11th Chemistry Volume · Part

EVALUATION . For alkali metals, which one of the following trends is incorrect ? a) Hydration energy : Li > Na > K > Rb b) Ionisation energy : Li > Na > K > Rb c) Density : Li < Na < K < Rb d) Atomic size : Li < Na < K < Rb . Which of the following statements is incorrect ?

a) Li + has minimum degree of hydration among alkali metal cations. b) The oxidation state of K in KO is + c) Sodium is used to make Na / Pb alloy d) MgSO is readily soluble in water . Which of the following compounds will not evolve H gas on reaction with alkali metals ? a) ethanoic acid b) ethanol c) phenol d) none of these .

Which of the following has the highest tendency to give the reaction M + (g) Aqueous Medium M + (aq) a) Na b) Li c) Rb d) K . sodium is stored in a) alcohol b) water c) kerosene d) none of these . RbO is a) superoxide and paramagnetic b) peroxide and diamagnetic c) superoxide and diamagnetic d) peroxide and paramagnetic . Find the wrong statement a) sodium metal is used in organic qualitative analysis b) sodium carbonate is soluble in water and it is used in inorganic qualitative analysis c) potassium carbonate can be prepared by solvay process d) potassium bicarbonate is acidic salt .

Lithium shows diagonal relationship with a) sodium b) magnesium c) calcium d) aluminium . Incase of alkali metal halides, the ionic character increases in the order a) MF < MCl < MBr < MI b) MI < MBr < MCl < MF c) MI < MBr < MF < MCl d) none of these . In which process, fused sodium hydroxide is electrolysed for extraction of sodium ? a) Castner's process b) Cyanide process c) Down process d) All of these .

The product obtained as a result of a reaction of nitrogen with CaC is (NEET - Phase I) a) Ca(CN) b) CaN c) Ca(CN) d) Ca N . Which of the following has highest hydration energy a) MgCl b) CaCl c) BaCl d) SrCl . Match the flame colours of the alkali and alkaline earth metal salts in the bunsen burner (p) Sodium ( ) Brick red (q) Calcium ( ) Yellow (r) Barium ( ) Lilac (violet) (s) Strontium ( ) Apple green (t) Cesium ( ) Crimson red (u) Potassium ( ) Blue a) p - , q - , r - , s - , t - , u - b) p - , q - , r - , s - , t - , u - c) p - , q - , r - , s - , t - , u - d) p - , q - , r - , s - , t - , u - . Assertion : Generally alkali and alkaline earth metals form superoxides Reason : There is a single bond between O and O in superoxides.

a) both assertion and reason are true and reason is the correct explanation of asser- tion b) both assertion and reason are true but reason is not the correct explanation of assertion c) assertion is true but reason is false d) both assertion and reason are false . Assertion : BeSO is soluble in water while BaSO is not Reason : Hydration energy decreases down the group from Be to Ba and lattice energy remains almost constant. a) both assertion and reason are true and reason is the correct explanation of asser- tion b) both assertion and reason are true but reason is not the correct explanation of assertion c) assertion is true but reason is false d) both assertion and reason are false . Which is the correct sequence of solubility of carbonates of alkaline earth metals ?

a) BaCO > SrCO > CaCO > MgCO b) MgCO > CaCO > SrCO > BaCO c) CaCO > BaCO > SrCO > MgCO d) BaCO > CaCO > SrCO > MgCO . In context with beryllium, which one of the following statements is incorrect ? (NEET Phase - ) a) It is rendered passive by nitric acid b) It forms Be C c) Its salts are rarely hydrolysed d) Its hydride is electron deficient and polymeric . The suspension of slaked lime in water is known as (NEET Phase - II) a) lime water b) quick lime c) milk of lime d) aqueous solution of slaked lime .

A colourless solid substance (A) on heating evolved CO and also gave a white resi- due, soluble in water. Residue also gave CO when treated with dilute HCl. a) Na CO b) NaHCO c) CaCO d) Ca(HCO ) . The compound (X) on heating gives a colourless gas and a residue that is dissolved in water to obtain (B).

