of two dissimilar electric conductors connected at two junctions maintained at different temperatures, converts (a) Electric energy into heat energy [IES-2006] (b) Heat energy into electric energy (c) Mechanical work into electric energy (d) Electric energy into mechanical work

Description : A thermoelectric engine which consists of two dissimilar electric conductors connected at two junctions maintained at different temperatures, converts (a) Electric energy into heat energy [IES-2006] (b ... energy (c) Mechanical work into electric energy (d) Electric energy into mechanical work  

Last Answer : (b) Heat energy into electric energy  

Is a methanol is burned and leaves a residue a chemical change?

Description : Is a methanol is burned and leaves a residue a chemical change?

Last Answer : Burning (an oxidation reaction) is a chemical change,

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 meant by skeltal type chemical equation? What does it represent? Using the equation for electrolytic decomposition of water, differentiate between a skeltal chemical equation and a balanced chemical equation. -Chemistry

Description : What is meant by skeltal type chemical equation? What does it represent? Using the equation for electrolytic decomposition of water, differentiate between a skeltal chemical equation and a balanced chemical equation. -Chemistry

Last Answer : Answer. The equations in which gaseous are written in atomic form instead of molecular form and equation is not balanced, are called skeltal type equation. They represent gaseous elements formed in atomic state and equation is not balanced

Furan reacts with ammonia in the presence of alumina at 400°C to give (a) Pyridine (b) Furfura(c) Pyrrole (d) Furoic acidl

Description : Furan reacts with ammonia in the presence of alumina at 400°C to give (a) Pyridine (b) Furfural (c) Pyrrole (d) Furoic acid

Last Answer : Pyrrole

When propyne is passed through hot iron tube at 400°C, it gives (a) Benzene(b) Toluene(c) m-Xylene(d) Mesitylene

Description : When propyne is passed through hot iron tube at 400°C, it gives (a) Benzene (b) Toluene (c) m-Xylene (d) Mesitylene

Last Answer : Mesitylene

When acetylene is passed through hot iron tube at 400°C, it gives (a) Benzene (b) Toluene (c) o-Xylene (d) Mesitylene

Description : When acetylene is passed through hot iron tube at 400°C, it gives (a) Benzene (b) Toluene (c) o-Xylene (d) Mesitylene

Last Answer : Benzene

Assertion A. : Discharging the effluents from the oxidation ponds just up stream of lakes or reservoirs is undesirable. Reason (R) : The discharged algae get settled in the reservoirs and cause anaerobic decomposition and other water qualities. A. Both A and R are true and R is the correct explanation of A B. Both A and R are true but R is not a correct explanation of A C. A is true but R is false D. A is false but R is true

Description : Assertion A. : Discharging the effluents from the oxidation ponds just up stream of lakes or reservoirs is undesirable. Reason (R) : The discharged algae get settled in the reservoirs and cause anaerobic decomposition and other ... of A C. A is true but R is false D. A is false but R is true

Last Answer : ANS: A

Which mineral is formed by decomposition of rocks, leaving a residual mass of weathered material ? -SST 10th

Description : Which mineral is formed by decomposition of rocks, leaving a residual mass of weathered material ? -SST 10th

Last Answer : Bauxite is a mineral which is formed by decomposition of rocks, leaving a residual mass of weathered material.

Which one of the following minerals is formed by decomposition of rocks, leaving a residual mass of weathered materials ? -SST 10th

Description : Which one of the following minerals is formed by decomposition of rocks, leaving a residual mass of weathered materials ? -SST 10th

Last Answer : B - Bauxite is formed after the decomposition of surface rocks. The soluble constituent within rocks evaporates and what is left behind as residue is the ore of Bauxite from which then Aluminium is extracted.

The gas produced in marshy places due to decomposition of vegetation is – (1) Carbon monoxide (2) Carbon dioxide (3) Sulphur dioxide (4) Methane

Description : The gas produced in marshy places due to decomposition of vegetation is – (1) Carbon monoxide (2) Carbon dioxide (3) Sulphur dioxide (4) Methane

Last Answer : (4) Methane Explanation: Methane gas is a hydrocarbon gas largely composed of methane formed when organic material or vegetation decays in the absence of air. Naturally occurring methane is mainly produced by the process of methanogenesis. It is also known as Swamp Gas.

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.