Leaching of `Ag_(2)S` is carried out by heating it with a dilute solution of:

Leaching of `Ag_(2)S` is carried out by heating it with a dilute solution of:
by

1 Answer

Answer :

Leaching of `Ag_(2)S` is carried out by heating it with a dilute solution of: A. NaCN only B. HCl C. NaOH D. NaCN in presence of `O_(2)`
by
selected by

Related questions

In the leaching of `Ag_(2)S` with `NaCN`, a stream air is also passed. It is because of

Description : In the leaching of `Ag_(2)S` with `NaCN`, a stream air is also passed. It is because of

Last Answer : In the leaching of `Ag_(2)S` with `NaCN`, a stream air is also passed. It is because of A. reversible ... C. both (A) and (B) D. none of the above

Statement-1: Extraction of gold from its native ore involves leaching the metal wih dilute solution of NaCN in presence of air. Statement-2:This is an

Description : Statement-1: Extraction of gold from its native ore involves leaching the metal wih dilute solution of NaCN in presence of air. Statement-2:This is an

Last Answer : Statement-1: Extraction of gold from its native ore involves leaching the metal wih dilute solution of ... -1 is false but Statement -2 is true

Assertion: `Ag` and `Au` are extracted by leaching the ores with a dilute solution of `NaCN`. Reason: Impurities associated with these ores dissolve i

Description : Assertion: `Ag` and `Au` are extracted by leaching the ores with a dilute solution of `NaCN`. Reason: Impurities associated with these ores dissolve i

Last Answer : Assertion: `Ag` and `Au` are extracted by leaching the ores with a dilute solution of `NaCN`. ... . Statement-1 is false but Statement -2 is true

Coffee is prepared from coffee beans by leaching with (A) Cold water (B) Hot water (C) Dilute hot caustic solution (D) Naphtha

Description : Coffee is prepared from coffee beans by leaching with (A) Cold water (B) Hot water (C) Dilute hot caustic solution (D) Naphtha

Last Answer : (B) Hot water

A process stream of dilute aqueous solution flowing at the rate of10 Kg.s -1 is to be heated. Steam condensate at 95°C is available for heating purpose, also at a rate of 10 Kg.s -1 . A 1 - 1 shell and tube heat exchanger is available. The best arrangement is (A) Counter flow with process stream on shell side (B) Counter flow with process stream on tube side (C) Parallel flow with process stream on shell side (D) Parallel flow with process stream on tube side

Description : A process stream of dilute aqueous solution flowing at the rate of10 Kg.s -1 is to be heated. Steam condensate at 95°C is available for heating purpose, also at a rate of 10 Kg.s -1 . A 1 ... side (C) Parallel flow with process stream on shell side (D) Parallel flow with process stream on tube side

Last Answer : (A) Counter flow with process stream on shell side

Leaching of sugar from sugar beets is done by (A) Hot water (B) Hexane (C) Dilute H2SO4 (D) Lime water

Description : Leaching of sugar from sugar beets is done by (A) Hot water (B) Hexane (C) Dilute H2SO4 (D) Lime water

Last Answer : (A) Hot water

Leaching of coffee from coffee beans is done by (A) Hot water (B) Hexane (C) Lime water (D) Dilute H2SO4 (hot)

Description : Leaching of coffee from coffee beans is done by (A) Hot water (B) Hexane (C) Lime water (D) Dilute H2SO4 (hot)

Last Answer : (A) Hot water

What concentration of `Ag^(+)` ions will be in equilibrium with a saturated solution containing a precipitate of `Ag_(2)CrO_(4) and CrO_(4)`-ion conce

Description : What concentration of `Ag^(+)` ions will be in equilibrium with a saturated solution containing a precipitate of `Ag_(2)CrO_(4) and CrO_(4)`-ion conce

Last Answer : What concentration of `Ag^(+)` ions will be in equilibrium with a saturated solution containing a precipitate of ... D. `5.9xx10^(-6)` moles per litre

Which one of the following processes during decomposition is correctly described? (a) Catabolism – Last step in the decomposition under fully anaerobic condition (b) Leaching – Water soluble inorganic nutrients rise to the top layers of soil (c) Fragmentation – Carried out by organisms such as earthworm (d) Humification – Leads to the accumulation of a dark coloured substance humus which undergoes microbial action at a very fast rate.

