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HOLIDAY HOME WORK FOR CLASS 11th
(CHEMISTRY) 2016-17
CHAPTER 1
1. Question based on atomic and molecular masses Atomic Mass Average Atomic
Mass, Molecular Mass, Formula Mass, mole concept and molar Masses, percentage
composition, Empirical Formula for Molecular Formula, Limiting Reagent.
1 Calculate the mass per cent of different elements present in sodium sulphate (Na2SO4).
2 Determine the empirical formula of an oxide of iron which has 69.9% iron and 30.1%
Dioxygen by mass.
3 How much copper can be obtained from 100 g of copper sulphate (CuSO4)?
4 In a reaction A + B2 -> AB2
Identify the limiting reagent, if any, in the following reaction mixtures.
(i) 300 atoms of A + 200 molecules of B (ii) 2 mol A + 3 mol B
(iii) 100 atoms of A + 100 molecules of B (iv) 5 mol A + 2.5 mol B (v) 2.5 mol A + 5 mol B
5 Determine the molecular formula of an oxide of iron in which the mass per cent of iron
and oxygen are 69.9 and 30.1 respectively.
6 A welding fuel gas contains carbon and hydrogen only. Burning a small sample of it in
oxygen gives 3.38 g carbon dioxide, 0.690 g of water and no other products. A volume of
10.0 L (measured at STP) of this welding gas is found to weigh 11.6 g. Calculate (i) empirical
formula, (ii) molar mass of the gas, and (iii) molecular formula.
7Calculate the amount of water (g) produced by the combustion of 16 g of methane.
reaction.
8 How many moles of methane are required to produce 22 g CO2 (g) after combustion?
9 A compound contains 4.07 % hydrogen,24.27 % carbon and 71.65 % chlorine.
Its molar mass is 98.96 g. What are its empirical and molecular formulas ?
10(i) Define the following terms. (Write the mathematical formulas related to terms)(a)
Mass percent (b) Molarity (c) Molality (d) Mole-fraction (e) Mass percent
(ii)Calculate the mass of sodium acetate (CH3COONa) required to make 500 mL of 0.375
molar aqueous solution. (Molar mass of sodium acetate is 82.0245 g mol–1).
11 Calculate the concentration of nitric acid in moles per litre in a sample which
has a density, 1.41 g mL–1 and the mass per cent of nitric acid in it being 69%.
12 What is the concentration of sugar (C12H22O11) in mol L–1 if its 20 g are
dissolved in enough water to make a final volume up to 2L?
13 If the density of methanol is 0.793 kg L–1, what is its volume needed for
making 2.5 L of its 0.25 M solution?
14 A sample of drinking water was found to be severely contaminated with
chloroform, CHCl3, supposed to be carcinogenic in nature. The level of
contamination was 15 ppm (by mass).
(i) Express this in percent by mass. (ii) Determine the molality of chloroform in
the water sample.
15 The density of 3 M solution of NaCl is 1.25 g mL–1. Calculate molality of the
solution.
16 How are 0.50 mol Na2CO3 and 0.50 M Na2CO3 different?
17 Which one of the following will have largest number of atoms?
(i) 1 g Au (s) (ii) 1 g Na (s) (iii) 1 g Li (s)(iv) 1 g of Cl2(g)
18 Calculate the molarity of a solution of ethanol in water in which the mole
fraction of ethanol is 0.040 (assume the density of water to be one).
19 Calculate the number of atoms in each of the following (i) 52 moles of Ar (ii)
52 u of He (iii) 52 g of He.
20 Calculate the molarity of NaOH in the solution prepared by dissolving its 4 g
in enough water to form 250 mL of the solution.
CHAPTER 2- STUCTURE OF ATOM
21. Write a note on the Spectral Lines for Atomic Hydrogen.
22. What are the frequency and wavelength of a photon emitted during a
transition from n = 5 state to the n = 2 state in the hydrogen atom?
23. Calculate the energy associated with the first orbit of He + .What is the
radius of this orbit?
24. What is the wavelength of light emitted when the electron in a hydrogen
atom undergoes transition from an energy level with n = 4 to an energy level
with n = 2?
25 How much energy is required to ionise a H atom if the electron occupies n =
5 orbit? Compare your answer with the ionization enthalpy of H atom ( energy
required to remove the electron from n =1 orbit).
26. What is the maximum number of emission lines when the excited electron of
a H atom in n = 6 drops to the ground state?
