Ammonia ICSE Class-10 Concise Chemistry Selina Solutions
Study of Compound B- Ammonia Chapter-9 Selina Publications
Ammonia ICSE Class-10 Concise Chemistry Selina Solutions Chapter-9 Study of Compound B. We Provide Step by Step Answer of Intext , Exe-8 and Previous Year Questions of Chapter-9 Ammonia Study of Compound-B ICSE Class-10 . Visit official Website CISCE for detail information about ICSE Board Class-10.
Ammonia ICSE Class-10 Concise Chemistry Selina Solutions Chapter-9 Study of Compound-B
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How to solve Ammonia in Chemistry for ICSE Class 10
Read the Chapter -9 Ammonia Study of Compound-B carefully.Focus on reaction involve in Chemical Properties of Ammonia. Various Step involve in Purification of Ammonia Gas. Uses of Inverted Funnel in Ammonia . Lab Preparation of Ammonia Gas. Use of Fountain Experiment . For more practice on Ammonia try to solve exercise of other publications such as Goyal Brothers Prakshan / new Simplified Dr Dalal Chemistry.
Intext , Ammonia Selina Concise Solutions ICSE Chemistry for Class 10th
(a) State the type of bonding present in ammonia, show by a diagram?
(b) What is the formula of liquid ammonia? Account for the basic nature of this compound.
(a) Covalent bonding is present in ammonia.
(b) Formula of liquid ammonia is: NH3.
Liquid ammonia is liquefied ammonia and is basic in nature. It dissolves in water to give ammonium hydroxide which ionizes to give hydroxyl ions.
NH3 + H2O NH4OH
NH4OH NH4++ OH–
Therefore it turns red litmus blue and phenolphthalein solution pink.
(a) Write a balanced chemical equation for the lab preparation of ammonia.
(b) How is ammonia dried and collected in the laboratory?
(c) Why conc. H2SO4 is not used to dry ammonia
(d) Ammonia cannot be collected over water. Give reason.
(a) Lab preparation of ammonia:
2NH4Cl+Ca(OH)2 CaCl2 +2H2O +2NH3
(b) The ammonia gas is dried by passing through a drying tower containing lumps of quicklime (CaO).
(c) Other drying agents like conc. sulphuric acid, phosphorus pentaoxide and anhydrous calcium chloride are not used, as ammonia being basic, reacts with them.
(d) Ammonia is highly soluble in water and therefore it cannot be collected over water.
(a) Explain with a diagram the preparation of aqueous ammonia.
(b) Why are other drying agents such as P2O5 and CaCl2 not used to dry NH3
(a) An aqueous solution of ammonia is prepared by dissolving ammonia in water. The rate of dissolution of ammonia to water is very high.
(b)The drying agent used is CaO in case of ammonia.
Other drying agents like P2O5 and CaCl2 are not used. As ammonia being basic reacts with them.
6NH3 + P2O5 +3H2O 2(NH4)3PO4
CaCl2 +4NH3 CaCl2.4NH3
A substance ‘A’ was heated with slaked lime and a gas ‘B’ with pungent smell was obtained. Name the substances A and B and give a balanced equation.
The substance A is Ammonium chloride and ‘B’ is Ammonia.
2NH4Cl + Ca(OH)2 CaCl2 + 2H2O + 2NH3
Ammonia is manufactured by Haber Process.
(a) Under what conditions do the reactants combine to form ammonia? Give a balanced equation for the reaction.
(b) In what ratio by volume, are the above gases used?
(c) State one possible source of each reactant used in Haber process.
(d) State whether the formation of ammonia is promoted by the use of high pressure or low pressure?
(e) Mention two possible ways by which ammonia produced is removed from unchanged gases.
(f) What is the function of:
(i) Finely divided iron
(ii) Molybdenum in the above process
(g) What is the percentage formation of ammonia?
(h) How can this percentage formation be increased?
(a) Conditions for reactants to combine :
Optimum temperature is 450o-500oC
Above 200 atm pressure
Finely divided iron as catalyst
Traces of molybdenum or Al2O3 as promoters.