Excess of CO is bubbled through aqueous solution of B, C is formed. Solid (C) on heating gives back X. (B) is a) CaCO b) Ca(OH) c) Na CO d) NaHCO . Which of the following statement is false ?

(NEET - Phase - I) a) Ca + ions are not important in maintaining the regular beating of the heart b) Mg + ions are important in the green parts of the plants c) Mg + ions form a complex with ATP d) Ca + ions are important in blood clotting . The name 'Blue John' is given to which of the following compounds ? a) CaH b) CaF c) Ca (PO ) d) CaO . Formula of Gypsum is a) CaSO .

2H O b) CaSO . ½ H O c) CaSO . H O d) 2CaSO . 2H O .

When CaC is heated in atmospheric nitrogen in an electric furnace the compound formed is a) Ca(CN) b) CaNCN c) CaC N d) CaNC . Among the following the least thermally stable is (a) K CO b) Na CO (c) BaCo d) Li CO II. Write brief answer to the following questions: . Why sodium hydroxide is much more water soluble than sodium chloride?

. Write the chemical equations for the reactions involved in solvay process of preparation of sodium carbonate. . An alkali metal (x) forms a hydrated sulphate, X SO .

10H O. Is the metal more likely to be sodium (or) potassium. . Write balanced chemical equation for each of the following chemical reactions.

(i) Lithium metal with nitrogen gas (ii) heating solid sodium bicarbonate (iii) Rubidum with oxygen gas (iv) solid potassium hydroxide with CO (v) heating calcium carbonate (vi) heating calcium with oxygen . Discuss briefly the similarities between beryllium and aluminium. . Give the systematic names for the following (i) milk of magnesia (ii) lye (iii) lime (iv) Caustic potash (v) washing soda (vi) soda ash (v) trona .

Substantiate Lithium fluoride has the lowest solubility among group one metal fluorides. . Mention the uses of plaster of paris . Beryllium halides are covalent whereas magnesium halides are ionic why?

. Alkaline earth metal (A), belongs to 3rd period reacts with oxygen and nitrogen to form compound (B) and (C) respectively. It undergoes metal displacement reaction with AgNO solution to form compound (D). Identify A,B.C and D.

. Write balanced chemical equation for the following processes (a) heating calcium in oxygen (b) heating calcium carbonate (c) evaporating a solution of calcium hydrogen carbonate (d) heating calcium oxide with carbon . Explain the important common features of Group elements. .

Discuss the similarities between beryllium and aluminium. . Why alkaline earth metals are harder than alkali metals. .

How is plaster of paris prepared? . Give the uses of gypsum. .

Describe briefly the biological importance of Calcium and magnesium. . Which would you expect to have a higher melting point, magnesium oxide or magnesium fluoride? Explain your reasoning.

Important Compounds Chemical Properties Li O Na O MO M = K, Rb, Cs +O +H +X MH (M= Li, K, Na, Rb, Cs) Mx M= Li, Na, K, Rb , Cs X = F, Cl, Br, I Physical Properties . Common Oxidation state: + . Atomic & Ionic Radii Increases down the group . IE, EA, EN Decreases down the group Alkali Metals Li, Na, K, Rb, Cs, Fr NaOH Na CO NaHCO NaCl +H O MOH (Li, Na, K, Rb, Cs) +C Li C HC ≡ CH MC ≡ CM ( M = Na , K , Rb , Cs ) CONCEPT MAP Flame test of alkali and alkaline earth elements (Virtual Lab) Step – Open the Browser and type the URL given (or) Scan the QR Code.

Just click the view button on the Flame test panel. This will open a flame test window as shown in the figure. Step – Follow the instrutions to perform a virtual flame test. .

Click on the wire loop ( ). . Move the wire loop to the cleaning solution ( ). Click on the cleaning solution.

