S-BLOCK ELEMENT (Test-36)

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1 S-BLOCK ELEMENT (Test-36) READ THE INSTRUCTIONS CAREFULLY 1. The test is of 2 hours duration. 2. The maximum marks are This test consists of 70 questions. 4. Keep your mobiles switched off during Test in the Halls. Section A (Single Correct Choice Type) Negative Marking This Section contains 43 multiple choice questions. Each question has four choices A), B), C) and D) out of which ONLY ONE is correct. (Mark only One choice) 43 3 = 129 Marks 1. Which of the following alkaline earth metal sulphates is least soluble in water? a. BaSO 4 b. MgSO 4 c. SrSO 4 d. CaSO 4 2. Consider the following abbreviations for hydrated alkali metal ions: X = [Li(H 2 O) n ] + ; Y = [K(H 2 O) n ] + ; Z = [Cs(H 2 O) n ] + Which is the correct order of size of these hydrated alkali metal ions? a. X > Y > Z b. Z > Y > X c. X = Y = Z d. Z > X > Y 3. Which is correct order of solubility in water? a. Ba(OH) 2 < Mg(OH) 2 b. BaCO 3 > CaCO 3 c. CaSO 4 < MgSO 4 d. Ca(OH) 2 = Mg(OH) 2 4. Correct order of stability of group IIA metal carbonates is: a. MgCO 3 > CaCO 3 > SrCO 3 > BaCO 3 b. BaCO 3 > SrCO 3 > CaCO 3 > MgCO 3 c. SrCO 3 > BaCO 3 > CaCO 3 > MgCO 3 d. CaCO 3 > MgCO 3 > BaCO 3 > SrCO 3 5. Which of the following has highest hydration energy? a. MgCl 2 b. CaCl 2 c. BaCl 2 d. SrCl 2 6. Match the List I with List II and select the correct answer using the code given below the lists: List I List II P. Strongest reducing agent in ueous solution 1. Magnesium Q. Does not give flame colouration 2. Caesium R. Forms peroxides on heating with excess oxygen 3. Lithium S. Used in photoelectric cells 4. Sodium P Q R S P Q R S a b c d Dr. Sangeeta Khanna Ph.D 1 CHEMISTRY COACHING CIRCLE

2 7. The increasing stability of alkali metal peroxides and superoxides is due to a. the size of the metal ion increases down the group. b. the large anions are stabilized by large cations c. both (a) and (b) d. more electropositive nature of metal 8. Which of the following order is correct for the thermal stability of alkali metal carbonates? a. Li 2 CO 3 < K 2 CO 3 < Na 2 CO 3 < Cs 2 CO 3 b. Cs 2 CO 3 < Rb 2 CO 3 < K 2 CO 3 < Na 2 CO 3 < Li 2 CO 3 c. Na 2 CO 3 < K 2 CO 3 < Cs 2 CO 3 < Li 2 CO 3 < RbCO 3 d. Li 2 CO 3 < Na 2 CO 3 < K 2 CO 3 < Rb 2 CO 3 < Cs 2 CO 3 9. When LiNO 3 is heated, it gives oxide, Li 2 O, whereas other alkali metal nitrates decompose to give corresponding a. nitrite b. peroxide c. both nitrite and oxide d. none of these 10. Which of the following has correct increasing basic strength? a. MgO < BeO < CaO < BaO b. BeO < MgO < CaO < BaO c. BaO < CaO < MgO < BeO d. CaO < BaO < BeO < MgO. 11. The standard reduction potentials at 25 C of Li + /Li, Ba 2+ /Ba, Na + /Na and Mg 2+ /Mg are -3.05, -2.73, and volt respectively. Which one of the following is the strongest oxidizing agent? a. Na + b. Li + c. Ba 2+ d. Mg Which of the following electronic configurations corresponds to an element with the lowest ionization energy? a. 1s 2 2s 2 2p 3 b. 1s 2 2p 2 2p 5 c. 1s 2 2s 2 2p 2 d. 1s 2 2s 2 2p 6 3s Which of the following sulphates does not form hydrated salt. a. BaSO 4 b. Na 2 SO 4 c. CaSO 4 d. MgSO The alkali metal which can emit its outermost electron under the influence of even candle light is: a. Na b. Rb c. K d. Cs Air H O H2O 15. Mg X Y 2 Z A Heat Colourless gas Substances, X, Y, Z and A are respectively: a. Mg 3 N 2, MgO, NH 3, NH 4 OH b. Mg(NO 3 ) 2, MgO, H 2, NH 4 OH c. MgO, Mg 3 N 2, NH 3, NH 4 OH d. Mg(NO 3 ) 2, MgO 2, H 2 O 2, NH Which of the following on thermal decomposition yields a basic as well as an acidic oxide? a. KClO 3 b. Na 2 CO 3 c. NaNO 3 d. CaCO Lattice energies of AF 2, BF 2, CF 2 and DF 2 are 2906, , and 2367 kj mol -1 respectively. Hydration energies of A 2+, B 2+, C 2+, D 2+ and F are 2494, , -1577, and -457 kj mol -1 respectively. Which of the fluorides is least soluble in water? a. AF 2 b. BF 2 c. CF 2 d. DF 2 Dr. Sangeeta Khanna Ph.D 2 CHEMISTRY COACHING CIRCLE

