Name: Assignment - IV Class: X Subject: Chemistry
ALKALINE EARTH METALS
I Choose the correct answer
1. [Ne] 3s2 is the electronic configuration of ( )
(a) Be (b) Mg (c) Ca (d) Sr
2. Valence electronic configuration of alkaline earth elements is ( )
(a) ns2 (b) ns2np6 (c) ns2np3 (d) ns1
3. Which of the following property increases from Be to Ra? ( )
(a) EN (b) IE (c) Atomic size (d) EA
4. Which of the following metal gives peroxide in addition to oxide? ( )
(a) Ba (b) Mg (c) Ca (d) Sr
5. Which of the following metal has highest EN? ( )
(a) Be (b) Mg (c) Ca (d) Ba
6. The MP of IIA group elements from top to bottom ( )
(a) Remains same (b) Increases (c) Decreases (d) Does not show any regular trend
7. The BP of IIA group elements from top to bottom ( )
(a) Remains same (b) Show regular trend (c) Decreases (d) Remains same
8. During electrolytic extraction of Mg, the cathode used is ( )
(a) Iron pot (b) Graphite (c) KCl and NaCl (d) Porcelein tube
9. During electrolytic extraction of Mg, the gas released at anode is ( )
(a) H2 (b) O2 (c) Cl2 (d) No gas is released
II Fill in the blanks
1. The chemical formula of magnesite is ___________________
2. The radioactive element of IIA group elements is _____________________
3. In IIA group elements, the atomic radius from top to bottom ____________________
4. In IIA group, the IE from top to bottom ___________________
5. In IIA group elements the electropositive character from top to bottom _____________
6. In IIA group elements the EN from top to bottom __________________
7. In IIA group elements the variation of MP and BP from top to bottom shows __________________ trend.
8. If IIA group elements are made to react with water (or) HCl (or) H2SO4 _______ gas is released
9. The general chemical formula for the hydrides of alkaline earth elements is _________
10. In the hydrides of IIA group elements, hydrogen carries _____________ charge.
11. Group IIA metals are extracted by the _______________ from their molten chlorides.
12. LiAlH4 acts as _______________ agent.
13. BeH2 is prepared from BeCl2 by using _____________________
14. All the alkaline earth chlorides are ionic except ___________________
15. ______________ gas is released at anode during the extraction of Mg by electrolysis.
16. The _______________ is used as cathode during the extraction of Mg by electrolysis.
17. __________________ and _______________ are added to reduce the MP and MgCl2 during electrolysis.
18. The % purity of Mg obtained by electrolysis is _______________
19. __________________ metal burns with dazzling white light when ignited.
20. Mg3N2 is dissolved in water, it releases ______________ gas.
III 1 Mark questions
1. Why does IE of group IIA elements decrease from Be to Ra?
2. Name three ores of magnesium.
3. Why KCl and Nacl are added to MgCl2 during Mg extraction?
4. Which metals are present in dolomite?
5. How many water molecules are present in Epsom salt?
IV 2 Marks questions
1. What are the electrodes used in the magnesium extraction?
2. Why the MP and BP show irregular trend from Be to Ra?
3. Why alkaline earth metals displace hydrogen form H2O?
4. Write about the method of preparation of BeH2?
5. Write reactions at electrodes during extraction of magnesium.
V 4 Marks questions
1. Write the reactions of group IIA elements with
(i) Oxygen (ii) Hydrogen (iii) Chlorine
2. Describe the method of extraction of Mg from its ore.
VI 5 Marks questions
1. Draw the chart showing the extraction of Mg from its ore
Sep 21, 2008
PERIODIC CLASSIFICATION OF ELEMENTS
Name: Assignment - III Class: X Subject: Chemistry
PERIODIC CLASSIFICATION OF ELEMENTS
I Choose the correct answer
1. In Dobereiner triad, the atomic weight of middle element is ( )
(a) The sum of atomic weights of first and third elements.