27.(i) The energy associated with first orbit in the hydrogen atom is –2.18 × 10
–18J atom–1. What is the energy associated with the fifth orbit?
(ii) Calculate the radius of Bohr‘s fifth orbit for hydrogen atom.
28. Calculate the wavenumber for the longest wavelength transition in the
Balmer series of atomic hydrogen.
29. What is the energy in joules, required to shift the electron of the hydrogen
atom from the first Bohr orbit to the fifth Bohr orbit and what is the
wavelength of the light emitted when the electron returns to the ground state?
The ground state electron energy is –2.18 X 10–11ergs.
30. The electron energy in hydrogen atom is given by En = (–2.18 X 10–18)/n2J.
Calculate the energy required to remove an electron completely from the n = 2
orbit. What is the longest wavelength of light in cm that can be used to cause
this transition?
31. What transition in the hydrogen spectrum would have the same wavelength
as the Balmer transition n = 4 to n = 2 of He+ spectrum?
32..Questions based on Dual behaviour of matter (de Broglie’s relation),
Heisenberg uncertainty principle.
33.What will be the wavelength of a ball of mass 0.1 kg moving with a velocity of
10 m s –1?
34. The mass of an electron is 9.1 X 10 kg. If its K.E. is 3.0 X10 –25 J, calculate
its wavelength.
35. Calculate the mass of a photon with wavelength 3.6 Å.
36. Calculate the wavelength of an electron moving with a velocity of 2.05 X
107ms–1
37 The mass of an electron is 9.1 X 10–31kg. If its K.E. is 3.0 X 10–25 J, calculate
its wavelength.
38 Why de Broglie‘s relation is not associated with ordinary objects.
39 Give the electronic configuration of first 30 elements.
40 Explain the exceptional configuration of copper and chromium.
41 Give the electronic configurations of the following ions: Cu2+ Cr3+ Fe2+ S2- Fe2+
O2- Na+
42. The unpaired electrons in Al and Si are present in 3p orbital. Which
electrons will experience more effective nuclear charge from the nucleus?
43 The bromine atom possesses 35 electrons. It contains 6 electrons in 2p
orbital, 6 electrons in 3p orbital and 5 electrons in 4p orbital. Which of these
electron experiences the lowest effective nuclear charge?
44 Draw the shapes of s,p,d & f orbitals.
CHAPTER3 PERIODICITY
.Questions based on electron gain enthalpy its Variation and factors affecting
it
45 Define the term electron gain enthalpy.
46 How does the electron gain enthalpy in a period and in a group? How do you
explain the variation?
47 Would you expect the second electron gain enthalpy of O as positive, more
negative or less negative than the first? Justify your answer?
48. Which of the following pairs of elements would have a more negative
electron gain enthalpy? (i) O or F (ii)F or Cl (iii) O or S.Give reason to support
your answer
Questions based on Ionization Enthalpy its Variation and factors affecting it.
49 What are the various factors due to which the ionization enthalpy of the
main group elements tends to decrease down a group?
50 (a)Arrange C,N,O and F in the decreasing order of their second ionization
enthalpy and explain briefly.
(b)Explain why the first ionization enthalpy of Carbon is more than that of
Boron but the reverse is true for second ionization enthalpy
CHAPTER4 CHEMICAL BONDING
Questions based on VSEPR theory, Resonance, Dipole moment, Valence Bond
Theory., hybridization of atomic orbitals
60 (a)Give the main points of VSEPR theory
(b) Discuss the shape using the VSEPR model: H2S, SiCl4, BeF2, CO2 3- , BeCl2,
BCl3, SiCl4, AsF5, H2S, PH3,PCl5, SF6, NH3, SF4, ClF3, BrF5, XeF4, NO361 Although geometries of NH3 and H2O molecules are distorted tetrahedral,
bond angle in water is less than that of ammonia. Discuss.
62 Define Resonance. Explain the structure of CO3 2– ion in terms of resonance.
63. Write the resonance structures for SO3, NO2 and NO3- , CO2
64. Explain the Dipole moment. How it is helpful in predicting polar & Non polar
nature of compounds.
65. Explain why BeH2 molecule has zero dipole moment although the B-H bonds
are polar.
66. Which out of NH3 and NF3 has dipole moment and why?
67. Arrange the bonds in order of increasing ionic character in the molecules:
LiF, K2O, N2, SO2 and ClF3.
68. Explain the formation of Hydrogen molecule on basis of Valence Bond
Theory.