3 18. 1 mole mixture of Li 2 CO 3 and K 2 CO 3 on strongly heating gave 0.25 mol of CO 2. The two compounds are present in the ratio 1 : y (i.e., Li 2 CO 3 : K 2 CO 3 ). The value of y is: a. 3 b. 5 c. 7 d Be 2 C + 4H 2 O 2X + CH 4 X + 2HCl + 2H 2 O Y X and Y formed in the above two reactions is a. BeCO 3 and Be(OH) 2 respectively b. Be(OH) 2 and BeCl 2 respectively c. Be(OH) 2 and [Be(H 2 O) 4 ]Cl 2 respectively d. [Be(OH) 4 ] 2 and BeCl 2 respectively 20. Select the pair in which the first halide exists as a hydrate but the second halide does not form a hydrate? a. KCl & MgCl 2 b. CaCl 2 & NaCl c. NaCl & KCl d. MgCl 2 & CaCl In Solvay ammonia process, sodium bicarbonate is precipitated due to reaction of a. NH 3 & CO 2 b. CO 2 + NaOH c. Reaction of brine solution with NH 3 & CO 2 d. NaCl & CO A metal M reacts with N 2 to give a compound A (M 3 N). A on heating at high temperature gives back M and A on reacting with H 2 O gives a gas B an alkaline gas. B intensifies colour of CuSO 4 solution when passes through it and give Nessler Reagent test. A and B can be a. Mg and NH 3 b. Na and NH 3 c. Li and NH 3 d. Al and NH Beryllium shows diagonal relationship with aluminium. Which of the following similarity is incorrect? a. Be 2 C like Al 4 C 3 yields methane on hydrolysis b. Be like Al become passive by HNO 3 c. Be(OH) 2 like Al(OH) 3 is basic d. Be forms beryllates and Al forms aluminates 24. The compound A on heating gives a colourless gas and a residue that is dissolved in water to obtain B. When Excess of CO 2 is bubbled through ueous solution of B, Compound C is formed which is not recovered in the solid form. Solid C on gentle heating gives back A. The compound is: a. CaCO 3 b. Na 2 CO 3 c. K 2 CO 3 d. CaSO 4. 2H 2 O 25. X is used for immobilizing the affected part of organ when there is a sprain. X is obtained on heating gypsum at 393 K. The number of expelled water molecules when X is obtained by heating 2 molecules of gypsum is a. 7 b. 5 c. 3 d Which of the following is used to prepare nitrolim fertilizer a. CaC 2 + N 2 b. CaO + N 2 c. Ca(OH) 2 + SO 2 d. Al 2 O 3 + N Which of the following is added to cement to slow down its setting a. Epsom salt b. Gypsum c. Silica d. NaOH 28. Which of the following is plaster of Paris a. CaSO 4 2H 2 O b. 2CaSO 4 H 2 O c. CaSO 4 d. MgSO 4 7H 2 O Dr. Sangeeta Khanna Ph.D 3 CHEMISTRY COACHING CIRCLE

