Q: Question 3Give an example of a reaction where the following are involved:(a) Heat(b) Light(c) Electricity(d) Close contact(e) Solution(f) Pressure(g) Catalyst

(a) HeatCuCO3 (s) →Δ\xrightarrow{\Delta}Δ CuO (s) + CO2 ↑ (g)(b) Light2AgNO3 →sunlight\xrightarrow{\text{sunlight}}sunlight 2Ag + 2NO2 ↑ + O2 ↑(c) Electricity2NaCl →electricity\xrightarrow{\text{electricity}}electricity 2Na + Cl2 ↑(d) Close contactPb(NO3)2 (s) + 2KI (s) ⟶ 2KNO3 + PbI2 (s)(e) SolutionNaCl (aq.) + AgNO3 (aq.) ⟶ AgCl (white ppt.) ↓ + NaNO3 (aq.)(f) PressureN2 + 3H2 ⇌above 200 atm\xrightleftharpoons{\text{above 200 atm}}above 200 atm 2NH3 ↑(g) Catalyst2H2O2 →MnO2\xrightarrow{\text{MnO}_2}MnO2 2H2O + O2 ↑

Question 1

Question 3Give an example of a reaction where the following are involved:(a) Heat(b) Light(c) Electricity(d) Close contact(e) Solution(f) Pressure(g) Catalyst

Accepted Answer

(a) HeatCuCO3 (s) →Δ\xrightarrow{\Delta}Δ​ CuO (s) + CO2 ↑ (g)(b) Light2AgNO3 →sunlight\xrightarrow{	ext{sunlight}}sunlight​ 2Ag + 2NO2 ↑ + O2 ↑(c) Electricity2NaCl →electricity\xrightarrow{	ext{electricity}}electricity​ 2Na + Cl2 ↑(d) Close contactPb(NO3)2 (s) + 2KI (s) ⟶ 2KNO3 + PbI2 (s)(e) SolutionNaCl (aq.) + AgNO3 (aq.) ⟶ AgCl (white ppt.) ↓ + NaNO3 (aq.)(f) PressureN2 + 3H2 ⇌above 200 atm\xrightleftharpoons{	ext{above 200 atm}}above 200 atm​ 2NH3 ↑(g) Catalyst2H2O2 →MnO2\xrightarrow{	ext{MnO}_2}MnO2​​ 2H2O + O2 ↑

Question 2

Question 5Give an example of each of the following chemical changes.(a) A photochemical reaction involving 1. silver salt 2. water(b) A reaction involving 1. blue solution 2. formation of a dirty green precipitate(c) Two gases combine to form a white solid.(d) Two solids combine to form a liquid.(e) A reaction where color change is noticed.

Accepted Answer

(a) A photochemical reaction involving 1. silver salt2AgNO3 →sunlight\xrightarrow{	ext{sunlight}}sunlight​ 2Ag + 2NO2 ↑ + O2 ↑ 2. waterCl2 + H2O →sunlight\xrightarrow{	ext{sunlight}}sunlight​ HCl + HClO(b) A reaction involving 1. blue solutionFe iron+CuSO4 blue sol.⟶FeSO4 green sol.+Cu copper-brown red deposit\underset{	ext{ iron}}{	ext{Fe}} + \underset{	ext{ blue sol.}}{	ext{CuSO}_4} \longrightarrow \underset{	ext{ green sol.}}{	ext{FeSO}_4} + \underset{	ext{ copper-brown red deposit}}{	ext{Cu}} ironFe​+ blue sol.CuSO4​​⟶ green sol.FeSO4​​+ copper-brown red depositCu​2. formation of a dirty green precipitateFeSO4 ferrous sulphate+2NaOH sodium hydroxide⟶Fe(OH)2 dirty green ppt. ↓+Na2SO4 sodium sulphate\underset{	ext{ ferrous sulphate}}{	ext{FeSO}_4} + \underset{	ext{ sodium hydroxide}}{2	ext{NaOH}} \longrightarrow \underset{	ext{ dirty green ppt. }}{	ext{Fe(OH)}_2}↓ + \underset{	ext{ sodium sulphate}}{	ext{Na}_2	ext{SO}_4} ferrous sulphateFeSO4​​+ sodium hydroxide2NaOH​⟶ dirty green ppt. Fe(OH)2​​↓+ sodium sulphateNa2​SO4​​(c) Two gases combine to form a white solid.NH3 (g) + HCl (g) ⟶ NH4Cl (s)(d) Two solids combine to form a liquid.C (s) + 2S (s) ⟶ CS2 (l)(e) A reaction where color change is noticed.Fe iron+CuSO4 blue sol. (aq.)⟶FeSO4 green sol.+Cu copper-brown red deposit\underset{	ext{ iron}}{	ext{Fe}} + \underset{	ext{ blue sol.}}{	ext{CuSO}_4} 	ext{ (aq.)} \longrightarrow \underset{	ext{ green sol.}}{	ext{FeSO}_4} + \underset{	ext{ copper-brown red deposit}}{	ext{Cu}} ironFe​+ blue sol.CuSO4​​ (aq.)⟶ green sol.FeSO4​​+ copper-brown red depositCu​

