CBSE Class 11 Chemistry Revision Assignment

Q . 1. What is the number of significant figure in 2.3098?

Q. 2. Calculate the No. of σ and π  bonds in CaC₂..

Q. 3. What are the conditions necessary for a gas to behave ideal?

Q. 4. Why water has bent shaped and ammonia has trigonal pyramidal in spite of same hybridization in case of both?

Q. 5. What will be the number of orbitals if the Principal Quantam Number is 4?

Q. 6. Why Chlorine has greater electron gain enthalpy than Fluorine?

Q. 7. Why water is liquid but hydrogen sulfide is a gas?

Q. 8. Calculate the number of molecules and atoms in:

i. 2 moles of Water

ii. 3 moles of ammonia

Q1) Write hybridization of central atom of the following species.

a) NH₄⁺    b) H₃O⁺   c) PCl ₅  d) SO₄^2-   e) I₃^-

Q2) Which has higher dipole moment CH₃F or CH₃Cl?

Q3) What is the effect of temperature and pressure on the following properties of liquid .

a) surface tension b) viscosity

Q4) Balance the following redox reaction as per the given instruction :

i) Cr₂O₇^2- + SO₂ + H⁺ ----→ Cr³⁺ + HSO₄^- + H₂O ( by ion electron method)

ii) MnO₄ ^-(aq) + Br^-(aq)----→ MnO₂ (s) + BrO₃^- (aq) (by ion electron method in basic medium)

Q5) Give reasons:

a) In PCl₅ why are axial bonds are longer than equatorial bonds?

b) Why dipole moment of NH₃ is more than NF₃? Why dipole moment of NH₃ is more than NF₃?

1. State law of multiple proportion . Explain it with the help of example.

2. 0.7 g Fe combines with 0.4 g of S to formFeS. 2.8g of Fe dissolved in HCl Precipitates out 4.4g FeSon treatment with Na₂s. Prove that it obeys law of constant proportion.

3. Calculate the total number of electrons in 1.6g of methane .

4. From 200mg of CO₂,10²¹molecules are removed. How many mg and moles of CO₂ are left ?

5. The %age composition of F.A.S is 14.32% Fe²⁺, 9.20% NH₄⁺, 49.0% SO₄²-and 27.57% H₂O. What is the empirical formule of the compound [F.A.S is ferrous ammonium sulphate]

6. 2.0g of Mg is burnt in 1.0g of 0₂ Which is the limiting reagent ? What is the amount of MgOformed ?

7. The density of 3M solution of NaCl is 1.25g/ml. Calculate molality of solution.

8. What information regarding quantum nos. is given by 3d⁷ ?

9. The ionization energy oh H atom is 13.6 eV . What will be the ionization energy of He⁺and li²⁺ ?

10. Calculate the momentum of of a particle which has a de Brogle’s wavelength of 10^-10m.

11. The uncertainity in position and velocity of a particle are 10-10m and 5.27 X 10-24ms-1respectively.Calculate the mass of the particle?

1. Make a project on the following topics given below. It should include

• Principle

• Explanation

• Graphical data

• Mathematical formulations

• Real life applications

Topics are:

a. Photoelectric effect

b. Black Body Radiation Effect

c. Indicators

d. Buffers

e. Titrations (volumetric , gravimetric, conductometric)

2. Solve the worksheet of numerical given :

1. Calculate the wavelength of an electron moving with velocity of 2.05*10⁷ms^{- 1}?

2. Calculate number of each type in 5.3g of Na₂Co₃?

3. An oxide of manganese was found to cantain 69.64%Mn.what is the simplest formula of an oxide?

4. Determine the empirical formula of an compound having the percentage composition Fe =20% S=11.5 % O=23.1% and H₂O=20.35% ?

General Instructions:
• All questions are compulsory.
• Mark for each question is indicated against it.

1. Define
Wavelength
ii. Frequency

2. State Avogadro law 

3. Explain law of multiple proportion with suitable example 

4. Distinguish between Molarity and molality? 

5. Calculate the mass of
a. One molecule of NH₃ b. 44.8 L of CO₂
(RAM of O = 16u, C= 12 u , H=1 u , N=14 u )

6. a. Distinguish between quantum and photon
b. Define Threshold energy.