Reaction: N2 +3H2 2NH3 + heat
(b) Dry nitrogen and dry hydrogen in the ratio of 1:3 by volume is made to combine.
(c) Source of Hydrogen: Hydrogen is generally obtained from water gas by Bosch process.
(CO + H2) + H2O CO2 +2H2
Source of Nitrogen: It is obtained from fractional distillation of liquid air.
(d) High pressure favours the forward reaction i.e. formation of ammonia.
(e) Two possible ways by which NH3 produced is removed from unreacted N2 and H2 by:
(i) Liquefaction: NH3 is easily liquefiable.
(ii) Absorbing in water: As ammonia is highly soluble in water.
(i) Finely divided iron increases the rate of reaction.
(ii) Molybdenum acts as a promoter to increase the efficiency of the catalyst.
(h) The unchanged nitrogen and hydrogen are recirculated through the plant to get more ammonia. By recirculating in this way, an eventual yield of 98% can be achieved.
(a) Ammonium compounds do not occur as minerals.
(b) Ammonium nitrate is not used in the preparation of ammonia.
(c) Conc. H2SO4 is a good drying agent, yet it is not used to dry NH3.
(d) In the lab. preparation of ammonia
(i) calcium hydroxide is used in excess
(ii) a flask is fitted in slanting position
(a) Ammonium compounds being highly soluble in water do not occur as minerals.
(b) Ammonium nitrate is not used in the preparation of ammonia as it is explosive in nature and it decomposes forming nitrous oxide and water vapours.
(c) Conc. H2SO4 is not used to dry ammonia, as ammonia being basic reacts with them.
2NH3 + H2SO4 (NH4)2SO4
(d) (i) In order to better mixing of ammonium chloride, calcium hydroxide used in excess.
(ii) The flask is fitted in slatting position because of the water formed in the reaction does not trickle back into the heated flask.
(a) Complete the table.
|Name of process||Inputs||Equations||Output|
(b) State the following conditions required in the above process
|Name of process||Inputs||Equations||Output|
|Haber’s process||Nitrogen and hydrogen||Ammonia|
(i) 450 – 500°C
(ii) 200 -800 atm
(iii) Finely divided iron (Fe)
Choose the correct word or phrase from the brackets to complete the following sentences and write balanced equations for the same.
(a) Ammonium chloride is a soluble salt prepared by ………… [precipitation,neutralisation].
(b) When ammonium chloride is heated, it undergoes ………… [thermaldecomposition/dissociation].
(c) Heating ammonium chloride with sodium hydroxide produces ………… [ammonia, nitrogen].
(b) Thermal decomposition
An element has 2 electrons in its N shell. It reacts with a non-metal of atomic number 7. The compound formed reacts with warm water and produces a basic gas. Identify the elements and write the balanced chemical reaction.
An element has 2 electrons in its N shell = Ca (calcium)
It reacts with a non-metal of atomic number 7 = N (nitrogen)
The compound formed is calcium nitride (Ca3N2) which reacts with warm water and produces the basic gas ammonia (NH3).
Correct the following:
(a) A reddish brown precipitate is obtained when ammonium hydroxide is added to ferroussulphate.
(b) Liquid ammonia is a solution of NH3.
(c) Finely divided platinum is used in the Haber process.
(d) Conc. H2SO4is a drying agent for NH3.
(e) Ammonium salts, on heating, decompose to give ammonia.
(a) A reddish brown precipitate is obtained when ammonium hydroxide is added to ferrouschloride.
(b) Aqueousammonia is a solution of NH3.
(c) Finely dividediron is used in Haber process.
(d) Quicklime (CaO)is a drying agent for NH3.
(e) Ammonium salts, on thermal decomposition, give ammonia and hydrogen chloride.
Exercise-9 , Ammonia Selina Concise Solutions of ICSE Class-10 Chemistry
(a) Is ammonia more dense or less dense than air?
(b) What property of ammonia is demonstrated by Fountain Experiment? (c)Write the balanced equation for the reaction between ammonia and sulphuric acid.