69. (a) Distinguish between a sigma ( ) and a pi ( ) bond
(b)What is the total number of sigma and pi bonds in the following molecules?
(a) C2H2 (b) C2H4.
70. What is meant by hybridization of atomic orbitals?
71. Describe sp,sp2, sp3 hybrid orbitals using suitable examples.
72. Describe the change in hybridization (if any) of the Al atom in the following
reaction: AlCl3 + Cl- AlCl473. Is there any change in the hybridization of B and N atoms as a result of the
following reaction: BF3 + NH3 F3B.NH3
74. Predict the hybrid state of central atom in the following compounds: H2S,
SiCl4, BeF2, CO2 3− , BeCl2, BCl3, SiCl4, AsF5, H2S,
PH3,PCl5,SF6,NH3,SF4,ClF3,BrF5,XeF4.
75. Explain the concept of hybridization in PCl5 .Why are axial bonds longer as
compared to equatorial bonds in PCl5.
76. Which hybrid orbitals are used by carbon atoms in the following molecules?
(a) CH3-CH3 (b) CH3-CH=CH2 (c) CH3-CH2-OH (d)CH3-CHO (e) CH3-COOH
(f) H2C=CH-CH2-CΞCH
Questions based on Atomic orbitals , Molecular orbital configuration
and energy diagram, Bond order & Hydrogen bond
77.Write the molecular orbital configuration and energy diagram for(i)O2
+, O2, O2-, O2 2- (ii)N2,N2 +,N2 - (iii) Be2, H2, C2
78. Draw the energy diagram for H2, Be2, N2,&O2
CHAPTER 5 STATES OF MATTER
Questions based on Intermolecular forces ,Boyle’s Law, Charles’s Law, Gay
Lussac’s Law, Avogadro’s Law
79. A balloon is filled with hydrogen at room temperature. It will burst if
pressure exceeds 0.2 bar. If at 1 bar pressure the gas occupies 2.27 L volume,
up to what volume can the balloon be expanded?
80. What will be the minimum pressure required to compress 500 dm3 of air at 1
bar to 200 dm3 at 30°C?
81. A vessel of 120 mL capacity contains a certain amount of gas at 35 °C and
1.2 bar pressure. The gas is transferred to another vessel of volume 180 mL at
35 °C. What would be its pressure?
Questions based on Ideal gas equation., combined gas law
equation,Dalton’s Law of Partial Pressures
82 Derive Ideal gas equation. Give combined gas law equation.
83 Using the Ideal gas equation Show that the density of the gas is
proportional to the gas pressure p.
84 . Pressure of 1 g of an ideal gas A at 27 °C is found to be 2 bar. When 2 g of
another ideal gas B is introduced in the same flask at same temperature the
pressure becomes 3 bar. Find a relationship between their molecular masses.
640 mL.
85 What will be the pressure exerted by a mixture of 3.2 g of methane and 4.4
g of carbon dioxide contained in a 9 dm3 flask at 27 °C ?
86 Calculate the temperature of 4.0 mol of a gas occupying 5 dm3 at 3.32 bar.
(R = 0.083 bar dm3 K–1 mol–1).
87 Calculate the total pressure in a mixture of 8 g of dioxygen and 4 g of
dihydrogen confined in a vessel of 1 dm3 at 27°C. R = 0.083 bar dm3 K–1 mol–1.
88. Calculate the volume occupied by 8.8 g of CO2 at 31.1°C and 1 bar pressure.
R = 0.083 bar L K–1 mol–1.
89. 2.9 g of a gas at 95 °C occupied the same volume as 0.184 g of dihydrogen
at 17 °C, at the same pressure. What is the molar mass of the gas?
Questions based on Kinetic molecular theory of gases, Vander Waal
modified the ideal gas equation, Surface Tension & Viscosity
90. Critical temperature for CO2 and CH4 are 31.0˚C and – 81.9˚C respectively.
Which of these has stronger intermolecular forces and why?
CHAPTER 6 THERMODYNAMICS
Questions based on system, different types of system
surroundings, First law of thermodynamics, internal energy
91 (a) In a process, 701 J of heat is absorbed by a system and 394 J of work
is done by the system. What is the change in internal energy for the
process?
(b) Calculate the internal energy change when the system absorbs 5 KJ of
heat and 1KJ of work
92 Express the change in internal energy of a system when(i) No heat is
absorbed by the system from the surroundings, but work (w) is done on the
system. What type of wall does the system have?(ii) No work is done on the
system, but q amount of heat is taken out from the system and given to the
surroundings. What type of wall does the system have?(iii) w amount of work
is done by the system and q amount of heat is Supplied to the system. What
type of system would it be?