Description : Which one of the following processes during decomposition is correctly described? (a) Catabolism - Last step in the decomposition under fully anaerobic condition (b) Leaching - Water soluble inorganic ... of a dark coloured substance humus which undergoes microbial action at a very fast rate.

Last Answer : (c) Fragmentation – Carried out by organisms such as earthworm

The process by which nutrient chemicals or contaminants are dissolved and carried away by water, or are moved into a lower layer of soil (a) mulching (b) desertification (c) incineration (d) leaching

Description : The process by which nutrient chemicals or contaminants are dissolved and carried away by water, or are moved into a lower layer of soil (a) mulching (b) desertification (c) incineration (d) leaching

Last Answer : (d) leaching

The process by which nutrient chemicals or contaminants are dissolved and carried away by water, or are moved into a lower layer of soil a) Mulching b) Desertification c) Incineration d) Leaching

Description : The process by which nutrient chemicals or contaminants are dissolved and carried away by water, or are moved into a lower layer of soil a) Mulching b) Desertification c) Incineration d) Leaching

Last Answer : d) Leaching

Out of `Cu_(2)S,HgS,Ag_(2)S` and ZnS roasting will convert the mineral in to metal case of

Description : Out of `Cu_(2)S,HgS,Ag_(2)S` and ZnS roasting will convert the mineral in to metal case of

Last Answer : Out of `Cu_(2)S,HgS,Ag_(2)S` and ZnS roasting will convert the mineral in to metal case of A. `Cu_(2)S,Zns` B. Hgs,ZnS C. `Cu_(2)S,Ag_(2)S` D. HgS

For the reaction `Ag_(2)O(s)rarr 2Ag(s)+1//2O_(2)(g)` the value of `Delta H=30.56 KJ mol^(_1)` and `Delta S = 66 JK^(-1)mol^(-1)`. The temperature at

Description : For the reaction `Ag_(2)O(s)rarr 2Ag(s)+1//2O_(2)(g)` the value of `Delta H=30.56 KJ mol^(_1)` and `Delta S = 66 JK^(-1)mol^(-1)`. The temperature at

Last Answer : For the reaction `Ag_(2)O(s)rarr 2Ag(s)+1//2O_(2)(g)` the value of `Delta H=30.56 KJ mol^(_1)` and `Delta ... :- A. 373 K B. 413 K C. 463 K D. 493 K

The temperature at which the reaction : `Ag_(2)O(s)rarr 2Ag(s)+1//2O_(2)(g)` is at equilibrium is …….., Given `Delta H=30.5 KJ mol^(-1)` and `Delta S

Description : The temperature at which the reaction : `Ag_(2)O(s)rarr 2Ag(s)+1//2O_(2)(g)` is at equilibrium is …….., Given `Delta H=30.5 KJ mol^(-1)` and `Delta S

Last Answer : The temperature at which the reaction : `Ag_(2)O(s)rarr 2Ag(s)+1//2O_(2)(g)` is at equilibrium is .., ... 362.12 K` C. `262.12 K` D. `562.12 K`

For the reaction `Ag_(2)O(s)rarr 2Ag(s)+1//2O_(2)(g)`, which one of the following is true :

Description : For the reaction `Ag_(2)O(s)rarr 2Ag(s)+1//2O_(2)(g)`, which one of the following is true :

Last Answer : For the reaction `Ag_(2)O(s)rarr 2Ag(s)+1//2O_(2)(g)`, which one of the following is true : A. ` ... . `Delta H lt Delta H` D. `Delta H gt Delta E`

Extraction of silver from `Ag_(2)S` by the use of sodium cyanide is example of

Description : Extraction of silver from `Ag_(2)S` by the use of sodium cyanide is example of

Last Answer : Extraction of silver from `Ag_(2)S` by the use of sodium cyanide is example of A. `NaSO_(4)` B. `Na_(2)S` C. `2Na[Ag(CN)_(2)]` D. `Na_(2)ZnSO_(4)`