(b) The product of the atomic weight of first and third elements.
(c) The ratio of the atomic weights of first and third elements.
(d) The mean of the atomic weights of first and third elements.
2. The first classification of elements is attempted by ( )
(a) Bohr (b) Mosley (c) Mendeleef (d) Dobereiner.
3. The number of columns present in modern periodic table. ( )
(a) 15 (b) 16 (c) 17 (d) 18
4. Mendeleef’s periodic table is based on ( )
(a) Atomic volume (b) Atomic radius (c) Atomic weight (d) Atomic number
5. Mosley’s periodic table is based on ( )
(a) Atomic volume (b) Atomic radius (c) Atomic weight (d) Atomic number
6. The number of elements present in the first period are ( )
(a) 8 (b) 2 (c) 18 (d) 36
7. The incomplete period is ( )
(a) 7 (b) 6 (c) 1 (d) 2
8. The ionization potential in a group from top to bottom ( )
(a) Decreases (b) Increases (c) Remains same (d) Shows irregular trend
9. The atomic radius is measured in ( )
(a) eV (b) kJ/mole (c) kcal/mole (d) Angstrom
II Fill in the blanks
1. The earliest classification of elements is due to _____________________ in 1817.
2. Law of octaves was proposed by _____________________
3. Lother Meyer, proposed the periodic law based on the _______________ of elements.
4. Mendeleef arranged the elements in the increasing order of their _________________
5. The periodic table proposed by Mosley is known as _______________________
6. Mosley’s periodic law states that ‘the properties of the elements are the periodic function of their _____________________.
7. The chemical similarity of elements in a group is due to their similar _____________ electronic configuration.
8. Each period starts with ________________ and ends with ______________ elements.
9. Inert gases are the elements having _________________ electronic configuration.
10. Elements of s-block and p-block put together are known as ____________________
11. All types of elements, viz., metals, metalloids, non metals are placed in ________________
12. In a group the atomic radius ______________ from top to bottom.
13. In a group the EN __________________ from top to bottom.
14. EN of inert gases is __________________
15. The oxidizing power in a group _______________ and in a period _______________
16. The reducing power in a group _______________ and in a period________________
III 1 Mark questions
1. What is a triad?
A. A set of three elements arranged in the increasing order of their atomic weights is called a triad.
2. Give examples of three Dobereiner triads.
A. Cl, Br, I; S, Se, Te,; Li, Na, K; Fe, Co, Ni are the different triads arranged by Dobereiner.
3. What is Newland’s concept of octaves?
A. According to law of octaves, if the elements are arranged in the increasing order of their atomic weights, the properties of eight elements is a kind of repetition of the first one like the 8th note of an octave in music.
4. State Mendeleef’s periodic law.
A. Mendeleef’s periodic law states that ‘the properties of the elements are the periodic function of their atomic weights’.
5. Name the inert gases.
A. He, Ne, Ar, Kr, Xe, Rn are the inert gas elements.
6. Write the general electronic configuration of inert gases.
A. ns2, np6 is the general electronic configuration of inert gases.
7. What are inner transition elements?
A. Lanthanides and actinides (f-block elements) are called inner transition elements.
8. Define atomic radius.
A. The distance between the centre of the nucleus and the outermost oribital is defined as atomic radius (or) atomic size.
9. Define second ionization energy.
A. The minimum energy required to remove an electron from the outermost orbital of unipositive ion is defined as second ionization energy.
10. Define electronegativity
A. The tendency of a bonded atom in a molecule to attract the electron density of the shared pair of electrons is called as electronegativity
11. Define electropositive character
A. The tendency (or ability) of an atom to lose the valence electrons and become +vely charged ion is called electropositive character (or) metallic character.
12. Which group of the elements have highest electropositive character?
A. IA group elements have highest electropositive character.
13. Define oxidation and reduction.
A. Oxidation: Addition of oxygen to a given compound (or) removal of hydrogen from a given compound is called oxidation.
Reduction: Addition of hydrogen to a given compound (or) removal of oxygen from a given compound is defined as reduction.