Question 3

Question 6Write the chemical reaction where the following changes are observed.(a) Gas is evolved(b) Colour change is noticed(c) Precipitate is formed(d) Physical state of reactants is changed

Accepted Answer

(a) Gas is evolvedZn(s) + H2SO4 (aq) ⟶ ZnSO4 (aq) + H2 (g)(b) Colour change is noticedFe iron+CuSO4 blue sol. (aq.)⟶FeSO4 green sol.+Cu copper-brown red deposit\underset{	ext{ iron}}{	ext{Fe}} + \underset{	ext{ blue sol.}}{	ext{CuSO}_4} 	ext{ (aq.)} \longrightarrow \underset{	ext{ green sol.}}{	ext{FeSO}_4} + \underset{	ext{ copper-brown red deposit}}{	ext{Cu}} ironFe​+ blue sol.CuSO4​​ (aq.)⟶ green sol.FeSO4​​+ copper-brown red depositCu​(c) Precipitate is formedFeSO4 (aq.) ferrous sulphate+2NaOH (aq.) sodium hydroxide⟶Fe(OH)2↓ dirty green ppt.+Na2SO4 (aq.) sodium sulphate\underset{	ext{ ferrous sulphate}}{	ext{FeSO}_4 	ext{ (aq.)}} + \underset{	ext{ sodium hydroxide}}{2	ext{NaOH}	ext{ (aq.)}} \longrightarrow \underset{	ext{ dirty green ppt.}}{	ext{Fe(OH)}_2↓} + \underset{	ext{ sodium sulphate}}{	ext{Na}_2	ext{SO}_4	ext{ (aq.)}} ferrous sulphateFeSO4​ (aq.)​+ sodium hydroxide2NaOH (aq.)​⟶ dirty green ppt.Fe(OH)2​↓​+ sodium sulphateNa2​SO4​ (aq.)​(d) Physical state of reactants is changedC (s) + 2S (s) ⟶ CS2 (l)

Question 4

Question 7Give reason for the following :(a) Silver nitrate solution is kept in coloured bottles.(b) Molybdenum is used in the manufacture of ammonia.(c) Blue solution of copper sulphate changes to green when a piece of iron is added to this solution.(d) Colourless concentrated sulphuric acid in a test tube changes to blue on adding a small piece of copper to it.

Accepted Answer

(a) Silver nitrate solution is kept in brown bottles in the laboratory because it decomposes in the presence of light. It becomes black and forms silver, nitrogen dioxide and oxygen.2AgNO3 →sunlight\xrightarrow{	ext{sunlight}}sunlight​ 2Ag + 2NO2 ↑ + O2 ↑(b) Molybdenum acts as a promoter and increases the efficiency of the catalyst iron, hence it is used in the manufacture of ammonia.(c) When a piece of iron is added to a blue coloured copper sulphate solution, the blue colour of the solution fades and eventually turns into light green due to the formation of ferrous sulphate.Fe iron+CuSO4 blue sol. (aq.)⟶FeSO4 green sol.+Cu copper-brown red deposit\underset{	ext{ iron}}{	ext{Fe}} + \underset{	ext{ blue sol.}}{	ext{CuSO}_4}	ext{ (aq.)} \longrightarrow \underset{	ext{ green sol.}}{	ext{FeSO}_4} + \underset{	ext{ copper-brown red deposit}}{	ext{Cu}} ironFe​+ blue sol.CuSO4​​ (aq.)⟶ green sol.FeSO4​​+ copper-brown red depositCu​(d) When a small piece of copper is added to concentrated sulphuric acid, a blue solution of copper sulphate is formed.Cu (s) brown+2H2SO4(aq) conc.⟶CuSO4(aq) blue+2H2O (l)+SO2(g)\underset{	ext{ brown}}{	ext{Cu (s)}} + \underset{	ext{ conc.}}{2	ext{H}_2	ext{SO}_4	ext{(aq)}} \longrightarrow \underset{	ext{ blue}}{	ext{CuSO}_4	ext{(aq)}} + 2	ext{H}_2	ext{O (l)} + 	ext{SO}_2	ext{(g)} brownCu (s)​+ conc.2H2​SO4​(aq)​⟶ blueCuSO4​(aq)​+2H2​O (l)+SO2​(g)