The wire must be cleaned before each test to ensure there is no other salt on the loop. . Move the wire loop to the salt solution you want to test ( ). Click on the salt solution.

. Move the wire loop to the flame ( ) and click on it. . You will see the characteristic colour change in the flame with respect to the metal ion By using this virtual lab you can perform the flame test of different alkali and alkali earth metals and see the colour of the flame produced.

Please go to the URL free-curriculumresources/virtual_ lab/ / / , , / (or) Scan the QR code on the right side EVALUATION I. Choose the best answer . Gases deviate from ideal behavior at high pressure. Which of the following statement(s) is correct for non-ideality?

a) at high pressure the collision between the gas molecule become enormous b) at high pressure the gas molecules move only in one direction c) at high pressure, the volume of gas become insignificant d) at high pressure the intermolecular interactions become significant . Rate of diffusion of a gas is a) directly proportional to its density b) directly proportional to its molecular weight c) directly proportional to its square root of its molecular weight d) inversely proportional to the square root of its molecular weight . Which of the following is the correct expression for the equation of state of van der Waals gas? ( ) ( ) a P a n V nb nRT       ( ) ( ) b P na n V nb nRT       ( ) ( ) c P an nb nRT       ( ) ( ) d P n a nb nRT       .

When an ideal gas undergoes unrestrained expansion, no cooling occurs because the molecules a) are above inversion temperature b) exert no attractive forces on each other c) do work equal to the loss in kinetic energy d) collide without loss of energy . Equal weights of methane and oxygen are mixed in an empty container at K. The fraction of total pressure exerted by oxygen is ( ) a ( ) b ( )c ( ) d . The temperature at which real gases obey the ideal gas laws over a wide range of pressure is called a) Critical temperature b) Boyle temperature c) Inversion temperature d) Reduced temperature .

In a closed room of m a perfume bottle is opened up. The room develops a smell. This is due to which property of gases? a) Viscosity b) Density c) Diffusion d) None .

A bottle of ammonia and a bottle of HCl connected through a long tube are opened simultaneously at both ends. The white ammonium chloride ring first formed will be a) At the center of the tube b) Near the hydrogen chloride bottle c) Near the ammonia bottle d) Throughout the length of the tube . The value of universal gas constant depends upon a) Temperature of the gas b) Volume of the gas c) Number of moles of the gas d) units of Pressure and volume. .

The value of the gas constant R is a) . dm atm . b) . cal mol - K - c) .

J mol - K - d) erg mol - K - . Use of hot air balloon in sports and meteorological observation is an application of a) Boyle’s law b) Newton’s law c) Kelvin’s law d) Brown’s law . The table indicates the value of van der Waals constant ‘a’ in (dm ) atm . mol - Gas O N NH CH a .

. . . The gas which can be most easily liquefied is a) O b) N c) NH d) CH .

Consider the following statements i) Atmospheric pressure is less at the top of a mountain than at sea level ii) Gases are much more compressible than solids or liquids iii) When the atmospheric pressure increases the height of the mercury column rises Select the correct statement a) I and II b) II and III c) I and III d) I, II and III . Compressibility factor for CO at K and . bar is . .

The molar volume of CO under these conditions is a) . dm b) . dm c) . dm d) .5dm .

If temperature and volume of an ideal gas is increased to twice its values, the initial pressure P becomes a) 4P b) 2P c) P d) 3P . At identical temperature and pressure, the rate of diffusion of hydrogen gas is times that of a hydrocarbon having molecular formula C n H 2n– . What is the value of n ? a) b) c) d) .

Equal moles of hydrogen and oxygen gases are placed in a container, with a pin-hole through which both can escape what fraction of oxygen escapes in the time required for one-half of the hydrogen to escape. (NEET phase I) a) b) c) d) . The variation of volume V, with temperature T, keeping pressure constant is called the coefficient of thermal expansion ie α = P ∂ ∂       . For an ideal gas α is equal to a) T b) T c) P d) none of these .