(c) Write the balanced equation for the reaction between ammonia and sulphuric acid.
(a) Ammonia is less dense than air. By Fountain Experiment, we demonstrate the high solubility of ammonia gas in water.
(b) The high solubility of ammonia gas in water
(c) The balanced equation for the reaction between ammonia and sulphuric acid is:
2NH3 + H2SO4 (NH4)2SO4
Pick the odd member from the list giving reasons:
(a) Ammonia, sulphur dioxide, Hydrogen chloride, carbon dioxide.
(b) Copper oxide, Aluminium oxide, sodium oxide, Magnesium oxide.
(a) Ammonia is basic in nature.
(b) Copper oxide because CuO is less reactive can be reduced by C, CO or by hydrogen whereas Al2O3, Na2O, MgO are reduced by electrolysis.
The following reactions are carried out:
A : Nitrogen + metal compound X
B: X+ water ammonia +another compound
C: Ammonia + metal oxide metal + water + N2
One metal that can be used for reaction A is magnesium.
(a) Write the formula of the compound X formed.
(b) Write the correctly balanced equation for reaction B where X is the compound formed.
(c) What property of ammonia is demonstrated by reaction C?
(a) The formula of the compound is Mg3N2.
(b) Balanced equation :
Mg3N2 + 6 H2O 3 Mg(OH)2 + 2 NH3
(c) Ammonia is a reducing agent and reduces less active metal oxide to its respective metal.
A gas ‘P’ gives dense white fumes with chlorine. Its aqueous solution gives a blue colour with copper (II) hydroxide. (a) Name the gas P. (b) Give its formula. (c) Give three uses of P.
(a) The gas is ammonia.
(b) The formula is NH3.
(c) Uses of ammonia:
Ammonia is used in the industrial preparation of nitric acid by Ostwald process.
The ammonia used in the manufacture of fertilizers such as ammonium sulphate, ammonium nitrate, ammonium phosphate.
It manufacture sodium carbonate by Solvay process ammonia is used.
NaCl + NH3 + CO2 + H2O NaHCO3 +NH4Cl
Ammonia solution in water gives a blue precipitate when it combines with a solution of copper salt. The blue precipitate further dissolves in excess of ammonia solution to give azure blue solution. Explain with equation.
CuSO4 +2NH4OH Cu(OH)2 + [NH4]2SO4
Ammonia solution in water gives a blue precipitate when it combines with a solution of copper salt.
The pale blue precipitate of copper hydroxide dissolves in excess of ammonium hydroxide forming tetraamine copper[II] sulphate, an azure blue(deep blue)soluble complex salt.
Cu(OH)2 +(NH4)2SO4 +2NH4OH [Cu(NH3)4]SO4 + 4H2O
Give chemical equation (s) to prove that NH3 contains nitrogen and hydrogen.
This reaction is reversible and exothermic. From the reaction, it is proved that ammonia contains nitrogen and hydrogen.
Ammonia burns with a yellowish flame. It produces water vapour and nitrogen. This shows that ammonia contains nitrogen and hydrogen.
Copy and complete the following equations:
(a) AlN + H2O
(b) 2NH3 + 3PbO
(c) NH3 +3Cl2
(d) NH3 + CO2
(i) Which property of ammonia is illustrated by equation (c)?
(ii) What important fertilizer is prepared from equation (d)? State the conditions
(a) AlN + 3H2O Al(OH)3 +NH3
(b) 2NH3 + 3PbO 3Pb + 3H2O + N2
(c) 8NH3 +3Cl2 N2 + 6NH4Cl
(d) 2NH3 + CO2 NH2CONH2 + H2O
(i) Ammonia act as reducing agent is explained by equation (c).
(ii) Urea the nitrogenous fertilizer is prepared from equation (d).
What do you observe when ammonium hydroxide is added to the aqueous solution of:
(c) Lead nitrate
(a) Dirty green ppt. of Ferrous hydroxide is formed which is insoluble in excess of NH4OH.
FeSO4 + 2NH4OH [NH4]2SO4 + Fe(OH)2
(b) Reddish brown ppt. of ferric hydroxide is formed which is insoluble in ammonium hydroxide.
