(b) Lithium cannot be used in making photoelectric cells. (c) Na2O and CO2 On the other hand, in lithium chloride (LiCl) the lattice enthalpy is comparatively very small. Halogen rule 1. Explain why is sodium less reactive than potassium. Alkali metal salts are not soluble while nitrate salts are soluble… Why is Li2CO3 decomposed at a lower temperature whereas Na2CO3 at higher temperature? (a) sodium (b) silicon (c) nitrogen (d)magnesium Nitrates. Most hydroxide (OH¯) salts are insoluble. 1. The exceptions are the alkali metal hydroxides and Ba(OH) 2. osti.gov journal article: solubility in ternary water-salt systems containing cerium nitrates and alkali metal nitrates Why are alkali metals always univalent? Answer: Let x be the oxidation state of Na in Na2O2     2x + 2 (-1) = 0  2x – 2 = 0    2x = 2 x = +1. Some Li + are insoluble, with Li 3 PO 4 being the most common example. Data on some, such as cesium and rubidium fluoride, nitrate, carbonate, and sulfate, appear to be reported for the first time. 2M(NO 3) … (a) Alkali metals show only +1 oxidation state. These rules are general and qualitative in nature. What happens when (i) magnesium is burnt in air, (ii) Quick lime is heated with silica (iii) chlorine reacts with slaked lime (iv) calcium nitrate is heated? LiF is soluble in non-polar solvents like kerosene. When alkali metal dissolves in liquid ammonia, the solution can acquire different colours. Alkali metals impart characteristic colours to the flame. In the vapour state, it exists as a chlorobridged dimer. (ii) Basicity of oxides. 3. Answer:  Be and Mg. State as to why The oxide of which of the following metals is amphoteric? (b) Lattice enthalpy of LiF is maximum among all the alkali metal halides. All nitrates are soluble, even if it’s a lead nitrate. Potassium carbonate cannot be prepared by Solvay process. They have a strong tendency to lose 1 electron to form unipositive ions. Question 31. CaO + CO 2 ↑ The thermal stability of carbonates of alkaline earth metals increase down the group. In the Solvay process Solubilities of the halides, nitrates, carbonates, sulfates, and some perchlorates of all the alkali metals and alkaline earth metals in methanol at room temperature have been determined. Alkali metals are highly reactive in nature. Question 2. . 2. Na + H2O —–> NaOH + 1/2H2 Lead and Silver rule 1. Answer: The low solubility of LiF in water is due to its very high lattice enthalpy (F–  ion is very small in size). ‘ … Which of the following is the least thermally stable? Nitrates , carbonates and sulphates of Alkali metals are soluble in water . Answer: Alkali metals dissolve in liquid ammonia and give deep blue solutions which are conducting in nature because ammoniated electrons absorb energy in the visible region of light and impart blue colour. All nitrate (NO 3 ¯), nitrite (NO 2 ¯), chlorate (ClO 3 ¯) and perchlorate (ClO 4 ¯) salts are soluble. (a) and (d) 7. What happens when it is added to water? The most important slightly soluble substance is calcium hydroxide, Ca(OH)2. a) Alkali metal salts are soluble and nitrate salts are not. Most nitrates tend to decompose on heating to the metal oxide, brown fumes of nitrogen dioxide, and oxygen. (2) All acetate, perchlorate, chlorate, and nitrate compounds are soluble. Question 11. What is Quick lime? Question 7. Therefore lithium chloride dissolves in water. (i) caustic soda (ii) sodium carbonate (iii) quick lime Which electrolyte is used to obtain sodium in Castner’s process? Explain the significance of sodium, potassium, magnesium and calcium in biological fluids. Question 18. 2M(NO 3) 2 → 2MO + 4 NO 2 + O 2. At cathode: (c) Lithium does not form alums. (b) When is a cation highly polarising? Silver nitrite and potassium perchlorate are considered slightly soluble. Therefore, the hydroxides and carbonates of these metals are only sparingly soluble in water. 