14. Which group of elements can be used as oxidizing and reducing agents?
A. Oxidizing agents: VII A group-elements can be used as oxidizing agents.
Reducing agents: IA and IIA group elements can be used as reducing agents.
IV 4 Marks questions
1. How does the atomic radius vary in a period and in a group?
2. Explain the variation of ionization energy in a group?
3. Write about the salient features and draw backs of Mendeleef’s periodic table.
4. What re the features of long form of periodic table? (or) what are the salient features of Mosley’s periodic table?
PERIODIC CLASSIFICATION OF ELEMENTS
I Choose the correct answer
1. In Dobereiner triad, the atomic weight of middle element is ( )
(a) The sum of atomic weights of first and third elements.
(b) The product of the atomic weight of first and third elements.
(c) The ratio of the atomic weights of first and third elements.
(d) The mean of the atomic weights of first and third elements.
2. The first classification of elements is attempted by ( )
(a) Bohr (b) Mosley (c) Mendeleef (d) Dobereiner.
3. The number of columns present in modern periodic table. ( )
(a) 15 (b) 16 (c) 17 (d) 18
4. Mendeleef’s periodic table is based on ( )
(a) Atomic volume (b) Atomic radius (c) Atomic weight (d) Atomic number
5. Mosley’s periodic table is based on ( )
(a) Atomic volume (b) Atomic radius (c) Atomic weight (d) Atomic number
6. The number of elements present in the first period are ( )
(a) 8 (b) 2 (c) 18 (d) 36
7. The incomplete period is ( )
(a) 7 (b) 6 (c) 1 (d) 2
8. The ionization potential in a group from top to bottom ( )
(a) Decreases (b) Increases (c) Remains same (d) Shows irregular trend
9. The atomic radius is measured in ( )
(a) eV (b) kJ/mole (c) kcal/mole (d) Angstrom
II Fill in the blanks
1. The earliest classification of elements is due to _____________________ in 1817.
2. Law of octaves was proposed by _____________________
3. Lother Meyer, proposed the periodic law based on the _______________ of elements.
4. Mendeleef arranged the elements in the increasing order of their _________________
5. The periodic table proposed by Mosley is known as _______________________
6. Mosley’s periodic law states that ‘the properties of the elements are the periodic function of their _____________________.
7. The chemical similarity of elements in a group is due to their similar _____________ electronic configuration.
8. Each period starts with ________________ and ends with ______________ elements.
9. Inert gases are the elements having _________________ electronic configuration.
10. Elements of s-block and p-block put together are known as ____________________
11. All types of elements, viz., metals, metalloids, non metals are placed in ________________
12. In a group the atomic radius ______________ from top to bottom.
13. In a group the EN __________________ from top to bottom.
14. EN of inert gases is __________________
15. The oxidizing power in a group _______________ and in a period _______________
16. The reducing power in a group _______________ and in a period________________
III 1 Mark questions
1. What is a triad?
A. A set of three elements arranged in the increasing order of their atomic weights is called a triad.
2. Give examples of three Dobereiner triads.
A. Cl, Br, I; S, Se, Te,; Li, Na, K; Fe, Co, Ni are the different triads arranged by Dobereiner.
3. What is Newland’s concept of octaves?
A. According to law of octaves, if the elements are arranged in the increasing order of their atomic weights, the properties of eight elements is a kind of repetition of the first one like the 8th note of an octave in music.
4. State Mendeleef’s periodic law.
A. Mendeleef’s periodic law states that ‘the properties of the elements are the periodic function of their atomic weights’.