FeCl3 + 3NH4OH 3NH4Cl + Fe(OH)3
(c) White ppt. of lead hydroxide is formed which is insoluble in NH4OH.
Pb(NO3)2 + 2NH4OH 2NH4NO3 + Pb(OH)2
(d) White gelatinous ppt. of Zinc hydroxide is formed which is soluble in NH4OH.
Zn(NO3)2 + 2NH4OH 2NH4NO3 + Zn(OH)2
Give a chemical test to distinguish between the following:
(a) Ammonium chloride and sodium chloride
(b) Ferric salt and ferrous salt
(c) Sodium sulphate and ammonium sulphate
(a) NH4Cl NH3 + HCl
NH4Cl on strong heating sublimes to form dense white fumes which condense to white powdery mass on cooler parts of the tube whereas no white fumes on heating NaCl.
(b) When ammonium hydroxide is added drop wise to solution to be tested.
Ferrous salt gives dirty green ppt.
Ferric salt gives reddish brown ppt of their hydroxides.
(c) (NH4)2SO4 on warming with NaOH sol. gives NH3 gas. Sodium sulphate does not liberate NH3 gas.
Give the balanced equations for the following conversions:
(a) Ammonia to nitrogen using an acidic gas
(b) Ammonia to brown gas
(c) Ammonia to nitrogen trichloride
(d) Ammonia solution to an amphoteric hydroxide
(e) A nitride of a trivalent metal to ammonia
(f) Lead oxide to lead
Balanced equations :
(a) 8NH3 + 3Cl2 N2 + 6NH4Cl
(b) 4NH3 + 5O2 4NO +6H2O +Heat
(c) NH3 +3Cl2 3HCl +NCl3
(d) AlCl3 +3NH4OH 3NH4Cl + Al(OH)3
(e) AlN + 3H2O Al(OH)3 + NH3
(f) 3PbO +2NH3 3Pb + 3H2O +N2
(a) The gas which is prepared by Haber’s process
(b) Two gases which give dense white fumes with ammonia
(c) One salt of ammonia in each case which is used in :
(i) Dry cell (ii) explosives (iii) medicine.
(d) An acidic gas which reacts with basic gas liberating a neutral gas.
(e) A metallic chloride soluble in ammonium hydroxide.
(f) The gas obtained when ammonia burns in an atmosphere of oxygen without any catalyst.
(g) A nitride of a divalent metal which reacts with warm water liberating ammonia.
(h) An amphoteric oxide reduced by the basic gas.
(i) A white salt produced by an acid gas and a basic gas.
(b) Hydrogen chloride and chlorine gas.
(c) (i) Ammonium chloride
(ii) Ammonium nitrate
(iii) Ammonium carbonate
(d) Acidic gas: HCl
Basic gas: Ammonia
Neutral gas: NH4Cl
(e) Silver chloride
(g) Magnesium nitride
(h) Lead oxide
(i) Ammonium chloride
When ammonium hydroxide is added to solution B, a pale blue precipitate is formed. This pale blue precipitate dissolves in excess ammonium hydroxide giving an inky blue solution. What is the cation (positive ion) present in solution B? What is the probable colour of solution B.
CuSO4 + 2NH4OH(NH4)2SO4 +Cu(OH)2 [Pale blue]
The cation present in solution B is Copper (Cu+2).
The colour of solution B is Blue.
The pale blue precipitate of copper hydroxide dissolves in excess of ammonium hydroxide forming tetraamine copper[II] sulphate, an azure blue(deep blue) soluble complex salt.
Cu(OH)2 + (NH4)2SO4 +2NH4OH [Cu(NH3)4]SO4 + 4H2O
When an ammonium salt is warmed with sodium hydroxide solution, ammonia gas is evolved. State three ways in which you can identify this gas.
Three ways in which ammonia gas can be identified is:
It has a sharp characteristic odour
When a glass rod dipped in HCl is brought in contact with the gas white colour fumes of ammonium chloride are formed
It turns moist red litmus blue, moist turmeric paper brown and phenolphthalein solution pink.