2. Question 9. Topics and Subtopics in NCERT Solutions for Class 11 Chemistry Chapter 10 The s-Block Elements: NCERT Solutions Class 11 ChemistryChemistry Lab ManualChemistry Sample Papers. Why are alkali metals not found in nature? Discuss the general characteristics and gradation in properties of alkaline earth metals. (i) Chile salt petre (ii) Marble (iii) Brine Answer: Question 3. Halides Nitrate and Alkali Metal rule o 2. Answer: NaOH is more basic. In case of sodium and potassium compounds, the magnitude of lattice enthalpy is quite small as compared of sodium and potassium that are mentioned, readily dissolve in water. Give the important uses of the following compounds. Alkaline earth metal carbonates and sulphates have lower solubility than alkali metal carbonates and sulphates. This brings up an important part of the solubility rules: their order. On heating, Beryllium nitrate forms nitrite and, other nitrates yield oxide, liberating brown fumes of nitrogen dioxide. Answer: Question 8. Answer: Size of Cs is the biggest thus, its melting point is the lowest, (d) is correct. Alkali metals have low ionization enthalpies. (a) Therefore, a large amount of energy is needed to excite their valence electron, and that’s why they do not impart colour to the flame. It is mild antiseptic for skin infections. (a) Nitrates (b) Carbonates (c) Sulphates Answer: (a) Nitrates of both group 1 and group 2 elements are soluble in water because hydration energy is more than the lattice energy. Nitrates. You can disable footer widget area in theme options - footer options, NCERT Solutions for Class 11 Chemistry Chapter 10 The s-Block Elements, NCERT Class 11 Chemistry Textbook Solved Questions, NCERT Solutions for Class 11 Chemistry Chapter 10 Very Short Answer Type Questions, NCERT Solutions for Class 11 Chemistry Chapter 10 Short Answer Type Questions, Question 1. Arrange the following in the increasing order of solubility in water. Thus it undergoes hydrolysis to produce strong base NaOH and its aqueous solution is alkaline in nature. For example, a typical Group 2 nitrate like magnesium nitrate decomposes like this: In Group 1, lithium nitrate behaves in the same way - producing lithium oxide, nitrogen dioxide and oxygen. Part 2. Answer: Potassium carbonate being more soluble than sodium bicarbonate does not get precipitated when CO2 is passed through a concentrated solution of KCl saturated with ammonia. Which alkali metal ion forms largest hydrated ion in aqueous solution? Why? 2Cl– (melt) ——-> Cl2 (g) + 2e–. (iii) Solubility of hydroxides of alkali metals are higher than that of alkaline earth metals. (d) 5. (c) Due to small size, lithium does not form alums. This substance does not exist; it cannot be isolated as a pure substance. 1. Nitrate and Alkali Metal rule 2. Why are ionic hydrides of only alkali metals and alkaline earth metals are known? Solubility. (i) NaHCO3 (ii) NaOH Down the group thermal stability of nitrates increases. Extensively used in the manufacturing of high quality paper. Question 30. (c)Due to the small size of Li+ it has a strong positive field which attracts the negative charge so strongly that it does not permit the oxide ion, 02- to combine with another oxygen atom to form peroxide ion. (a) 2. Answer: (a) The unusual properties of lithium as compared to other alkali metals is due to its exceptionally small size of atom and its ion and its high polarising power. (c) Sulphates of group 1 are soluble in water except Li2SO4. Na + C2H5OH ——–> C2H5ONa + ½ H2. Since Ionization enthalpy of potassium is less than that of sodium, potassium is more reactive than sodium. Nitrates of alkaline and alkali metals give corresponding nitrites except for lithium nitrate, it gives lithium oxides. 2Cl-(aq) – 2e- ———> Cl2(g). 1. When ammonia gas (NH3) is bubbled through water, it dissolves and a small number of ammonia molecules react with the water to produce NH4+ and OH¯ ions. Alkali metals hydroxides are highly basic in nature. Answer: (a) Na2O2 + 2H2O ——-> 2Na0H + H2O2 Give two examples. 3. Alkali metals dissolve in liquid ammonia to form blue and conducting solution. Thermal stability. Alkali metals due to lower ionization enthalpy are more electropositive than the corresponding group 2 elements. Answer: Benzene can be used to store an alkali metal because other substances react with alkali metal as: The Solubility Rules. SOLUBILITY RULES A SUMMARY OF SOLUBILITIES RULE EXCEPTIONS 1. (a) Na < K < Rb < Cs < Li (b) K < Na < Rb < Cs < Li . Explain why can alkali and alkaline earth metals not be obtained by chemical reduction method. 1. 