5. Name the inert gases.
A. He, Ne, Ar, Kr, Xe, Rn are the inert gas elements.
6. Write the general electronic configuration of inert gases.
A. ns2, np6 is the general electronic configuration of inert gases.
7. What are inner transition elements?
A. Lanthanides and actinides (f-block elements) are called inner transition elements.
8. Define atomic radius.
A. The distance between the centre of the nucleus and the outermost oribital is defined as atomic radius (or) atomic size.
9. Define second ionization energy.
A. The minimum energy required to remove an electron from the outermost orbital of unipositive ion is defined as second ionization energy.
10. Define electronegativity
A. The tendency of a bonded atom in a molecule to attract the electron density of the shared pair of electrons is called as electronegativity
11. Define electropositive character
A. The tendency (or ability) of an atom to lose the valence electrons and become +vely charged ion is called electropositive character (or) metallic character.
12. Which group of the elements have highest electropositive character?
A. IA group elements have highest electropositive character.
13. Define oxidation and reduction.
A. Oxidation: Addition of oxygen to a given compound (or) removal of hydrogen from a given compound is called oxidation.
Reduction: Addition of hydrogen to a given compound (or) removal of oxygen from a given compound is defined as reduction.
14. Which group of elements can be used as oxidizing and reducing agents?
A. Oxidizing agents: VII A group-elements can be used as oxidizing agents.
Reducing agents: IA and IIA group elements can be used as reducing agents.
IV 4 Marks questions
1. How does the atomic radius vary in a period and in a group?
2. Explain the variation of ionization energy in a group?
3. Write about the salient features and draw backs of Mendeleef’s periodic table.
4. What re the features of long form of periodic table? (or) what are the salient features of Mosley’s periodic table?
CHEMICAL BOND
Name: Assignment - II Class: X Subject: Chemistry
CHEMICAL BOND
I Choose the correct answer
1. Octet configuration means ( )
(a) Having 6 valence electrons (b) Having 4 valence electrons
(c) Having 8 valence electrons (d) Having 2 valence electrons
2. At critical inter nuclear distance, the potential energy of the combining atoms is ( )
(a) Minimum (b) Maximum (c) It does not change
(d) Some times it is minimum and some times it is maximum.
3. Complete transfer of electrons from one atom to another leads to the formation of ( )
(a) Covalent bond (b) Polar covalent bond (c) Ionic Bond (d) None
4. Polar covalent bond is present in ( )
(a) Cl2 (b) H2 (c) F2 (d) HCl
5. Sharing of electrons lead to the formation of ( )
(a) Ionic bond (b) Covalent bond (c) Hydrogen bond (d) Metallic bond
6. If two pairs of electrons are shared between two atoms, that bond is called ( )
(a) Ionic bond (b) Co-ordinate covalent bond (c) Double bond
(d) Triple bond
7. If both the shared pair of electrons are contributed by only one atom it is called ( )
(a) Ionic bond (b) Covalent bond (c) Polar covalent bond (d) Co-ordinate covalent bond
8. Shape of H2O is ( )
(a) ‘V’ Shape (b) Pyramidal (c) Linear (d) Tetrahedral
9. Shape NH3 is ( )
(a) Linear (b) ‘V’ Shape (c) Tetrahedral (d) Pyramidal
10. Shape of PCl2 is ( )
(a) Linear (b) Trigonal bipyramidal (c) Tetrahedral (d) Pyramidal
11. Shape of BeCl2 is ( )
(a) Tetrahedral (b) Pyramidal (c) Linear (d) ‘V’ Shape
12. s-p overlap is present in ( )
(a) HCl (b) O2 (c) Cl2 (d) H2
13. p-p overlap is present in ( )
(a) HCl (b) Cl2 (c) BeCl2 (d) NH2
14. Triple bond is present in ( )
(a) Cl2 (b) H2 (c) CaCl2 (d) CaC2
15. The essential condition for the overlap of orbitals is that ( )
(a) They must be completely filled orbitals
(b) They must be only ‘s’ orbitals
(c) They must be half filled valence orbitals
(d) They must be only ‘p’ orbitals.