Question 5

Question 5Explain the following chemical changes by giving one example of each:(a) Double decomposition(b) Thermal dissociation(c) Reversible reaction(d) Displacement

Accepted Answer

(a) Double decomposition — This is a type of chemical change in which two compounds in a solution react to form two new compounds by mutual exchange of radicals. Double decomposition reaction is also called double displacement reaction.AB + CD ⟶ AD + CBEg., AgNO3 + NaCl ⟶ AgCl ↓ + NaNO3(b) Thermal dissociation — A reversible decomposition reaction brought about only by heat is called thermal dissociation reaction.Heat some solid ammonium chloride in a test tube. Two colourless gases, ammonia and hydrogen chloride, are produced. As these gases move up to the upper part of the test tube which is cooler, they combine to form ammonium chloride, which appears as a white sublimate on the upper cooler side of the test tube.NH4Cl ⇌ NH3 ↑ + HCl ↑(c) Reversible reaction — A reaction that can be reversed by changing the conditions under which the reaction is taking place is called a reversible reaction.3Fe red hot iron+4H2O steam⇌Fe3O4 magnetic oxide+4H2 hydrogen gas\underset{	ext{ red hot iron}}{	ext{3Fe}} + \underset{	ext{ steam}}{4	ext{H}_2	ext{O}} ightleftharpoons \underset{	ext{ magnetic oxide}}{	ext{Fe}_3	ext{O}_4} + \underset{	ext{ hydrogen gas}}{4	ext{H}_2} red hot iron3Fe​+ steam4H2​O​⇌ magnetic oxideFe3​O4​​+ hydrogen gas4H2​​(d) Displacement — A chemical change in which a more active element displaces a less active element from its salt solution is called a displacement reaction.Mg + H2SO4 ⟶ MgSO4 + H2 ↑

Question 6

Question 6(a) What is synthesis?(b) What kind of chemical reaction is synthesis? Support your answer with an example.

Accepted Answer

(a) A reaction in which two or more substances combine together to form a single substance is called a synthesis or combination reaction.A + B ⟶ AB(b) Synthesis is a direct combination reaction.In the above reaction, substances A and B combine to give a molecule of a new substance, AB (Product).For example, carbon burns in oxygen to form a gaseous compound, carbon dioxide.C + O2 →Δ\xrightarrow{\Delta}Δ​ CO2 ↑

Question 7

Question 9What do you understand by precipitation reaction? Explain with an example.

Accepted Answer

A chemical reaction in which two compounds in their aqueous state react to form an insoluble salt (precipitate) as one of the products is called a precipitation reaction.Example: Take a solution of silver nitrate in a test tube and add dil. hydrochloric acid. A curdy white ppt. is formed.AgNO3 + HCl ⟶ AgCl ↓ + HNO3

Question 8

Question 11(a) What is a decomposition reaction ?(b) Decomposition reactions can occur by (i) heat (ii) electricity and (iii) sunlight.Give two balanced reactions for each.

Accepted Answer

(a) The chemical reaction in which a compound splits into two or simpler substances (elements or compounds) is called decomposition reaction.(b) Two balanced chemical equations for:(i) Heat2HgO (s) →Δ\xrightarrow{\Delta}Δ​ 2Hg (l) + O2 (g)CaCO3 (s) →Δ\xrightarrow{\Delta}Δ​ CaO (s) + CO2 (g)(ii) Electricity2NaCl (l) →electricity\xrightarrow{	ext{electricity}}electricity​ 2Na (l) + Cl2 (g)2H2O (l) →electricity\xrightarrow{	ext{electricity}}electricity​ 2H2 (g) + O2 (g)(iii) Light2AgCl (s) → sunlight\xrightarrow{	ext{ sunlight}} sunlight​ 2Ag (s) + Cl2 (g)2H2O2 (l) → sunlight\xrightarrow{	ext{ sunlight}} sunlight​ 2H2O (l) + O2 (g)