Four gases P, Q, R and S have almost same values of 'b' but their 'a' values (a, b are Vander Waals Constants) are in the order Q < R < S < P. At a particular temperature, among the four gases the most easily liquefiable one is a) P b) Q c) R d) S . Maximum deviation from ideal gas is expected from (NEET) a) CH (g) b) NH (g) c) H (g) d) N (g) . The units of Vander Waals constants 'b' and 'a' respectively a) mol L – and L atm mol – b) mol L and L atm mol c) mol – L and L atm mol – d) none of these .

Assertion : Critical temperature of CO is 304K, it can be liquefied above 304K. Reason : For a given mass of gas, volume is to directly proportional to pressure at constant temperature a) both assertion and reason are true and reason is the correct explanation of asser- tion b) both assertion and reason are true but reason is not the correct explanation of assertion c) assertion is true but reason is false d) both assertion and reason are false . What is the density of N gas at o C and . atm pressure?

(R = . L atm K– mol – ) a) . g/L b) . g/L c) .

g/L d) . g/L . Which of the following diagrams correctly describes the behaviour of a fixed mass of an ideal gas ? (T is measured in K) a) P b) PV c) d) All of these .

25g of each of the following gases are taken at o C and mm Hg pressure. Which of these will have the least volume ? a) HBr b) HCl c) HF d) HI II. Write brief answer to the following questions: .

State Boyle's law. . Name two items that can serve as a model for Gay Lusaac’ law and explain. .

Give the mathematical expression that relates gas volume and moles. . What are ideal gases? In what way real gases differ from ideal gases.

. Can a Van der Waals gas with a= be liquefied? explain. .

Suppose there is a tiny sticky area on the wall of a container of gas. Molecules hitting this area stick there permanently. Is the pressure greater or less than on the ordinary area of walls? .

Explain the following observations a) Aerated water bottles are kept under water during summer b) Liquid ammonia bottle is cooled before opening the seal c) The tyre of an automobile is inflated to slightly lesser pressure in summer than in winter d) The size of a weather balloon becomes larger and larger as it ascends up into larger altitude . Give suitable explanation for the following facts about gases. a) Gases don’t settle at the bottom of a container b) Gases diffuse through all the space available to them . Suggest why there is no hydrogen (H ) in our atmosphere.

Why does the moon have no atmosphere? . Explain whether a gas approaches ideal behavior or deviates from ideal behaviour if a) it is compressed to a smaller volume at constant temperature. b) the temperature is raised while keeping the volume constant c) more gas is introduced into the same volume and at the same temperature .

Which of the following gases would you expect to deviate from ideal behaviour under conditions of low temperature F , Cl or Br ? Explain. . Distinguish between diffusion and effusion.

. Aerosol cans carry clear warning of heating of the can. Why? .

Would it be easier to drink water with a straw on the top of Mount Everest? . Write the Van der Waals equation for a real gas. Explain the correction term for pressure and volume .

Derive the values of critical constants in terms of van der Waals constants. . Why do astronauts have to wear protective suits when they are on the surface of moon? .

When ammonia combines with HCl, NH Cl is formed as white dense fumes. Why do more fumes appear near HCl? . A sample of gas at °C at atm.

has a volume of . dm . When the temperature is raised to °C at atm does the volume of the gas increase? If so, calculate the final volume.

. A sample of gas has a volume of . dm at an unknown temperature. When the sample is submerged in ice water at °C, its volume gets reduced to .

dm . What is its initial temperature? . Of two samples of nitrogen gas, sample A contains .

moles of nitrogen in a vessel of volume of . dm at 298K, and the sample B is in a vessel of volume . dm at 298K. Calculate the number of moles in sample B.

. Sulphur hexafluoride is a colourless, odourless gas; calculate the pressure exerted by . moles of the gas in a steel vessel of volume . dm at .

°C, assuming ideal gas behaviour . Argon is an inert gas used in light bulbs to retard the vaporization of the tungsten filament. A certain light bulb containing argon at . atm and °C is heated to °C at constant volume.