II Fill in the blanks
1. s-s overlap always leads to the formation of __________________ bond
2. End – on – end overlap of two orbitals always leads to the formation of ___________ bond
3. Side – on – side overlap of orbitals leads to the formation of _________________ bond
4. - bond can exist ___________________
5. - bond can’t exist ____________________
6. C2H2 has ___________________ bonds and __________________ bonds
7. N2 has _____________________ and _____________________ bonds
8. Oxygen has __________________ lone pairs of electrons in H2O molecule.
9. Nitrogen has __________________ lone pair of electrons in NH3 molecule.
10. ________________ atom is donor in (H3O)+
11. ________________ is acceptor in NH3.BF3
III 1 Mark questions
1. Name a molecule having s-s overlap.
A. Hydrogen
2. Name molecules having s-p overlap
A. HCl, H2O, NH3, HBr, HI, H2S
3. Name three molecules having p-p overlap
A. Cl2, O2, N2, Br2
4. Which orbitals can form ‘’ bond?
A. Side – on – side overlap of p-p orbitals can form bond. [s orbitals are never involved in the formation of bond]
5. Which orbitals can form bond?
A. Overlap of s-s orbitals, end-on-end overlap of s-p, or p-p orbitals can form bond.
6. Name the molecules that are linear in shape.
A. CO2, BeCl2 and HCN molecules have linear shape.
7. Name the molecules that have pyramidal shape.
A. Ammonia (NH3), Phosphorus trichloride (PCl3) and phosphine (PH3) have pyramidal shape.
8. Which molecules have triple bonds?
A. Acetylene (C2H2), Nitrogen (N2), Calcium Carbide (CaC2), Hydrogen Cyanide (HCN) have triple bonds.
9. Which molecules have double bonds in them?
A. Carbon dioxide (CO2), Oxygen (O2) and Ethylene (C2H4) have double bonds.
10. Which molecules have co-ordinate covalent bond?
A. Ammonia boron trifluoride (NH3BF3), Ammonium ion (NH4+), Hydronium ion (H3O+), Hexa hydrate iron (II) ion [Fe(H2O)6+2], Hexahydrate copper (II) ion [Cu(H2O)6]+2
IV 2 Marks questions
1. Explain how covalent bond is formed?
2. Explain the formation of HCl molecule by overlapping of orbitals?
3. Explain the formation of HCl molecule by electron dot formula?
V 4 Marks questions
1. Discuss the types of overlaps that are possible with s and p orbitals?
2. Explain the formation of a double bond.
3. Explain the formation of a triple bond.
4. Explain the formation of co-ordinate covalent bond.
VI 5 marks questions
1. Draw the neat diagrams how sigma and pi bonds are formed.
2. Draw the shapes of H2O, NH3 and PCl5
CHEMICAL BOND
I Choose the correct answer
1. Octet configuration means ( )
(a) Having 6 valence electrons (b) Having 4 valence electrons
(c) Having 8 valence electrons (d) Having 2 valence electrons
2. At critical inter nuclear distance, the potential energy of the combining atoms is ( )
(a) Minimum (b) Maximum (c) It does not change
(d) Some times it is minimum and some times it is maximum.