4 29. A solution of sodium metal in liquid ammonia is strongly reducing due to presence of a. Sodium atom b. Sodium amide c. Sodium ion d. Solvated electron 30. Which of the following is correct order of conductance of solution a. Li Na K Rb b. Rb K Na Li c. Rb Na K Li d. All have same conductance 31. A metal M readily forms its sulphate MSO 4 which is water soluble. It form oxide MO on heating. Its Hydroxide is water soluble. Metal M is a. Na b. Be c. Li d. Ba 32. Property of all the alkaline earth metals that increases with their atomic number is a. Ionization energy b. Solubility of hydroxide c. Solubility of their sulphate d. electronegativity 33. The solubility of carbonates decreases down the magnesium group due to decrease in a. lattice energies of solids b. Hydration energies of cation c. interionic attraction d. entropy of solution 34. KO 2 is used in oxygen cylinders in space & submarines because it a. Absorbs CO 2 & increases O 2 content b. eliminate moisture c. absorbs CO 2 d. produces ozone 35. Which of the following is used to detect CO 2 a. Ca(OH) 2(S) b. Milk of lime c. Lime water d. Mg(OH) Na 2 CO 3 is formed when NH 3, CO 2 & Brine react in solvays process. This method cannot be used to prepare K 2 CO 3, due to a. No displacement is possible b. KCl is not available c. KHCO 3 cannot be precipitated due to its solubility d. KHCO 3 is thermally stable 37. The ueous solution of Na 2 CO 3 is basic because: a. It is basic in nature b. 2 3 CO reacts with water to produce OH ions in solution c. It acts as a carbonate of alkali d. 2 3 CO reacts with water to produce H + ions in solution 38. The standard electrode potential of Rubidium and caesium are similar because: a. of the hydration energy released when Rubidium is added to water will compensate its high ionisation energy b. they both react with water and lose electrons c. their ionisation energies are similar d. they belong to the same group of periodic table Dr. Sangeeta Khanna Ph.D 4 CHEMISTRY COACHING CIRCLE

5 39. The correct order of stability of hydrides of alkali metals is: a. LiH > NaH > KH > RbH b. NaH > KH > RbH > LiH c. RbH > KH > NaH > LiH d. LiH > RbH > KH > NaH 40. Water glass is: a. Sodium silicate b. Beryllium aluminium c. Aluminium silicate d. Sodium solution 41. Pick out the wrong statement: a. The electronegativities of all the alkali metals are the same b. Lithium resembles magnesium in some respects though placed in a different group c. The electropositive character of alkali metals increases with increase in atomic number d. Alkali metals are strong reducing agents 42. Sodium conducts electricity because it a. is a soft metal b. has mobile electrons c. gives hydrogen with water d. has one electron in the outermost orbital 43. Potassium is kept in: a. Alcohol b. Water c. Kerosene d. Liquid ammonia Section B (Assertion & Reason Type) Negative Marking This Section contains 8 multiple choice questions. Each question has four choices A), B), C) and D) out of which ONLY ONE is correct. (Mark only One choice) 8 4 = 32 Marks (A) If both assertion and reason are true and reason is the correct explanation of assertion. (B) If both assertion and reason are true but reason is not the correct explanation of assertion. (C) If assertion is true but reason is false. (D) If both assertion and reason are false. 1. Assertion :- The carbonate of lithium decomposes easily on heating to form lithium oxide and CO 2. Reason :- Lithium being very small in size polarizes large carbonate ion leading to the formation of more stable Li 2 O and CO 2. a. (a) b. (b) c. (d) d. (d) 2. Assertion :- Helium and beryllium have similar outer electronic configuration of type ns 2. Reason :- Both are chemically inert. a. (a) b. (b) c. (d) d. (d) 3. Assertion :- Lithium resembles magnesium diagonally placed in next group. Reason :- Because both have same valency. a. (a) b. (b) c. (d) d. (d) 4. Assertion: Li resembles Mg. Reason: Li + has same polarizing power as Mg +2 Dr. Sangeeta Khanna Ph.D 5 CHEMISTRY COACHING CIRCLE