2. Question 14. Na (am) + e- (am) + NH3(l) ——–> NaNH2(am) + —1/2 H2(g). Solubilities of the halides, nitrates, carbonates, sulfates, and some perchlorates of all the alkali metals and alkaline earth metals in methanol at room temperature have been determined. The solubility data at 1 bar or saturation pressure for sodium nitrate are reviewed. What happens when Why are potassium and caesium, rather than lithium used in photoelectric cells? Answer:  Because alkali and alkaline earth metals are themselves stronger reducing agents than the majority of other reducing agents. This website has definitions for soluble, insoluble and slightly soluble plus a good set of rules for solubility at the end of the file. Group 2 carbonates are insoluble in water because their Lattice energy are higher than hydration energy. Which alkaline earth metals do not impart colour to the flame? Thus Lil dissolves in ethanol more easily than the KI. Why is BeCl2 soluble in organic solvent? It is also soluble in acetone due to dipolar attraction. Question 28.Write balanced equations for reactions between. Nitrates (NO 3-), chlorates (ClO 3-), and perchlorates (ClO 4-) are soluble. Answer: (a) Nitrates of both group 1 and group 2 elements are soluble in water because hydration energy is more than the lattice energy. At cathode: Answer:  Beryllium does not impart colour to a non-luminous flame. (b) 2KO2 + 2H2O ———-> 2K0H + O2+ H2O2 Save my name, email, and website in this browser for the next time I comment. Answer: Alkali metals and alkaline earth metals are most electropositive due to low ionization ethalpy therefore they form ionic hydrides, e.g. (a) KO2(b) CrO5(c) Na2O2 (d) BaO2 Question 9. Question 10. Both the elements have the tendency to form covalent compounds. (c) Na2O+ CO2 ———–>Na2CO3. LiCl is soluble in water because its hydration energy is higher than its lattice energy. Nitrate and Alkali Metal rule 3. Question 2. For example, a typical Group 2 nitrate like magnesium nitrate decomposes this way: (1) 2 M g (N O 3) 2 (s) → 2 M g O (s) + 4 N O 2 (g) + O 2 (g) Sulphates of group 2 elements are thermally stable and increasing down the group due to increases in Lattice energy. Answer: (a) Na2CO3 is a salt of a weak acid, carbonic acid (H2CO3) and a strong base NaOH. Question 9. (a) an ammoniacal brine solution is carbonated with CO2, forming NaHCO3 which on decomposition at 150°C produces Na2CO3 Therefore, it is almost insoluble in water. Li+ ion has the highest polarising power. Give the chemical equation also. Question 10. (d) 3. Other solubility tables can be seen via this solubility table search. (b) alkali metals are prepared by electrolysis of their fused chlorides? Question 20. Question 5. (a) Used in the softening of water, for laundry and cleaning purposes. Question 1. Therefore alkali metals are prepared by electrolysis of their fused chlorides. 2Na + O2 ——-> Na2O2. Answer: All the compounds are crystalline solids and their solubility in water is guided by both lattice enthalpy and hydration enthalpy. Answer: (d) BaCO3. Question 9. Answer:  (a) Alkali metals have low ionization enthalpies. Silver acetate, mercurous acetate, and lead acetate are moderately soluble. Where appropriate, binary, ternary, and multicomponent systems are critically evaluated. Question 1. (c) MgCl2 is electrolysed. (c) Ee for M2+ (aq) + 2e– —> M(s) (where M = Ca, Sr, or Ba) is nearly constant. In the transport of sugars and amino acids into cell. Question 2. From Li to Cs, thermal stability of carbonates increases. Trump suggests he may not sign $900B stimulus bill. Ammonium (NH 4 +) compounds are soluble. Question 1. 4. Answer: Due to smallest size, Li+ can polarize water molecules easily than the other alkali metal ions. Na+ + e– —–> Na Lithium when heated with ammonia forms lithium imide while other alkali metals form amides of the general formula ( where M=Na,K, Rb and S). Question 6. From Li to Cs, due to larger ion size, hydration enthalpy decreases. (b) It is used in textile industries. Hydrides as well as halides of alkaline earth metals tend to polymerize Question 7. Why does the solution of alkali metals becomes blue in liquid ammonia? (a) Nitrates-Alkali and alkaline earth metal nitrates are soluble in water. H2O, C2H5OH and Benzene 3. Question 13. Volume 89: Jitka Eysseltová and Violetta Timofeevna Orlova Alkali Metal Nitrates (two parts) IUPAC Project Part 1. Solubility of sulphates of group 2 decreases down the group because Lattice energy dominates over hydration energy. (a) MgCO3 (b) CaCO3 (c) SrCO3 (d) BaCO3 Participate in the oxidation of glucose to produce ATP. (a) Nitrates (b) Carbonates (c) Sulphates Answer: (a) Nitrates of both group 1 and group 2 elements are soluble in water because hydration energy is more than the lattice energy. Nitrates are soluble in water. Silver and lead ion are mostly soluble, except when paired with nitrate, acetate and… Question 16. Indeed, I found one website with four terms. Question 10. Question 3. Na+ + e– —–> Na (l) Question 3. Question 11. Answer: (i) 2Na + 2H2O ——–> 2NaOH + H2 What happens