Questions based on system Enthalpy & its types.
93. The reaction of cyanamide, NH2CN (s), with Dioxygen was carried out in
a bomb calorimeter, and U was found to be -742.7 KJ/mol at 298K.
Calculate :Enthalpy change for the reaction at 298K NH2 CN (s)+3 /2 O2 (g) N2 (g)
+CO 2(g) +H2O(l)
94. Enthalpies of formation of CO (g), CO2 (g), N2O (g) and N2O4 (g) are -110,
-393, 81 and 9.7 KJ/mol respectively. Find the value of rH for the reaction;
N2O4 (g) + 3 CO (g) N2O (g) + 3CO2 (g)
95. Given: N2 (g) + 3H2 (g) 2NH3 (g); rH0 = -92.4 KJ/mol. Calculate f H0NH3
(g).
96 The enthalpy of combustion of methane, graphite and dihydrogen at 298
K are, –890.3 kJ mol–1 –393.5 kJ mol–1, and –285.8 kJ mol–1 respectively.
Calculate the Enthalpy of formation of CH4 (g).
97 For the process to occur under adiabatic conditions, the correct
condition is i) ΔT = 0 (ii) Δp = 0 (iii) q = 0 (iv) w = 0
98 . What is the enthalpies of all elements in their standard states.
99. Enthalpy of combustion of carbon to CO2 is –393.5 kJ mol–1. Calculate the
heat released upon formation of 35.2 g of CO2 from carbon and dioxygen
gas.
100. The combustion of 1 mol of benzene takes place at 298K .After
combustion CO2 and H2O are formed and 3267KJ/mol of heat is liberated
.calculate f H0 (C6H6) Given: f H0 = -286 KJ/mol , f H0 = -393 KJ/mol
101. Calculate the standard enthalpy of formation of CH3OH (l) from the
following data:CH3OH (l) + 3/2 O2 (g) CO2 (g) + 2H2O (l); rH0 = -726
KJ/mol
C (g) + O2 (g) CO2 (g) ; C H0 = -393 KJ/mol
H2 (g) + ½ O2 (g) H2O (l); f H0 = -286 KJ/mol
102Calculate the enthalpy change for the process :
CCl4 (g) C (g) + 4Cl (g) and calculate the bond enthalpy of C-Cl in CCl4 ( g)
vap H0 (CCl4 ) = 30.5 KJ/mol, f H0 (CCl4 ) = -135.5 KJ/mol a H0 (C ) = 715
KJ/mol a H0 (Cl2 ) = 242 KJ/mol
103 (a) Give the relationship between Cp and Cv.
(b)Write a note on Bomb Calorimeter.
104. Explain the following terms with suitable examples: (a) Standard
enthalpy of reaction (b)standard enthalpy of formation (c) enthalpy of
fusion (d) enthalpy of vaporization (e) enthalpy of Sublimation (f) enthalpy
of Combustion (g) enthalpy of Hydration (h) ) enthalpy of Atomization
(i)Bond enthalpy
Questions based on Hess’s law of constant heat summation, Born
Haber cycle,Entropy. Gibbs Energy
105. Predict in which of the following, entropy increases/decreases:
(i) A liquid crystallizes into a solid.
(ii) Temperature of a crystalline solid is raised from 0 K to 115 K.
(iii) 2NaHCO3 (s) →Na2CO3( s)+CO2 (g) + H2O( g)
(iv) H2 (g) →2H(g)
106. Define Gibbs Energy. Give its mathematical expression. What is Gibb‘s
energy criteria of Spontaneity.
107. For the reaction at 298K, 2A + B C, H = 400 KJ/mol and S = 0.2
KJ/mol K At what temperature will the reaction become spontaneous?
108. For the reaction, 2Cl (g) = Cl2 (g), What are the signs of H and S?
109.For the reaction: 2A (g) + B (g) 2D (g), U0 = -10.5 KJ and S0 = 44.1J/K
Calculate G0 for the reaction, and predict whether the reaction will occur
spontaneously.
110. The equilibrium constant for a reaction is 10.Caculate G0, T =300K,
R = 8.314 J/K mol
111. Calculate the value of G0 for the conversion of Oxygen to Ozone,
3/2 O2 (g) O3 (g) at 298 K, if Kp for this conversion is 2.47 × 10-29 .