6 5. Assertion: s-block elements are highly electropositive. Reason: The valence electrons present in s-orbital are loosely held. 6. Assertion: The first ionization energy of Be is greater than that of B. Reason: 2p-orbital is lower in energy than 2s-orbital. 7. Assertion: Plaster of Paris on hydration changes to Monoclinic Gypsum Reason: Setting of plaster of Paris is not reversible. 8. Assertion: Oxidation electrode potential of Ca, Sr and Ba are nearly same. Reason: Energy released on hydration compensate the energy required for ionisation and sublimation. SECTION C (Paragraph Type) Negative Marking [-1] This Section contains 3 paragraphs. Each of these questions has four choices A), B), C) and D) out of which ONLY ONE is correct. (Mark only one) 9 3 = 27 Marks Passage 1 The atomic and ionic radii of the alkaline metals are smaller than those of the corresponding alkali metals in the same periods. This is due to increased nuclear charge in these elements. Within the group the atomic and ionic radii increase with increase in atomic number. The alkaline earth metals have low ionization enthalpies due to fairly large size of the atoms. Since the atomic size increases down the group, their ionization enthalpy decreases. The first ionisation enthalpies of the alkaline earth metals are higher than those of the corresponding Group 1 metals. Like alkali metals, the alkaline earth metals are strong reducing agents. This is indicated by large negative values of their reduction potentials. However their reducing power is less than those of their corresponding alkali metals. Beryllium has less negative value compared to other alkaline earth metals. However, its reducing nature is due to large hydration energy associated with the small size of Be 2+ ion and respectively large value of the atomization enthalpy of the metal. 1. Which of the following ions has the largest ionic radius? a. Be 2+ b. Mg 2+ c. Ca 2+ d. Sr The decreasing order of the second ionisation enthalpy of K, Ca and Ba is a. K > Ca > Ba b. Ca > Ba > K c. Ba > K > Ca d. K > Ba > Ca 3. Which of the alkaline earth metals is the strongest reducing agent? a. Ca b. Sr c. Ba d. Mg Passage- 2 Both alkali and alkaline earth metals and their salts impart characteristic colours to the flame. This is because the heat from the flame excites the outermost orbital electron to a higher energy level. When the excited electron comes back to the ground state, there is emission of radiation in the visible region. Therefore, the flame test is helpful in their detection in qualitative analysis and estimation by flame photometry. Dr. Sangeeta Khanna Ph.D 6 CHEMISTRY COACHING CIRCLE