`Ag_(2)S` ore Is mixed with NaCl and heated in the presence of air then products formed are

Description : `Ag_(2)S` ore Is mixed with NaCl and heated in the presence of air then products formed are

Last Answer : `Ag_(2)S` ore Is mixed with NaCl and heated in the presence of air then products formed are A. `AgCl+Na_(2)SO_( ... S` C. `AgCl+SO_(2)` D. `Ag+SO_(2)`

`Ag_(2)S +NaCN rarr (a)` (a) `+Zn rarr (d)` (b) is a metal. Hence `(a)` and `(b)` are

Description : `Ag_(2)S +NaCN rarr (a)` (a) `+Zn rarr (d)` (b) is a metal. Hence `(a)` and `(b)` are

Last Answer : `Ag_(2)S +NaCN rarr (a)` (a) `+Zn rarr (d)` (b) is a metal. Hence `(a)` and `(b)` are A. `Na_(2)[Zn( ... )[Ag(CN)_(4)],Ag` D. `Na_(3)[Ag(CN)_(4)],Ag`

If a dilute solution of aqueous `NH_(3)` is saturated with `H_(2)S` then the product formed is :

Description : If a dilute solution of aqueous `NH_(3)` is saturated with `H_(2)S` then the product formed is :

Last Answer : If a dilute solution of aqueous `NH_(3)` is saturated with `H_(2)S` then the product formed is : A. `(NH_(4))_( ... (NH_(4))_(2)S_(x)` D. `NH_(4)OH+S`

On passing H2 S through dilute HNO3 the colourless solution becomes turbid. Why ?

Description : On passing H2 S through dilute HNO3 the colourless solution becomes turbid. Why ? 

Last Answer : Ans. Due to formation of colloidal sol of Sulphur. 

Stage efficiency in a leaching process depends on the (A) Time of contact between the solid and the solution (B) Rate of diffusion of the solute through the solid and into the liquid (C) Both (A) and (B) (D) Vapour pressure of the solution

Description : Stage efficiency in a leaching process depends on the (A) Time of contact between the solid and the solution (B) Rate of diffusion of the solute through the solid and into the liquid (C) Both (A) and (B) (D) Vapour pressure of the solution

Last Answer : (C) Both (A) and (B)

Which of the following operations does not involve leaching? (A) Dissolving gold from ores (B) Dissolving pharmaceutical products from bark or roots (C) Dissolving sugar from the cells of the beet (D) Removing nicotine from its water solution by kerosene

Description : Which of the following operations does not involve leaching? (A) Dissolving gold from ores (B) Dissolving pharmaceutical products from bark or roots (C) Dissolving sugar from the cells of the beet (D) Removing nicotine from its water solution by kerosene

Last Answer : (D) Removing nicotine from its water solution by kerosene

Which of the following solvents is used for the extraction of H3PO4 from CaCl2 solution during manufacture of ortho-phosphoric acid by wet process employing hydrochloric acid leaching? (A) Isopropyl alcohol (B) Butyl alcohol (C) Toluene (D) Hexane

Description : Which of the following solvents is used for the extraction of H3PO4 from CaCl2 solution during manufacture of ortho-phosphoric acid by wet process employing hydrochloric acid leaching? (A) Isopropyl alcohol (B) Butyl alcohol (C) Toluene (D) Hexane

Last Answer : (B) Butyl alcohol

Role of hydrogen peroxide iin the following reaction is respectively. `(i)" " H_(2)O_(2) +O_(3) rarr H_(2)O+ZO_(2)` `(ii)" " H_(2)O_(2)+Ag_(2)Orarr Aa

Description : Role of hydrogen peroxide iin the following reaction is respectively. `(i)" " H_(2)O_(2) +O_(3) rarr H_(2)O+ZO_(2)` `(ii)" " H_(2)O_(2)+Ag_(2)Orarr Aa

Last Answer : Role of hydrogen peroxide iin the following reaction is respectively. `(i)" " H_(2)O_(2) +O_(3) rarr H_ ... in II D. oxidising in I as well as in II