when sodium metal is heated in free supply of air? (c) Sodium is found to be move useful than potassium? (a) Why Cs is considered as the most electropositive element? Whereas  BeSO4 is ionic in nature and its hydration energy dominates the lattice energy. Which of the following is not a peroxide? Comment on each of the following observations: Cl + Cl——–>Cl2 Why alkali and alkaline earth metals cannot be obtained by chemical reduction method? Answer: Since BeCl2 is a covalent compound it is soluble in organic solvent. Question 4. Their resultant is almost constant for these ions. MgO is basic and Mg (OH)2 is weakly basic and do not dissolve in NaOH solution. When heated to 800°C, NaN03 gives, (a)Na + N2 + O2 (b) NaNO2 + O2 (c) Na2O + O2 + N2 (d)NaN3 + O2, Question 4. Magnesium atom has small size so electrons are strongly bound to the nucleus. Thus, it has the highest charge density and hence attracts the water molecules more strongly. Answer: MgSO4,7H2O. Question 6. (a) Lithium iodide is more covalent than lithium fluoride. Which out of the following can be used to store an alkali metal? 2Na- Hg + 2H20——>2NaOH +H2 +Hg It is prepared by heating CaC2 with N2 at high temperature. (3) Silver, lead, and mercury(I) compounds are insoluble. In the final analysis, the table your teacher wants you to use is the most correct one for you to use. Lithium Nitrate , JPCRD, 2010 , 39 , 033104. Question 3. (b) Valence electrons of alkali metals like Na and K easily absorb energy from the JKBOSE Class 12th Chemistry Official Guess/Model Paper 2020-21, NCERT Solutions for Class 11 History Chapter 11 Paths to Modernization, NCERT Solutions for Class 11 History Chapter 10 Displacing Indigenous Peoples, NCERT Solutions for Class 11 History Chapter 9 The Industrial Revolution, JKSSB Panchayat Accounts Assistant Result Declared – Check here, JKBOSE Class 12th Biology Official Guess/Model Paper 2020-21, JKBOSE Class 11th English Official Guess/Model Paper 2020-21, General Characteristics of the Compounds of the Alkali Metals, Biological Importance of Sodium and Potassium, General Characteristics of Compounds of the Alkaline Earth Metals, Biological Importance of Magnesium and Calcium. Question 4. (c) 4. Alkali salts are all ionic which refers to the bonding mechanism of the crystalline solid. Reactivity of halogen towards particular alkali metal follows the order F 2 > Cl 2 > Br 2 > I 2 ... Alkali metal nitrates (MNO 3) decompose on strong heating to corresponding nitrite and O 2 ... as corresponding slats of other alkali metals are freely soluble vi) Li form imide ( LiNH) with ammonia while other alkali metals form amides ( MNH 2) What is the effect of heat on the following compounds (Give equations for the reactions)? Answer: (a) Due to its lowest ionization energy, Cs is considered as the most electropositive element. What is soda ash? Answer: Physical properties of alkali metals: Question 2. (a) It is used in the manufacturing of soap paper, artificial silk etc. Q9. The rules form a list so when they seem to contradict, the higher one takes precedent. Lithium shows a diagonal relationship with, (a) sodium (b) silicon (c) nitrogen (d)magnesium, (a) an ammoniacal brine solution is carbonated with CO2, forming NaHCO3 which on decomposition at 150°C produces Na2CO3, (b) a sodium amalgum reacts with water to produce NaOH which gives Na2CO3 on reacting with CO2, (c) A brine solution is made to react with BaCO3 to produce Na2CO3. On moving down the group, their solubility decreases. Answer: Alkali metals have only one valence electron per metal atom. Thus Lil– has more covalent character than LiF. Sulphates of both group 1 and group 2 metals are stable towards heat. Question 4. Answer: 1. That’s why they always exist in combined state in nature. At anode: Na+ ions participate in the transmission of nerve signals, in regulating the flow of water across cell membranes. Why are lithium salts commonly hydrated and those of the other alkali metal ions usually anhydrous? (a) Na (b) K (c) Rb (d) Cs Question 32. Don't worry! Answer: Question 3. Lead and Silver rule 3. v) Solubility in liquid ammonia Why is LiF almost insoluble in water whereas LiCl soluble not only in water but also in acetone? Potassium carbonate cannot be prepared by Solvay process. (ii) Both BaO and BaSO4 are ionic compounds but the hydration energy of BaO is higher than the lattice energy therefore it is soluble in water. (a) What makes lithium to show properties uncommon to the rest of the alkali metals? Answer:  (i) Caustic