7 4.8g of O₂ was used to burn 0.15moles of Fe to Fe₂O₃.
a. Which is the limiting reagent?
b. What mass of Fe₂O₃ was formed?
c. Calculate the mass of excess reagent left? (RAM of Fe = 56u )

8 A compound contains 4.07 % hydrogen, 24.27 % carbon and 71.65 % chlorine. Its molar
mass is 98.96 g. Deduce its empirical and molecular formula.
(RAM of H= 1 u ,O=16 u, Cl =35.5 u )

9 a. Explain the dual nature of electromagnetic radiation.
b. Electromagnetic radiation of wavelength 242 nm is just sufficient to ionise the sodium atom. Calculate the energy of electromagnetic radiation in kJ/ mol.
(h = 6.63 x10^-34Js)

10 a. Define Photoelectric effect.
b. Electrons are emitted with zero velocity from a metal surface when it is exposed to radiation of wavelength 6800Ao.Calculate the threshold frequency and work function of the metal.

11 Commercially available H₂SO₄ contains 98% acid by mass. Find the molarity if density of the sample is 1.84g/cc. What volume of this acid is required to make 2 L of 0.1 M solution?

General Instructions:
• All questions are compulsory.
• Mark for each question is indicated against it.

1. State Gay Lussac’s law of gaseous volumes. 

2. Name the nature of electromagnetic radiation that explains the following types of experimental phenomenon shown by it:
a. Interference.
b. Photoelectric emission.

3. Explain law of definite proportion with suitable example. 

4. Distinguish between empirical formula and molecular formula. 

5. Calculate the mass of
a. One molecule of C₆H₆ b. 33.6 L of CO₂
(RAM of O = 16u, C = 12 u , H =1 u )

6. a. Distinguish between quantum and photon.
b. Define
i. Wave number ii. Velocity

7. a. Calculate the mole fraction of ethanol in 0.5 m aqueous solution of ethanol.
b. 4 L of water is added to 2L of 6 molar HCl solution.What is the molarity of resulting solution?

8. 4.8g of O₂ was used to burn 0.15moles of Fe to Fe₂O_3.
a. Which is the limiting reagent?
b. What mass of Fe₂O₃ was formed?
c. Calculate the mass of excess reagent left? (RAM of Fe= 56u )

9. a. Define Photoelectric effect.
b. Electrons are emitted with zero velocity from a metal surface when it is exposed to radiation of wavelength 6800A^o.Calculate the threshold frequency and work function of the metal.

10. An organic compound containing carbon, hydrogen and oxygen gave the following composition C: 40.68%, H: 5.08%.The vapour density of the compound is 59. Calculate its molecular formula. (Given: RAM of C = 12, H = 1 & O = 16)

11. a. Define workfunction.
b. A photon of wavelength 4 × 1 0^–7 m strikes on metal surface, Calculate the energy of the photon in eV.
(h = 6.63 x10^-34Js,1 eV= 1.6020 × 10^–19J).

1. State Avogadro law.

2. Define

i. Wavelength

ii. Frequency

3. Write short note on Planck’s quantum theory.

4. Explain law of multiple proportion with suitable example

5. a. 1L of a gas at STP weighs 1.97g. What is its molar mass?

b. Calculate the mass percentage of Sulphur in H₂SO₄(RAM of S= 32u )

6. a. What do you mean by mole fraction?

b. Define Threshold energy.

7. 6.5g of Zn was reacted with excess of dil. HCl. Calculate

a. the amount and volume of hydrogen produced at STP.

b. The amount of HCl consumed.

(RAM of Zn = 65u,Cl = 35.5 u )

8.  A compound contains 4.07 % hydrogen, 24.27 % carbon and 71.65 % chlorine. Its molar mass is 98.96g. Deduce its empirical and molecular formula. (RAM of H= 1 u ,O = 16 u )

9. A photon of wavelength 4.0x10^-7m strikes on metal surface, the work function of the metal
being 2.13eV. Calculate
a. Energy of photon (eV)
b. The kinetic energy of the emission and
c. The velocity of the photoelectron emitted.
(1eV =1.602 x 10^-19J, me= 9.1 x10^-31 Kg)

10 Commercially available H₂SO₄ contains 98% acid by mass. Find the molarity if density of
the sample is 1.84g/cc. What volume of this acid is required to make 2 L of 0.1 M solution?

11 a. Explain the dual nature of electromagnetic radiation.
b. Electromagnetic radiation of wavelength 242 nm is just sufficient to ionise the sodium atom. Calculate the energy of electromagnetic radiation in kJ/ mol. (h = 6.63 x10^-34Js)

QUESTIONS:

Q1. Which Quantum number tends to specify the orientation in space for an orbital?