Question 9

Question 12State the type of reactions each of the following represent and balance the ones that are not balanced.(a) Cl2 + 2KBr ⟶ 2KCl + Br2(b) NaOH + HCl ⟶ NaCl + H2O(c) 2HgO ⟶ 2Hg + O2 ↑(d) Fe + CuSO4 ⟶ FeSO4 + Cu(e) PbO2 + SO2 ⟶ PbSO4(f) 2KClO3 ⟶ 2KCl + 3O2 ↑(g) 2H2O2 ⟶ 2H2O + O2 ↑(h) KNO3 + H2SO4 ⟶ HNO3 + KHSO4(i) CuO + H2 ⟶ Cu + H2O(j) CaCO3 ⟶ CaO + CO2 ↑(k) NH4Cl ⟶ NH3 + HCl(l) PbO + 2HNO3 ⟶ Pb(NO3)2 + 2H2O(m) AgNO3 + NaCl ⟶ AgCl ↓ + NaNO3

Accepted Answer

(a) Cl2 + 2KBr ⟶ 2KCl + Br2Displacement reaction(b) NaOH + HCl ⟶ NaCl + H2ONeutralisation reaction(c) 2HgO ⟶ 2Hg + O2 ↑Decomposition reaction(d) Fe + CuSO4 ⟶ FeSO4 + CuDisplacement reaction(e) PbO2 + SO2 ⟶ PbSO4Combination reaction(f) 2KClO3 ⟶ 2KCl + 3O2 ↑Decomposition reaction(g) 2H2O2 ⟶ 2H2O + O2 ↑Decomposition reaction(h) KNO3 + H2SO4 ⟶ HNO3 + KHSO4Double decomposition reaction(i) CuO + H2 ⟶ Cu + H2ODisplacement reaction(j) CaCO3 ⟶ CaO + CO2 ↑Decomposition reaction(k) NH4Cl ⟶ NH3 ↑ + HClDecomposition reaction(l) PbO + 2HNO3 ⟶ Pb(NO3)2 + H2ONeutralisation reaction(m) AgNO3 + NaCl ⟶ AgCl ↓ + NaNO3Double decomposition reaction

Question 10

Question 4What do you observe in the following cases?(a) Lead nitrate is heated.(b) Silver chloride is exposed to sunlight.(c) Hydrogen peroxide is exposed to sunlight(d) H2S gas is passed through copper sulphate solution(e) Barium chloride is added to sodium sulphate solution.(f) Water is added to quick lime(g) Sodium chloride solution is added to silver nitrate solution.

Accepted Answer

(a) When white crystalline solid Lead nitrate is heated, it decomposes into a buff yellow residue of lead monoxide. Reddish brown gas Nitrogen dioxide and colourless gas Oxygen are evolved.2Pb(NO3)2[lead nitrate (white)]⟶Δ2PbO[litharge - buff yellow]+4NO2[Nitrogen dioxide]+O2[Oxygen]\underset{	ext{[lead nitrate (white)]}}{2	ext{Pb(NO}_3)_2} \overset{\Delta}{\longrightarrow} \underset{	ext{[litharge - buff yellow]}}{2	ext{PbO}} + \underset{	ext{[Nitrogen dioxide]}}{4	ext{NO}_2} + \underset{	ext{[Oxygen]}}{	ext{O}_2}[lead nitrate (white)]2Pb(NO3​)2​​⟶Δ​[litharge - buff yellow]2PbO​+[Nitrogen dioxide]4NO2​​+[Oxygen]O2​​(b) When silver chloride (white) is exposed to sunlight, it undergoes photochemical decomposition forming a grey metal, silver and a greenish yellow gas, chlorine.2AgCl (s) → sunlight\xrightarrow{	ext{ sunlight}} sunlight​ 2Ag (s) + Cl2 (g)(c) When hydrogen peroxide is exposed to sunlight, it changes to water and colourless, odourless oxygen gas is evolved.2H2O2 → sunlight\xrightarrow{	ext{ sunlight}} sunlight​ 2H2O + O2 ↑(d) When H2S is passed through copper sulphate solution, a black precipitate of copper sulphide is obtainedCuSO4 + H2S ⟶ CuS [black] + H2SO4(e) White coloured precipitate of barium sulphate is formed when sodium sulphate is mixed with barium chloride.Na2SO4 (aq.) + BaCl2 (aq.) ⟶ 2NaCl (aq.) + BaSO4 [white ppt.] ↓(f) When calcium oxide (quick lime) combines with water, a vigorous reaction takes place with the liberation of a large amount of heat (exothermic reaction) and calcium hydroxide is formed. Heat produced boils the water and a hissing sound is produced.CaO (s) + H2O (l) ⟶ Ca(OH)2 (s) + Heat(g) When sodium chloride is added to the silver nitrate solution, a white curdy precipitate of silver chloride is formed.NaCl (aq.) + AgNO3 (aq.) ⟶ AgCl (white ppt.) ↓ + NaNO3 (aq.)