`CH_(3)CH=CH_(2)overset(HCI)rarrXoverset(Dry Ag_(2)O)underset(Heat)rarrY` The product Y in the above sequence is

Description : `CH_(3)CH=CH_(2)overset(HCI)rarrXoverset(Dry Ag_(2)O)underset(Heat)rarrY` The product Y in the above sequence is

Last Answer : `CH_(3)CH=CH_(2)overset(HCI)rarrXoverset(Dry Ag_(2)O)underset(Heat)rarrY` The product Y in the above ... ether C. 2- proponal D. 1, 2- Epoxypropane

Match the following `{:("List I","ListII"),("(A) Feldspar",(I) [Ag_(3)SbS_(3)]),("(B) Asbestors",(II) Al_(2)O_(3)H_(2)O),("(C) Pyrargyrite",(III) MgSO

Description : Match the following `{:("List I","ListII"),("(A) Feldspar",(I) [Ag_(3)SbS_(3)]),("(B) Asbestors",(II) Al_(2)O_(3)H_(2)O),("(C) Pyrargyrite",(III) MgSO

Last Answer : Match the following `{:("List I","ListII"),("(A) Feldspar",(I) [Ag_(3)SbS_(3)]),("(B) Asbestors",(II) Al_(2)O_( ... (,(A),(B),(C),(D)),(,II,V,IV,I):}`

Which is a mutual reduction reaction ? A) `KMnO_(4)+O_(3)` B) `H_(2)O_(2)+O_(3)` C) `Ag_(2)O+O_(3)` D) `KI+H_(2)O+O_(3)`

Description : Which is a mutual reduction reaction ? A) `KMnO_(4)+O_(3)` B) `H_(2)O_(2)+O_(3)` C) `Ag_(2)O+O_(3)` D) `KI+H_(2)O+O_(3)`

Last Answer : Which is a mutual reduction reaction ? A) `KMnO_(4)+O_(3)` B) `H_(2)O_(2)+O_(3)` C) `Ag_(2)O+O_(3)` D) `KI+H_(2)O+O_(3)` A. A,B B. A,C C. A,D D. B,C

Pick out the wrong statement. (A) The mole fraction of solute is directly proportional to the molality of a 'dilute' solution (B) For a non-reacting binary mixture of ideal gases, the partial pressure distribution of both components is nonlinear in the case of steady state unimolal unidirectional diffusion (C) Azeotropes obey Raoult's law at all temperature (D) The relative volatility of a binary mixture at the Azeotropic composition is 1

Description : Pick out the wrong statement. (A) The mole fraction of solute is directly proportional to the molality of a 'dilute' solution (B) For a non-reacting binary mixture of ideal gases, the partial ... at all temperature (D) The relative volatility of a binary mixture at the Azeotropic composition is 1

Last Answer : (C) Azeotropes obey Raoult's law at all temperature

In case of staged packed bed reactors carrying out exothermic reaction, use (A) High recycle for pure gas (B) Plug flow for dilute liquid requiring no large preheating of feed (C) Cold shot operations for a dilute solution requiring large preheating to bring the stream upto the reaction temperature (D) All (A), (B) and (C)

Description : In case of staged packed bed reactors carrying out exothermic reaction, use (A) High recycle for pure gas (B) Plug flow for dilute liquid requiring no large preheating of feed (C) Cold shot operations for a ... preheating to bring the stream upto the reaction temperature (D) All (A), (B) and (C)

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

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.

When chlorine reacts with cold and dilute solution of sodium hydroxide, the products obtained are

Description : When chlorine reacts with cold and dilute solution of sodium hydroxide, the products obtained are

Last Answer : When chlorine reacts with cold and dilute solution of sodium hydroxide, the products obtained are A. (1) `ClO_2^ ... ClO_2^-` D. `ClO^-` and `ClO_3^-`

Hydrogen peroxide solution `(20 mL)` reacts quantitatively with a solution of `KMnO_(4) (20 mL)` acidified with dilute of `H_(2)SO_(4)`. The same volu

Description : Hydrogen peroxide solution `(20 mL)` reacts quantitatively with a solution of `KMnO_(4) (20 mL)` acidified with dilute of `H_(2)SO_(4)`. The same volu

Last Answer : Hydrogen peroxide solution `(20 mL)` reacts quantitatively with a solution of `KMnO_(4) (20 mL)` ... calculate the molarity of `H_(2)O_(2)`.