Q2. Is CaF₂ linear or bent or neither of the two? Justify.

Q3. Melting point of MgO is greater than NaCl. Why?

Q4. What is the basic idea of VSEPR theory?

Q5. Predict which of the following molecules have higher dipole moment and why? CS₂ or OCS

Q6. Which type of bond is present in HCl?

Q7. Define normality.

Q8. The first excited state refers to the electronic configuration with an energy closest to but higher than that of ground state. Write electronic configuration of the first excited state of

(i) Carbon

(ii) Nitrogen

Q9. What are paramagnetic and diamagnetic substances?

Q10. Write electronic configurations of the following species: Cr and Cu
(Atomic numbers of Cr and Cu are 24 and 29 respectively)

Q11. Draw the orbital diagram of ethylene on the basis of hybridization involved.

Q12. What is Photoelectric effect? Which factors determine the energy and number of electrons in this phenomenon?

Q13 What do you mean by hardness of water? What are its types? How can we remove it?

Q14 Write elements of the second period of the periodic table and identify the one
(i) With largest atomic size
(ii) With smallest atomic size
(iii) With lowest ionization enthalpy
(iv) With highest electron gain enthalpy.

Q15 Give reasons:
(i) AlBr₃ is a poor conductor of electricity in molten state.
(ii) The solution of alkali metals in liquid ammonia is blue in colour.

Q16 Explain (i) common ion effect (ii) buffer solution.

Q17 In astronomical observations, signals observed from the distant stars are generally weak. If the photon detector receives a total of 3.15X10-18J from the radiation of 600nm, calculate the number of photons received by the detector.

Q18 What is atomic radius? What are its different types? Define each. Which one of them is largest and why?

Q19 What is Ionisation enthalpy? What are the factors which affect ionization enthalpy?

Q20 Give reasons
(i) Ionisation enthalpy of Boron is found to be lower than Beryllium which is against the trend.
(ii) Second electron gain enthalpy of oxygen is positive
(iii) Electron affinity of fluorine is lower than that of chlorine.

Q21 Write short note on the following:. (i) Markovnikovs rule (ii) peroxide effect (iii) Wurtz reaction.

Q22 Can an ionic compound behaves like a covalent compound? If yes, then what are the conditions? Explain.

Q24 The concentration of cholesterol (C₂₂H₄₆O) in normal blood is approximately 0.005 M. How many grams of cholesterol are in 750 ml of blood?

Q25 A compound contains 4.07% hydrogen, 24.27% carbon and 71.65% chlorine. Its molar mass is 98.96g. What are its empirical and molecular formulas?

Q26 Ammonia gas is prepared by warming solid ammonium chloride with aqueous sodium hydroxide solution. NH₄Cl + NaOH ®NH₃(g) + H₂O(l) + NaCl (aq)
(i) How many grams of NH₄Cl are required for every 30 g NaOH used up?
(ii) How many moles of NaCl will be formed?
(iii) How many grams of ammonia will be evolved?

Q27 (a) Write at least four differences between orbit and orbital.
(b) Write the values of all the four quantum numbers for the orbital 5f.
(c) What is spectrum? Explain one of its types.
                     OR
(a) Write short notes on
(i) Quantum numbers (ii) Bohr’s Model
(b) Define isotones and give examples.

Q28 (a) Write four properties of d block elements.
(b) What is electro negativity? How it changes in a period and in a group?
(c) What is electron gain enthalpy?
                            OR
(i) What transition in the hydrogen spectrum would have the same wavelength as the Balmer transition n=4 to n = 2 of He⁺?
(ii) Explain why Mg²⁺ is smaller than O^2- although both have same electronic configuration.
(iii) What are f block elements?
(iv) Predict the period and group of the element with atomic number 54.

Q29 (a) What is Hybridisation? Explain the shape of ammonia molecule.
(b) Write any four differences between sigma and pi bonds?
                                        OR
(a) What is the basic idea of molecular Orbital Theory? Predict the bond order of the following species on the basis of molecular orbital theory.
N₂, N₂⁺, N₂^-
(b) Predict the shapes of the following compounds on the basis of VSEPR theory:
(i) SF₄ (ii) H₂O

Q30 i) Why does benzene undergo electrophillic substitution easily and nucleophillic substitution with difficulty?
ii) Complete the followings:
a) CH₃COOH + NaOH →
b) CH₃CH = CHCH₃ → (Ozonolysis and hydrolysis in presence of Zn)
c) C₆H₆ +Cl₂→  (in presence of sunlight)