3. Complete transfer of electrons from one atom to another leads to the formation of ( )
(a) Covalent bond (b) Polar covalent bond (c) Ionic Bond (d) None
4. Polar covalent bond is present in ( )
(a) Cl2 (b) H2 (c) F2 (d) HCl
5. Sharing of electrons lead to the formation of ( )
(a) Ionic bond (b) Covalent bond (c) Hydrogen bond (d) Metallic bond
6. If two pairs of electrons are shared between two atoms, that bond is called ( )
(a) Ionic bond (b) Co-ordinate covalent bond (c) Double bond
(d) Triple bond
7. If both the shared pair of electrons are contributed by only one atom it is called ( )
(a) Ionic bond (b) Covalent bond (c) Polar covalent bond (d) Co-ordinate covalent bond
8. Shape of H2O is ( )
(a) ‘V’ Shape (b) Pyramidal (c) Linear (d) Tetrahedral
9. Shape NH3 is ( )
(a) Linear (b) ‘V’ Shape (c) Tetrahedral (d) Pyramidal
10. Shape of PCl2 is ( )
(a) Linear (b) Trigonal bipyramidal (c) Tetrahedral (d) Pyramidal
11. Shape of BeCl2 is ( )
(a) Tetrahedral (b) Pyramidal (c) Linear (d) ‘V’ Shape
12. s-p overlap is present in ( )
(a) HCl (b) O2 (c) Cl2 (d) H2
13. p-p overlap is present in ( )
(a) HCl (b) Cl2 (c) BeCl2 (d) NH2
14. Triple bond is present in ( )
(a) Cl2 (b) H2 (c) CaCl2 (d) CaC2
15. The essential condition for the overlap of orbitals is that ( )
(a) They must be completely filled orbitals
(b) They must be only ‘s’ orbitals
(c) They must be half filled valence orbitals
(d) They must be only ‘p’ orbitals.
II Fill in the blanks
1. s-s overlap always leads to the formation of __________________ bond
2. End – on – end overlap of two orbitals always leads to the formation of ___________ bond
3. Side – on – side overlap of orbitals leads to the formation of _________________ bond
4. - bond can exist ___________________
5. - bond can’t exist ____________________
6. C2H2 has ___________________ bonds and __________________ bonds
7. N2 has _____________________ and _____________________ bonds
8. Oxygen has __________________ lone pairs of electrons in H2O molecule.
9. Nitrogen has __________________ lone pair of electrons in NH3 molecule.
10. ________________ atom is donor in (H3O)+
11. ________________ is acceptor in NH3.BF3
III 1 Mark questions
1. Name a molecule having s-s overlap.
A. Hydrogen
2. Name molecules having s-p overlap
A. HCl, H2O, NH3, HBr, HI, H2S
3. Name three molecules having p-p overlap
A. Cl2, O2, N2, Br2
4. Which orbitals can form ‘’ bond?
A. Side – on – side overlap of p-p orbitals can form bond. [s orbitals are never involved in the formation of bond]
5. Which orbitals can form bond?
A. Overlap of s-s orbitals, end-on-end overlap of s-p, or p-p orbitals can form bond.
6. Name the molecules that are linear in shape.
A. CO2, BeCl2 and HCN molecules have linear shape.
7. Name the molecules that have pyramidal shape.
A. Ammonia (NH3), Phosphorus trichloride (PCl3) and phosphine (PH3) have pyramidal shape.
8. Which molecules have triple bonds?
A. Acetylene (C2H2), Nitrogen (N2), Calcium Carbide (CaC2), Hydrogen Cyanide (HCN) have triple bonds.
9. Which molecules have double bonds in them?
A. Carbon dioxide (CO2), Oxygen (O2) and Ethylene (C2H4) have double bonds.
10. Which molecules have co-ordinate covalent bond?
A. Ammonia boron trifluoride (NH3BF3), Ammonium ion (NH4+), Hydronium ion (H3O+), Hexa hydrate iron (II) ion [Fe(H2O)6+2], Hexahydrate copper (II) ion [Cu(H2O)6]+2
IV 2 Marks questions
1. Explain how covalent bond is formed?
2. Explain the formation of HCl molecule by overlapping of orbitals?
3. Explain the formation of HCl molecule by electron dot formula?
V 4 Marks questions
1. Discuss the types of overlaps that are possible with s and p orbitals?
2. Explain the formation of a double bond.
3. Explain the formation of a triple bond.
4. Explain the formation of co-ordinate covalent bond.
VI 5 marks questions
1. Draw the neat diagrams how sigma and pi bonds are formed.
2. Draw the shapes of H2O, NH3 and PCl5
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