7 4. Sodium chloride imparts golden yellow colour to the Bunsen flame. This can be interpreted due to: a. Due to low ionization potential of sodium; electronic transition is possible by flame b. photosensitivity of sodium c. sublimation of metallic sodium to give yellow vapours d. emission of energy absorbed as a radiation in the ultraviolet region. 5. Which of the following pairs do not impart any colour to the flame? a. Ca and Mg b. Be and Ba c. Na and K d. Be and Mg 6. A substance which gives a brick red flame and breaks down on heating giving oxygen and a brown gas is: a. calcium carbonate b. magnesium carbonate c. magnesium nitrate d. Calcium nitrate Passage 3 All the alkali metals have one valence electron, ns 1 outside the noble gas core. The loosely held s- electron in the outermost valence shell of these elements makes them the most electropositive metals. They readily lose electron to give monovalent M + ions. Hence they are never found in free state in nature. The hydration enthalpies of alkali metal ions decrease with increase in ionic sizes. The alkali metals and their salts impart characteristic colour to an oxidizing flame. This is because the heat from the flame excites the outermost orbital electron to a higher energy level. When the excited electron comes back to the ground state, there is emission of radiation in the visible region. Alkali metals can therefore, be detected by the respective flame tests and can be determined by flame photometry or atomic absorption spectroscopy. 7. The element with atomic number 19 is similar in physical and chemical properties to the element with atomic number a. 6 b. 9 c. 10 d Which has minimum hydration energy? a. K + b. Li + c. Ca 2+ d. Al Which of the following when introduced into the Bunsen s flame gives pink violet colour? a. NaCl b. BaCl 2 c. CsCl d. KCl SECTION D (Multiple Correct Choice Type) No Negative Marking This Section contains 8 multiple choice questions. Each question has four choices A), B), C) and D) out of which ONE OR MORE may be correct. 8 4 = 32 Marks 1. Mark the correct statement about lithium: a. Lithium metal is not affected by air b. When burnt in oxygen, lithium metal prefer to form superoxide LiO 2 c. Lithium combines with nitrogen directly to form lithium nitride d. Lithium has great tendency to form hydrates but least reactive in H 2 O, among alkali metal. 2. Which of the following combine(s) with nitrogen to form nitride? a. Li b. Mg c. Na d. K Dr. Sangeeta Khanna Ph.D 7 CHEMISTRY COACHING CIRCLE

8 3. Which of the following pairs of elements show diagonal relationship? a. Na & Li b. Be and Al c. Li & Mg d. B & Carbon 4. Which of the following cannot be made anhydrous by heating a. MgCl 2 6H 2 O b. BaCl 2 2H 2 O c. CaCl 2 2H 2 O d. AlCl 3 6H 2 O 5. Which of the following is the correct order of solubility a. BeF 2 > BaF 2 > SrF 2 > MgF 2 b. BeCl 2 > MgCl 2 > CaCl 2 > SrCl 2 c. Be(OH) 2 > Mg(OH) 2 > Ca(OH) 2 > Sr(OH) 2 d. BeSO 4 > MgSO 4 > CaSO 4 > SrSO 4 6. Which of the following chlorides is (are) soluble in pyridine (organic solvent) a. BaCl 2 b. LiCl c. NaCl d. BeCl 2 7. Which of the following metals are stored in Kerosene a. Be b. T c. Cs d. Rb 8. Which of the following is correct order as indicated a. Li < K < Na < Rb < Cs (density) b. Li 2 O < Na 2 O < K 2 O < Rb 2 O < Cs 2 O (solubility) c. NaF < NaCl < NaBr < NaI (negative d. Li < Na < K < Rb < Cs (softness) 0 f H ) SECTION E (Matrix-Match Type) No Negative marking This Section contains 2 questions. Each question has four choices (A, B, C and D) given in Column I and five statements (p, q, r, and s) in Column II. 8 2 = 16 Marks 1. Match column I with column II. (Single Match) Column I Column II (A) Ra (p) Lightest alkaline earth metal (B) Ca (q) Apple green flame colouration (C) Mg (r) Radioactive element (D) Ba (s) Lowest m.pt. among group 2 metals 2. Match column I with column II. (One or More than One Match) Column I Column II (A) Na (p) Superoxide (B) Cs (q) Coloured oxide (C) K (r) Stable peroxide (D) Li (s) Normal oxide Dr. Sangeeta Khanna Ph.D 8 CHEMISTRY COACHING CIRCLE

THE s- BLOCK ELEMENTS General electronic configuration- [ noble gas] ns 1-2

THE s- BLOCK ELEMENTS General electronic configuration- [ noble gas] ns 1-2 GROUP 1 ELEMENTS : ALKALI METALS General electronic configuration- [ noble gas] ns 1 Members- Li, Na, K, Rb, Cs, Fr Atomic and