Question 11

Question 11Discuss some decomposition reactions occurring inside our body.

Accepted Answer

Digestion of food in our body is an example of decomposition reaction.The starch present in the food we eat decomposes into glucose and sugar. Proteins undergo decomposition to form amino acids. Fats and oils are decomposed to fatty acids and finally oxidized by respiration into carbon dioxide and water.Starch →Enzymes\xrightarrow{	ext{Enzymes}}Enzymes​ Glucose →[O]\xrightarrow{	ext{[O]}}[O]​ CO2 + H2O + Energy

Question 12

Question 1(ii)Heating of zinc nitrate is a ............... reaction.DisplacementCombinationDecompositionRedox

Accepted Answer

Decomposition reactionReason — Zinc nitrate undergoes thermal decomposition and produces reddish brown Nitrogen dioxide gas (NO2), Zinc oxide (ZnO), and Oxygen gas (O2).Zn(NO3)2→Δ4NO2+2ZnO+O2↑	ext{Zn}(	ext{NO}_3)_2 \xrightarrow{\Delta} 	ext{4NO}_2 + 	ext{2ZnO} + 	ext{O}_2 ↑Zn(NO3​)2​Δ​4NO2​+2ZnO+O2​↑

Question 13

Question 1(x)Aman performed the following four experimentsThe experiments in which the blue colour of the solution will fade are :P and QP, Q and RQ and RQ, R and S

Accepted Answer

Q and RReason — Blue colour is because of CuSO4. In experiment Q, zinc displaces copper from copper sulphate solution because zinc is more reactive and present above copper in reactivity series.CuSO4 (aq) + Zn ⟶ ZnSO4 + Cu ↓In experiment R, iron displaces copper from copper sulphate solution because iron is also more reactive and present above copper in reactivity series.Fe iron+CuSO4 blue sol. (aq.)⟶FeSO4 green sol.+Cu copper-brown red deposit\underset{	ext{ iron}}{	ext{Fe}} + \underset{	ext{ blue sol.}}{	ext{CuSO}_4}	ext{ (aq.)} \longrightarrow \underset{	ext{ green sol.}}{	ext{FeSO}_4} + \underset{	ext{ copper-brown red deposit}}{	ext{Cu}} ironFe​+ blue sol.CuSO4​​ (aq.)⟶ green sol.FeSO4​​+ copper-brown red depositCu​Hence, in experiment Q and R, copper is displaced by more reactive metal. So, the blue colour of the solution will fade.

Question 14

Question 2(i)Assertion (A): Zinc can displace copper from aqueous copper sulphate solution.Reason (R): Copper is placed above zinc in the reactivity series.Both A and R are true and R is the correct explanation of A.Both A and R are true but R is not the correct explanation of A.A is true but R is false.A is false but R is true.

Accepted Answer

A is true but R is false.Explanation — Zinc is more reactive than copper. So, zinc is placed above copper in reactivity series. Hence, zinc displaces copper from aqueous copper sulphate solution. Hence the assertion (A) is true.CuSO4 (aq) + Zn → ZnSO4 + Cu ↓Copper is less reactive than zinc and is placed below zinc in reactivity series. Less reactive elements cannot displace more active elements. Hence, copper cannot displace zinc from its salt solution. Hence the reason (R) is false.

Question 15

Question 2(iv)Assertion (A): The decomposition of silver bromide is utilized in black and white photography.Reason (R): Light provides energy for this endothermic reaction.Both A and R are true and R is the correct explanation of A.Both A and R are true but R is not the correct explanation of A.A is true but R is false.A is false but R is true.