A dilute solution of `H_(2)SO_(4)` is made by adding 5 mL of `3N H_(2)SO_(4)` to 245 mL of water. Find the normality and molarity of the diluted solut

Description : A dilute solution of `H_(2)SO_(4)` is made by adding 5 mL of `3N H_(2)SO_(4)` to 245 mL of water. Find the normality and molarity of the diluted solut

Last Answer : A dilute solution of `H_(2)SO_(4)` is made by adding 5 mL of `3N H_(2)SO_(4)` ... of water. Find the normality and molarity of the diluted solution.

A salt solution of `Cd^(2+)` in dilute HCl, on treatment with a solution of `BaCl_(2)` gives a white precipitate, which is insoluble in concentrated `

Description : A salt solution of `Cd^(2+)` in dilute HCl, on treatment with a solution of `BaCl_(2)` gives a white precipitate, which is insoluble in concentrated `

Last Answer : A salt solution of `Cd^(2+)` in dilute HCl, on treatment with a solution of `BaCl_(2)` gives a white precipitate, ... C. `NO_(2)^(-)` D. `S^(2-)`

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-)`

Oxygen and hydrogen gases are produced at the anode and cathod erespectively during electrolysis of dilute aq. Solution of

Description : Oxygen and hydrogen gases are produced at the anode and cathod erespectively during electrolysis of dilute aq. Solution of

Last Answer : Oxygen and hydrogen gases are produced at the anode and cathod erespectively during electrolysis of dilute aq. Solution ... (3)` C. HCl D. `CuSO_(4)`

When you check the specific gravity of the battery electrolyte with a hydrometer, it should be kept in mind that ____________. A. the battery is fully charged when the indicator floats low in the electrolyte B. any water that has been previously added to the cells will dilute the solution and give a false reading C. a hydrometer reading is inaccurate if taken immediately after water is added to the cell D. temperature has no effect on hydrometer readings

Description : When you check the specific gravity of the battery electrolyte with a hydrometer, it should be kept in mind that ____________. A. the battery is fully charged when the indicator floats low in ... taken immediately after water is added to the cell D. temperature has no effect on hydrometer readings

Last Answer : Answer: C

Diffusivity in concentrated solutions differs from that in dilute solutions, because of the changes in (A) Viscosity with concentration (B) Degree of ideality of the solution (C) Both (A) and (B) (D) Neither (A) nor (B)

Description : Diffusivity in concentrated solutions differs from that in dilute solutions, because of the changes in (A) Viscosity with concentration (B) Degree of ideality of the solution (C) Both (A) and (B) (D) Neither (A) nor (B)

Last Answer : (C) Both (A) and (B)

Diffusion in concentrated solutions differs from that in dilute solutions, because of the change in the __________ with the concentration of the solution. (A) Degree of ideality (B) Viscosity (C) Both 'a '& 'b' (D) Neither 'a' nor 'b'

Description : Diffusion in concentrated solutions differs from that in dilute solutions, because of the change in the __________ with the concentration of the solution. (A) Degree of ideality (B) Viscosity (C) Both 'a '& 'b' (D) Neither 'a' nor 'b'

Last Answer : (C) Both 'a '& 'b

The overall mass transfer co-efficient for the absorption of SO2 in air with dilute NaOH solution can be increased substantially by (A) Increasing the gas film co-efficient(B) Increasing the liquid film co-efficient(C) Increasing the total pressure(D) Decreasing the total pressure

Description : The overall mass transfer co-efficient for the absorption of SO2 in air with dilute NaOH solution can be increased substantially by (A) Increasing the gas film co-efficient (B) Increasing the liquid film co-efficient (C) Increasing the total pressure (D) Decreasing the total pressure

