The elements in the periodic table

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FIRST TERM EXAMINATION

ACADEMIC SESSION

SUBJECT: CHEMISTRY

CLASS: S.S.S 2

INSTRUCTION: ANSWER ALL QUESTIONS IN THIS SECTION

1. The elements in the periodic table are arranged in order of their ___________ (a) mass number (b) orbital value (c) atomic number (d) molecular shape
2. Elements in the same group of periodic table have ___________ (a) the same number of valency electron (b) similar electronic configuration (c) the same number of electron (d0 similar orbital configuration
3. S-block elements of the periodic table are made up of ___________ (a) group 1, 2, 3 (b) group 3 and 4 (c) group 7 (d) group 1 and 2
4. In the rediar equation below, the value of x is? (a) 5e^– (b) 10e^– (c) 3e^– (d) 2e^–
5. The bond type in diatomic nitrogen gas is ___________ (a) double covalent bond (b) triple covalent bond (c) single covalent bond (d0 electrovalent bond
6. The flow of current in electrolysis is due to the movement of _________ (a) ions (b) charges (c) electrons (d) light
7. All these properties belong to halogen except _________ (a) they are non – metal (b) they are coloured (c) they exist as diatomic molecule (d0 they do not ionize to form univalent negative ions
8. The type of chemical reaction shown below is _________ (a) hydrolysis (b) neutralization (c) ozonolysis (d0 direct combination
9. Colrosion in iron is called _________ (a) tarnishing (b) electroding (c) rusting (d0 galvanizatin
10. In the activity series of metals, metals higher up will serve as _________(a) cathode (b) anode (c) salt bridge (d) none of the above
11. Electrolyte in the dry lechlanche cell is _________ (a) anhydrous ZnS0₄ (b) NH₄Cl paste (c) mushin bag (d) party Mn0₂
12. Which of the following decrease across the period (a) atomic size (b) electron afirmity (c) electronegativity (d0 inert tendencies
13. The major function of a salt bridge in cell is to _________ (a) smotten the electron flow (b) to provide electrolyte (c) to provide adequate driving force (d) to complete the electric
14. Calculate the mass of aluminium deposited when a current of 3.0 amperes is passing through a aluminium electrodite for 2 hour [Al = 27, 2 Faraday = 96500c] (a) 1.0g (b) 6.04g (c) 2.12g (d) 2.02g
15. One Faraday equal _________ columbs (a) 9650 (b) 96500 (c) 310 (d) 95600
16. What quantity of electricity is consumed when 10 amperes was consumed in 1 hour during electrolysis? (a) 3600 coulombs (b) 7200 coulombs (c) 72 kilo coulombs (d) 36 kilo coulombs
17. From Cl₂ + 2kBr → 2Kcl + Br₂, chlorine is _________ (a) strong reducing agent (b) an aerial (c) strong oxidizing agent (d) an electron donor
18. The oxidation number of manganese in Mno₄^– is _________ (a) +8 (b) -7 (c) +7 (d) -6
19. _________ is the colour of KMn0₄ (a) green (b) purple (c) orange (d) black
20. The IUPAC name of K₂ Cr₂ 0₇ is _________ (a) potassium chromium (ii) (b) potassium heptaoxochromium (v) (c) potassium pentaoxochrominum (vi) (d) potassium dichionate (vi)

THEORY [ANSWER ANY FOUR)

1. What is oxidation and reduction reaction under the following heading (a) addition of oxygen (b) removal of hydrogen (c) addition of electronegative element (c) electron transfer/removal of electron

b. What is oxidation number

2a. state the periodic law

b. Explain the following trends

(i) Ionic size (ii) ionization energy (iii) electron affinity (iv) electronegativity

3. Differentiate the following

(i) Electrovalent and covalent compound

(ii) Electrolytes and non – electrolyte

(iii) Weak and strong electrolyte

(iv) Conductors and non – conductors

b. What is electrolysis

a. Mention and explain the factors affecting preferential discharge of ions

b. State ionic theory

5. Consider the following redox reactions which of the species is

(i) oxidized (ii) the reduction agent (iii) reduced (iv) the oxidizing agent

(a) Cu0_(s) + C0_(g) → Cu + C0₂ (g)

(b) Cr₂ 0₇^2- + Fe²⁺ → Cr³⁺ + Fe³⁺

b. Balance this equations for the reaction occurring in acidic medium using the ion electron method