Accepted Answer

Both A and R are true and R is the correct explanation of A.Explanation — Silver bromide (AgBr) decomposes when exposed to light. The formation of black metallic silver is what creates the image in black and white photography. Hence the assertion (A) is true.2AgBr →light\xrightarrow{	ext{light}}light​ 2Ag + BrAbove reaction is an endothermic reaction where heat is absorbed. Light provides energy for this decomposition of silver bromide. Hence the reason (R) is true and reason (R) is a correct explanation of assertion (A).

Question 16

Question 2(v)Assertion (A): Chlorine can displace iodide ions from KI solution.Reason (R): It is an example of displacement reaction.Both A and R are true and R is the correct explanation of A.Both A and R are true but R is not the correct explanation of A.A is true but R is false.A is false but R is true.

Accepted Answer

Both A and R are true but R is not the correct explanation of A.Explanation — Chlorine is more active non-metal when compared to iodine. In the reactivity series of non-metals, chlorine is placed above iodine. Hence, chlorine displaces iodine from potassium iodide solution. Hence, the assertion (A) is true.2KI + Cl2 ⟶ 2KCI + I2Above reaction is displacement reaction in which a more active element chlorine displaces a less active element iodine from its salt solution. Hence the reason (R) is true.However reason (R) does not explain about reactivity of chlorine and position of chlorine and iodine in reactivity series. Hence reason (R) is not a correct explanation of assertion (A).

Question 17

Question 2(vi)Assertion (A): Silver is displaced by copper from the aqueous solution of silver nitrate.Reason (R): Copper is placed below silver in the activity series.Both A and R are true and R is the correct explanation of A.Both A and R are true but R is not the correct explanation of A.A is true but R is false.A is false but R is true.

Accepted Answer

A is true but R is false.Explanation — Silver is displaced by copper from the aqueous solution of silver nitrate because copper is more reactive than silver. Hence the assertion is true.Copper is placed above silver in the activity series. So copper is more reactive and can displace silver. Hence the reason (R) is false.

Question 18

Question 1K, Na, Ca, Mg, Al, Zn, Fe, Pb, Cu, H, Hg, AgPick an element from the reactivity series given above and write the equations for the the following:(a) Metal hydroxide on heating forms metal oxide and water vapour.(b)	Metal hydroxide on heating forms metal, oxygen and water vapours.(c)	Metal nitrate decomposes to give two products only.(d) Metal nitrate on heating forms metal oxide, nitrogen dioxide and oxygen.(e) Metal nitrate on heating forms metal, nitrogen dioxide and oxygen.(f) Metal carbonate which is stable to heat.(g)	Metal carbonate which forms metal oxide and carbon dioxide on heating.(h)	The heating effect on bivalent metal hydrogen carbonate.

Accepted Answer

(a) Metal hydroxide on heating forms metal oxide and water vapour — Calcium hydroxideCa(OH)2 →Δ\xrightarrow{\Delta}Δ​ CaO + H2O(b)	Metal hydroxide on heating forms metal, oxygen and water vapours — silver hydroxide4AgOH →Δ\xrightarrow{\Delta}Δ​ 4Ag + O2 + 2H2O(c)	Metal nitrate decomposes to give two products only — potassium nitrate2KNO3 →Δ\xrightarrow{\Delta}Δ​ 2KNO2 + O2 ↑(d) Metal nitrate on heating forms metal oxide, nitrogen dioxide and oxygen — Lead nitrate2Pb(NO3)2 →Δ\xrightarrow{\Delta}Δ​ 2PbO + 4NO2 + O2 ↑(e) Metal nitrate on heating forms metal, nitrogen dioxide and oxygen — Silver nitrate2AgNO3 →Δ\xrightarrow{\Delta}Δ​ 2Ag + 2NO2 + O2 ↑(f) Metal carbonate which is stable to heat — Potassium carbonatePotassium carbonate is stable to heat(g)	Metal carbonate which forms metal oxide and carbon dioxide on heating — Magnesium carbonateMgCO3 →Δ\xrightarrow{\Delta}Δ​ MgO + CO2 ↑(h)	The heating effect on bivalent metal hydrogen carbonate — Magnesium bicarbonateMg(HCO3)2 →Δ\xrightarrow{\Delta}Δ​ MgCO3 + H2O + CO2 ↑

Chemical Changes and Reactions

Exercise 2A

Exercise 2B

Exercise 2C Descriptive Type

Exercise 2C Multiple Choice Type

Exercise 2C Structuresapplicationskill Type