A gas ‘A ‘reacts with another gas ‘B’ in the presence of a catalyst to give a colourless gas ‘C’. The gas ‘C’ when comes in contact with air produces a brown gas ‘D’. The solution of ‘A’ in water turns red litmus blue. Explain the observations.
As the ‘A’ turns red litmus blue it is a base.Now the gas ‘A’ combines with ‘B’ in presence of Catalyst to give colourless gas Nitrogen monoxide. It reacts with oxygen to give brown gas which is Nitrogen dioxide.
4NH3 + 5O2 4NO + 6H2O + Heat
2NO + O2 2NO2
NH3 in water forms NH4OH which turns red litmus blue.
(a) Name the common refrigerant .How does it deplete ozone layer?
(b) What is the alternative of chlorofluorocarbon?
(c) State the advantages and disadvanatages of using ammonia as refrigerant?
(a) The main refrigerants used are Freon chlorofluorocarbons (CFC). They deplete ozone layer. The chlorofluorocarbons are decomposed by ultraviolet rays to highly reactive chlorine which is produced in the atomic form.
The free radical [Cl] reacts with ozone and chlorine monoxide is formed.
This causes depletion of ozone layer and chlorine monoxide so formed reacts with atomic oxygen and produces more chlorine free radicals.
ClO + O Cl + O2
Again this free radical destroys ozone and the process continues thereby giving rise to ozone depletion.
(b) Liquid ammonia can be used as a refrigerant, as an alternative for chlorofluorocarbons.
(c) Advantages of ammonia as refrigerant:
(i) Ammonia is environmentally compatible. It does not deplete ozone layer and does not contribute towards global warming.
(ii) It has superior thermodynamic qualities as a result ammonia refrigeration systems use less electricity.
Ammonia has a recognizable odour and so leaks are not likely to escape.
Name a compound prepared by ammonia and is used as:
(d) Laboratory reagent
(a) Explosive: ammonium nitrate
(b) Medicine: ammonium carbonate
(c) Fertilizers: ammonium sulphate
(d) Laboratory reagent: ammonia solution
Write the equation for the action of heat on:
(a) Ammonium chloride
(b) Ammonium nitrate
State whether each reaction is an example of thermal decomposition or thermal dissociation.
(a) Ammonium chloride
NH4Cl NH3 +HCl
(b) Ammonium nitrate
NH4NO3 N2O +2H2O
Both are examples of Thermal dissociation.
(a) Which feature of ammonia molecule leads to the formation of the ammonium ion when ammonia dissolves in water?
(b) Name the other ion formed when ammonia dissolves in water.
(c) Give one test that can be used to detect the presence of the ion produced in (b).
(a) It is the basic nature of ammonia molecule.
(b) Hydroxyl ion (NH3 +H2O NH4+ + OH–)
(c) The red litmus paper turns blue in the solution.
(a) Of the two gases, ammonia and hydrogen chloride, which is more dense? Name the method of collection of this gas.
(b) Give one example of a reaction between the above two gases which produce a solid compound.
(c) Write the balanced equation for a reaction in which ammonia is oxidized by:
(i) A metal oxide
(ii) a gas which is not oxygen
(a) HCl gas is more dense [V.D.=18.25,V.D. of ammonia =8.5] and it is collected by the upward displacement of air.
(b) NH3 + HCl → NH4Cl
(c) Balanced equation:
(a) 2NH3 +3CuO 3Cu +3H2O +N2
(b) 2NH3 +3Cl2 N2 + 6HCl
Give reasons for the following:
(a) Liquid ammonia is used as a refrigerant in ice plants.
(b) Aqueous solution of ammonia is used for removing grease stains from woollen clothes.
(c) Aqueous solution of ammonia gives a pungent smell.
(d) Aqueous solution of ammonia conducts electricity.
(a) Liquid ammonia acts as a refrigerant in ice plants. Evaporation needs heat energy, and when liquid ammonia vaporises, it absorbs large quantities of heat without changing its temperature. For these reasons, ammonia is widely used as a refrigerant.