112. Find out the value of equilibrium constant for the following reaction at
298 K.
2NH3 (g) + CO2 (g) NH2CONH2(aq ) + H2O(l ) Standard Gibbs energy change,
ΔrG0 at\ the given temperature is –13.6 kJ mol–1.
113. Differentiate between the following (with examples)
(a) Intensive and extensive properties
(b) Enthalpy of formation and Enthalpy of reaction.
(c) Enthalpy and Internal energy (d) Heat capacity and specific heat capacity.
(e) Reversible and Irreversible process (f) Adiabatic and Isothermal process.
(g) State function and path function (h) Exothermic and Endothermic reaction.
(i) Isolated, Open, Closed, Adiabatic Systems (j) Heat and Work.
CHAPTER 7 EQUILIBRIUM
Question based on law of chemical equilibrium, Equilibrium constant,
Applications of Equilibrium Constants, Relation Between Kp & Kc.
114. What is Kc for the following equilibrium when the equilibrium
concentration of each substance is: [SO2]= 0.60M, [O2] = 0.82M and [SO3]
= 1.90M 2SO2(g) + O2(g) 2SO3(g)
115. The following concentrations were obtained for the formation of NH3 from
N2 and H2 at equilibrium at 500K. [N2] = 1.5 × 10–2M. [H2] = 3.0 ×10–2 M and [NH3]
= 1.2 ×10–2M. Calculate equilibrium constant.
116. At equilibrium, the concentrations ofN2=3.0 × 10–3M, O2 = 4.2 × 10–3M and
NO= 2.8 × 10–3M in a sealed vessel at800K. What will be Kc for the
reaction:N2(g) + O2(g) 2NO(g)
117. PCl5, PCl3 and Cl2 are at equilibrium at 500 K and having concentration
1.59M PCl3, 1.59M Cl2 and 1.41 M PCl5.Calculate Kc for the reaction,PCl5
PCl3 + Cl2
118. For the equilibrium,2NOCl(g) 2NO(g) + Cl2(g) the value of the
equilibrium constant, Kc is 3.75 × 10–6 at 1069 K.
Calculate the Kp for the reaction at this temperature?
Question based on Calculating Equilibrium Concentrations, Le Chatelierís
principle Effect of Pressure Change, Concentration Change, Temperature
Change, Inert Gas Addition & Catalyst
119. The value of Kc = 4.24 at 800K for the reaction, CO (g) + H2O (g) CO2 (g) +
H2 (g) Calculate equilibrium concentrations of CO2, H2, CO and H2O at 800 K, if
only CO and H2O are present initially at
concentrations of 0.10M each.The value of Kp for the reaction,CO2 (g) + C
(s) 2CO (g) is 3.0 at 1000 K. If initially p CO2= 0.48 bar and p CO = 0
bar and puregraphite is present, calculate theequilibrium partial pressures of
CO and CO2.
120. A sample of pure PCl5 was introduced into an evacuated vessel at 473 K.
After equilibrium was attained, concentration of PCl5 was found to be0.5 ×
10–1 mol L–1. If value of Kc is 8.3 × 10–3, what are the concentrations of
PCl3 and Cl2 at equilibrium?PCl5 (g) PCl3 (g) + Cl2(g)
121. What do you mean by Lechatelier‘s principle? Explain with an example?
122. Dihydrogen gas is obtained from natural gas by partial oxidation with
steam as per following endothermic reaction:
CH4[g] + H2O [g] CO [g] + 3H2[g]
a) Write as expression for Kp for the above reaction.
b) How will the values of Kp and the composition of equilibrium mixture
be affected by
i) Increasing the pressure
ii) Increasing the temperature
iii) Using a catalyst
123. Describe the effect of: - a) Addition of H2 b) Addition of CH3OH c)
Removal of CO d) Removal of CH3OH On the equilibrium of the
reaction: 2 H2[g] + CO[g] CH3OH [g]
REDOX REACTONS
124. BALANCING OF REDOX REACTION BASED ON OXIDISING PROPERTY
OF KMnO4 AND K2Cr2O7 IN ACIDIC MEDIUM. (MINIMUM 15 REACTIONS)
– REFRENCE CLASS 12TH d AND f BLOCK ELEMENTS
125. NOMENCLATURE (MINIMUM 150 EXAMPLES) – REFERENCE : NCERT
12TH CLASS EXERCISE QUESTIONS BASED ON NOMENCLATURE
GENERALLY 1ST AND 2ND