soda Which of the following is used in photoelectric cells? Describe the importance of the following: Mg2+(aq) + 2e– ———-> Mg(s) Compare the alkali metals and alkaline earth metals with respect to (i) ionization enthalpy, (ii) basicity of oxides, (iii) solubility of hydroxides. Question 3. (ii) 2Na + O2 ———> Na2O2 Alkaline earth metals are Question 8. Why? Answer: Fused NaOH. 4. At cathode: Rule: Important Exceptions 1. (b) What happens when alkali metals are dissolved in ammonia? (ii) Sodium hydroxide is manufactured by electrolysis of an aqueous solution of NaCl (brine) in Castner-Kellner cell. (i) Limestone (ii) Cement (iii) Plaster of Paris. Carbonates of alkaline earth metals are insoluble in water. © NCERTGUESS.COM 2020 - Powered by PipQuantum Inc . (iii) Sodium peroxide: However, in case of corresponding magnesium and calcium compounds, the cations have smaller sizes and more magnitude of positive charge. (b) Because the discharge potential of alkali metals is much higher than that of hydrogen, therefore when the aqueous solution of any alkali metal chloride is subjected to electrolysis, H2, instead of the alkali metal, is produced at the cathode. Answer: Question 12. Answer: This is due to the reason that potassium bicarbonate (KHCO3) formed as an intermediate (when CO2 gas is passed through ammoniated solution of potassium chloride) is highly soluble in water and cannot be separated by filtration. Silver nitrite and potassium perchlorate are considered slightly soluble. of alkaline earth metals are higher than those of the corresponding alkali metals. Answer: Question 18. Also, the solubility increases as we move down the group. What is the general name for elements of group 1 ? Keep in mind that there will be slight variations from table to table. Question 19. (b) a sodium amalgum reacts with water to produce NaOH which gives Na2CO3 on reacting with CO2 Li+ < Na+ 2NaOH + H2O2. Answer: They are always univalent because after losing one electron, they aquire nearest inert gas configuration.Li+ forms largest hydrated cations because it has the highest hydration energy. Nitrates can be prepared by reacting the corresponding oxides, hydroxides and carbonates with nitric acid. Answer: It is because ionization enthalpy ∆Hi of potassium = 419 kJ mol -1. Alkali earth metals. Answer: Due to small size, the ionization enthalpies of Be and Mg are much higher than those of other alkaline earth metals. Question 5. (c) 10. The reducing property of alkali metals follows the order Give the chemical formula of Epsom salt. (ii) BaO is soluble but BaSO4is insoluble in water. This is because their hydration energies decreases more rapidly than their lattice energies. [ M = Be, Mg, Ca, Sr, Ba] (b) Carbonates- (b) Lithium is the only alkali metal to form a nitride directly. Question 8. (d) Li is the best reducing agent in aqueous solution. (iv)Sodium carbonate is obtained by Solvay ammonia process. Their solubility in water increases on moving down the group because their lattice enthalpies decrease more rapidly than the hydration enthalpies. Thermal stability of carbonates of group 2 increases down the group because Lattice energy goes no increasing due to increase in ionic character. What happens when crystals of washing soda are exposed to air? When these electrons return to the ground state, the energy is emitted in the form of light. Essentially, all alkali metal (Li +, Na +, K +, Rb +, Cs +) and ammonium (NH 4 +) salts are soluble. Carbonates of metal: Thermal stabilityThe carbonates of alkali metals except lithium carbonate are stable to heat. Question 17. The oxides of calcium, strontium, and barium are basic and the hydroxides are strongly basic. Lithium shows a diagonal relationship with In fact, these metals can precipitate from their salt solutions as carbonates.Nitrates: Thermal stabilityNitrates of alkali metals,except LiNO3, decompose on strong heating forming nitrites and oxygen. How is it prepared? (iii) Sodium peroxide dissolves in water? Mg is the main pigment for the absorption of light in plants. As a result, these metals easily emit electrons on exposure to light. Solution for Which of the statement is false regarding solubility rule A. (a) Na2O2 and water Answer: Sodium ions: Question 25. No common ones. BeCO 3 is least stable and BaCO 3 is most stable. What is the mixture of CaC2 and N2 called? You can check out similar questions with solutions below. (iii) Sulphates. (a) The mobilities of the alkali metal ions in aqueous solution are Li+ < Na+