(b) Ammonia is used for removing grease and dirt as it emulsifies or dissolves them.
(c) Ammonia is formed by bacterial decomposition of urea, so ammonia has a pungent smell.
(d) An aqueous solution of ammonia is a weak electrolyte. It dissociates partially to give hydroxyl ions, and ions conduct electricity. So an aqueous solution of ammonia conducts electricity.
Previous Year Question of Exercise-9 ,Ammonia
(a) Write the equation for the following:Aluminium nitride and water
(b) Choose the correct option from the following: Ammonia can be obtained by adding water to
A : Ammonium chloride
B: Ammonium nitrite
C: Magnesium nitride
D: Magnesium nitrate
(b) C.: Magnesium nitride
(a) Name the gas evolved in each case [formula is not acceptable]. The gas that burns in oxygen with a green flame.
(b) Write a fully balanced equation for – Magnesium nitride is treated with warm water.
(c) Identify the substance ‘0’ based on the information given – The white crystalline solid ‘Q’ is soluble in water. It liberates a pungent smelling gas when heated with sodium hydroxide solution.
(c) ‘Q’ is ammonium chloride.
(a) Complete the blanks (i) to (v) in the passage given using the following words. [Ammonium, reddish brown, hydroxyl, nitrogen dioxide, ammonia, dirty green, alkaline, acidic]. In the presence of a catalyst, nitrogen and hydrogen combine to give (i) ………. gas. When the same gas is passed through water, it forms a solution which will be (ii) ………… in nature and will contain the ions (iii) ………… and (iv) ………… A (v) …………coloured precipitate of iron [H] hydroxide is formed when the above solution is added to iron [II] sulphate solution.
(b) State your observation when – In the absence of catalyst, ammonia is burnt in an atmosphere of oxygen.
(c) Give the equation for the reaction: Ammonium chloride is heated with sodium hydroxide.
(d) In the manufacture of ammonia,
(i) Name the process
(ii) State the ratio of the reactants
(iii) State the catalyst used
(iv) Give the equation for the manufacture of the gas – ammonia.
(e) Write a relevant equation to show that ammonia acts as a reducing agent.
(f) Name two gases which can be used to study the fountain experiment. State the common property demonstrated by the fountain experiment.
(v) Dirty green
(b) Ammonia burns with a yellowish flame. It produces water vapour and nitrogen.
(i) Haber’s process
(ii) 1 part of nitrogen gas and 3 parts of hydrogen gas
(iii) Finely divided iron (Fe)
(i) Ammonia and hydrogen chloride gas
(ii) High solubility of gases in water
(a) State what is observed when – Ammonium hydroxide is first added in a small quantity and then in excess to a solution of coppersulphate.
(b) The diagram below shows the setup for the laboratory preparation of a pungent alkaline gas.
(i) Name the gas collected in the jar.
(ii) Give a balanced equation for the above preparation.
(iii). State how the above gas is collected.
(iv) Name the drying agent used.
(v) State how you will find out that the jar is full of the pungent gas.
(c) Write a balanced chemical equation – Chlorine reacts with excess of ammonia.
(d) State your observation – Water is added to the product formed when Al is burnt in a jar of nitrogen gas.
(a) In small quantity: A bluish white ppt. is obtained.
In excess quantity: A deep blue solution is obtained.
(iii) By downward displacement of air
(v) Bring a moist red litmus paper to the mouth of the inverted jar if it immediately turns blue.
Bring a glass rod dipped in hydrochloric acid to the mouth of the inverted jar. If it produces dense white fumes, then the jar is full of gas.
(d) Pungent smelling basic gas called ammonia is evolved.
(a) Name – The gas produced when excess ammonia reacts with chlorine.
(b) Rewrite the correct statement with the missing word/s: Magnesium nitride reacts with water to liberate ammonia.
(c) Give a balanced equation for the reaction: Ammonia and oxygen in the presence of a catalyst.
(d) The following questions are based on the preparation of ammonia gas in the laboratory:
(i) Explain why ammonium nitrate is not used in the preparation of ammonia.