Last Answer : (A) Increasing the gas film co-efficient

Which of the following is a suitable absorbent for removal of H2S from natural gas? (A) Vetrocoke solution (B) Monoethanolamine (MEA) (C) Dilute (D) Hot water

Description : Which of the following is a suitable absorbent for removal of H2S from natural gas? (A) Vetrocoke solution (B) Monoethanolamine (MEA) (C) Dilute (D) Hot water

Last Answer : (B) Monoethanolamine (MEA)

For an absorber, both equilibrium and operating line will be straight for (A) Concentrated solution and non-isothermal operation (B) Dilute solution and non-isothermal operation (C) Dilute solution and isothermal operation (D) Concentrated solution and isothermal operation

Description : For an absorber, both equilibrium and operating line will be straight for (A) Concentrated solution and non-isothermal operation (B) Dilute solution and non-isothermal operation (C) Dilute solution and isothermal operation (D) Concentrated solution and isothermal operation

Last Answer : (C) Dilute solution and isothermal operation

Acetic acid will be most economically separated from a dilute solution of acetic acid in water by (A) Solvent extraction (B) Continuous distillation (C) Evaporation (D) Absorption

Description : Acetic acid will be most economically separated from a dilute solution of acetic acid in water by (A) Solvent extraction (B) Continuous distillation (C) Evaporation (D) Absorption

Last Answer : (A) Solvent extraction

What happens when freshly precipitated Fe (OH)3 is shaken with a little amount of dilute solution of FeCl3 ?

Description : What happens when freshly precipitated Fe (OH)3 is shaken with a little amount of dilute solution of FeCl3 ?

Last Answer : Ans. It causes peptization leading to the formation of a positively charged sol of Fe (OH)3 

What is expected value of ‘i’ for K4[Fe(CN)6] in dilute solution?

Description : What is expected value of ‘i’ for K4[Fe(CN)6] in dilute solution?

Last Answer : Ans:- Expected value of n in K4(Fe(CN)6) is 5. 

Ammonia present in the coke oven gas is removed by washing with (A) Caustic solution (B) Dilute ammoniacal liquor (C) Dilute HCl (D) Ethanolamine

Description : Ammonia present in the coke oven gas is removed by washing with (A) Caustic solution (B) Dilute ammoniacal liquor (C) Dilute HCl (D) Ethanolamine

Last Answer : (B) Dilute ammoniacal liquor

Strips of newspaper, filter paper and glazed paper are dipped in dilute potassium permanganate solution. Which paper will have absorbed more potassium permanganate?

Description : Strips of newspaper, filter paper and glazed paper are dipped in dilute potassium permanganate solution. Which paper will have absorbed more potassium permanganate?

Last Answer : The level of potassium permanganates in filter paper will be maximum as is more porous.

. A dilute aqueous solution is to be concentrated in an evaporator system. High pressure steam is available. Multiple effect evaporator system is employed, because (A) Total heat transfer area of all the effects is -less than that in a single effect evaporator system (B) Total amount of vapor produced per Kg of feed steam in a multiple effect system is much higher than in a single effect (C) Boiling point elevation in a single effect system is much higher than that in any effect in a multi-effect system (D) Heat transfer co-efficient in a single effect is much lower than that in any effect in a multi-effect system

Description : . A dilute aqueous solution is to be concentrated in an evaporator system. High pressure steam is available. Multiple effect evaporator system is employed, because (A) Total heat transfer area of ... in a single effect is much lower than that in any effect in a multi-effect system

Last Answer : (B) Total amount of vapor produced per Kg of feed steam in a multiple effect system is much higher than in a single effect

In flue gas analysis by Orsat's apparatus, carbon dioxide is absorbed by (A) Potassium hydroxide (B) Dilute potassium carbonate (C) Cuprous chloride (D) Alkaline pyrogallol solution

Description : In flue gas analysis by Orsat's apparatus, carbon dioxide is absorbed by (A) Potassium hydroxide (B) Dilute potassium carbonate (C) Cuprous chloride (D) Alkaline pyrogallol solution

Last Answer : (A) Potassium hydroxide