(ii) Name the compound normally used as a drying agent during the process.
(iii) How is ammonia gas collected? Explain why it is not collected over water.
(b) Magnesium nitride reacts with boiling water to liberate ammonia.
(i) Ammonium nitrate is a highly explosive substance and cannot be heated.
(iii) By the downward displacement of air or upward delivery as it is lighter than air.
It is not collected over water because it easily dissolves in water.
(a) State one appropriate observation for: Excess of chlorine gas is reacted with ammonia gas.
(b) Nitrogen gas can be obtained by heating
(i) Ammonium nitrate
(ii) Ammonium nitrite
(iii) Magnesium nitride
(iv) Ammonium chloride
(c) State two relevant observations for: Ammonium hydroxide solution is added to zinc nitrate solution slowly and then in excess.
(d) Give a balanced equation for: Reduction of hot copper (II) oxide to copper using ammonia gas.
(e) Copy and complete the following table relating to important industrial process:
|Name of the process||Temperature||Catalyst||Equation for the catalysed reaction|
(f) Identify: An alkaline gas which produces dense white fumes when reacted with HCl gas.
Answer 2013 Ammonia Selina Concise Solutions
(a) A yellow-coloured explosive is formed.
(b) Ammonium nitrite
(i) When added in small quantity, it forms a gelatinous white ppt.
(ii) When added in excess, it dissolves to form a complex salt.
|Name of the process||Temperature||Catalyst||Equation for the catalysed reaction|
|Haber’s process||450-500°C||Finely divided iron (Fe)|
Question 2014 Ammonia Selina Concise Solutions
(a) Fill in the blank from the choices given in brackets: Ammonia gas is collected by …………. [upward displacement of air, downward displacement of water downward displacement of air].
(b) Write a balanced equation for: Action of warm water on magnesium nitride.
(c) Distinguish between the following pairs of compounds using the test given in brackets:
(i) Iron[II] sulphate and iron[III] sulphate (using ammonium hydroxide)
(ii) A lead salt and a zinc salt (using excess ammonium hydroxide)
(d) State your observation: Calcium hydroxide is heated with ammonium chloride crystals.
(e) Name the other ion formed when ammonia dissolves in water. Give one test that can be used to detect the presence of the ion produced.
(f) State the conditions required for: Catalytic oxidation of ammonia to nitric oxide.
(a) Downward displacement of air.
(i) Iron(II) sulphate: Gives dirty green ppt. with ammonium hydroxide insoluble in excess.
(ii) Iron(III) sulphate: Gives reddish brown ppt. with ammonium hydroxide insoluble in excess.
(d) A colourless pungent-smelling ammonia gas is obtained.
(i) Hydroxyl (OH–) ion other than ammonium ion
(ii) Red litmus turns blue, methyl orange turns yellow and phenolphthalein turns pink.
(f) In the presence of platinum catalyst at 800°C.
(a) Give balanced chemical equations for
(i) Lab preparation of ammonia using ammonium salt
(ii) Reaction of ammonia with excess of chlorine
(iii) Reaction of ammonia with sulphuric acid
(b) From the list of gases – ammonia, ethane, hydrogen chloride, hydrogen sulphide, select the gas which is used as a reducing agent in reducing copper oxide to copper.
(i) 2NH4Cl + Ca (OH)2 → CaCl2 + 2H2O + 2NH3
(ii) NH3 + 3Cl2→ NCl3 + 3HCl
(iii) 2NH3 + H2SO4→ (NH4)2SO4
(b) Ammonia (NH3)
(a) Name the gas evolved when the following mixtures are heated are;
(i) Calcium hydroxide and Ammonium Chloride
(ii) Sodium Nitrite and Ammonium Chloride
(b) Write the balanced chemical equations for each of the following :
(i) When the excess of ammonia is treated with chlorine.
(ii) An equation to the illustrate the reducing nature of ammonia.
(i) 8NH3 + 3Cl2 → N2 + 6NH4Cl
(ii) 3PbO + 2NH3→3Pb + 3H2O + N2
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