Multiple Choice Question For Practice: 4. Periodic table:

4. Periodic table:

1. The first attempt to classify elements was made by 

    a) Mendeleev                b) Neslands

    c) Lother Meyer            d) Dobereiner

2. In the modern periodic table the elements are

  arranged in

    a) increasing mass       

    b) increasing atomic volume

    c) increasing atomic number

    d) alphabetically   

  

3. Which of the following sets belong to the same

  period?

    a) Li, Na, K                      b) Li, Mg, Ca

    c) Ni, Cu, Zn                   d)F, Cl, Br  

 

4. Which of the following is the largest in size?

    a) Cl^-                                 b) S^2-

    c) Na⁺                               d) F^-  

5. If the valence shell electronic structure is ns² np⁵, the

  element will belongs to the group of

    a) alkali metals                 b) halogens

    c) alkaline earth metals  d) actinides  

 

6. Which of the atomic no. represents s-block elements

    a) 7, 15                             b) 3, 12

    c) 6, 12                             d) 9, 17

7. Which pair of elements has similar properties

    a) 13, 31                          b) 11, 20

    c) 12, 10                          d) 21, 33  

8. In the long form of periodic table the total number

  of periods is

    a) 5                                   b) 7

    c) 8                                   d) 9  

9. The lanthanides are placed in the periodic table at

    a) left hand side             b) right hand side

    c) middle                         d) bottom  

   

10. In long form of periodic table the number of groups

     are

    a) 15                                  b) 18

    c) 12                                  d) 8   

11. Actinides belongs to following type of elements.

    a) s-block elements        b) d-block elements

    c) f-block elements        d) p-block elements 

12. Halogens are placed in which group of elements in

    modern periodic table.

    a) 17                                 b) 2

    c) 4                                   d) 5   

5.Redox Reaction:

1. Oxidation number of P is +3 in the compound

    a) H₃PO₂                         b) H₃PO₃

    c) H₃PO₄                         d) H₄P₂O₇    

2. A substance that gains electron is

    a) an oxidizing agent   

    b) a reducing agent  

    c) a substance that oxidizes                         

    d) reductant

3. A substance that goes to higher oxidation state

   (number) is

    a) an oxidizing agent    b) a substance that reduces

    c) a reducing agent      d) oxidant     

4. Oxidation number of Cl in KClO₃ is

    a) -1                                 b) -5

    c) +1                                d) +5  

5.The sum of oxidation states of all atoms in ClO₄^- ion is

    a) zero                             b) -4

    c) -1                                 d) +2   

6. In the reaction A + B⁺        →       A⁺  +  B, A is  

    a) oxidized

    b) reduced

    c) an oxidized agent      

    d) that lowers its oxidation number  

7. The unbalanced half equation,

     CrO₄^2-_(aq)      →          Cr(OH)₄^-_(aq)  is

    a) an oxidation

    b) a redox reaction

    c) a reduction

    d) an electron transfer equation  

8. The oxidation number if I in HOI is

    a) -1                                  b) 0

    c) -2                                  d) +1 

9. Oxidation number if H in AlH₃ is 

    a) +1                                 b) -1

    c) +3                                 d) zero   

10. Oxidation number of oxygen in O₂^2- ion is

    a) -2                                  b) +1

    c) -1                                  d) +2    

6. Chemical equilibrium:

1. The chemical equilibrium is the state of chemical reaction at which ……

    a) rate of forward reaction is greater than the rate of
        backward reaction

    b) rate of forward reaction is less than the rate of
        backward reaction

    c) rate of forward reaction is equal to the rate of
        backward reaction 

    d) rate of forward and backward reactions are not

         related to each other.   

2. The relation between K_c and K_p for the reaction,

     A_(g)  +  B_(g)    → C_(g)  +  2D_(g) is

    a) K_c =                        b) K_p = K_c²

    c) K_c =                       d)  = 1

3. When volume of the equilibrium reaction,

C_(s)  +  H₂O →    CO_(g)  +  H_2(g)  is increased at constant temperature, the equilibrium will    

    a) shift from left to right

    b) shift from right to left 

    c) be unaffected

    d) not be predicted

4. For the equilibrium Cl_2(g)  + 2NO_(g)  →2NOCl_(g), the concentration of NOCl will increase if the equilibrium is disturbed by

    a) adding Cl₂                  b) removing NO

    c) adding NOCl              d) removal of Cl₂

5. For the equilibrium, A 2B  + Heat, the number of molecules increases if    

    a) volume is increased

    b) temperature is increased 

    c) catalyst is added    

    d) concentration of B is decreased 

6. The equilibrium, H₂O_(l) → H⁺_(aq)  +  OH^-_(aq) is 

    a) dynamic                    b) static

    c) physical                     d) mechanical

7. The pH of 10^-8 M HCl is

    a) 8                                 b) 7

    c) less than 7                d) greater than 7

8. The relation between pH and pOH is

    a) pH/pOH= 14             b) 14-Ph= pOH

    c) pH X pOH= 14           d) 14/pOH= pH

9. pH of a solution is 4. Its [H⁺] is

    a) 10^-2M                         b) 1/10⁴M

    c) 10^-6M                         d) 10⁴M

10. The [OH^-] of a solution is 1.0 X 10^-10M. The solution is

    a) acidic                          b) basic

    c) neutral                       d) none of the above

11. NaCl is Salt of ….

    a) strong acid and strong base

    b) strong acid and weak base

    c) weak acid and strong base

    d) weak acid and weak base

12. Na₂CO₃ is a salt of

    a) strong acid and strong base

    b) strong acid and strong base

    c) weak acid and strong base

    d) weak acid and strong base

13. If Na₂CO₃ is added to the solution of H₂CO₃, the pH of H₂CO₃ solution

    a) decreases                  b) increases 

    c) remains constant     d) cannot predicted

14. In CH₃COOH/CH₃COONa buffer, the reserve acidity is 

    a) CH₃COO^-                     b) Na⁺

    c) H⁺                               d) CH₃COOH

15. The solubility of PbI2 is related to its solubility product by the equation

    a) K_sp= S²                        b) K_sp= 4S³

    c) K_sp= 37S⁴                   d) K_sp= 4S²

16. The solubility product of CaF₂ is,

    a) [Ca²⁺][2F^-]                 b) [Ca²⁺][2F^-]²

    c) [Ca²⁺][F^-]²                  d) [Ca²⁺][F^-]

17. The pH of 3 X 10^-4 M KOH is,

    a) 3.52                            b) 10.48

    c) 11.6                            d) 7.5

18. The buffer solution is

    a) NaCl/HCl                   b) HCOOH/HCOOK

    c) K₂SO₄/H₂SO₄          d) NH₄OH/KOH

19. Fir which of the following reactions, an equilibrium constant will be called solubility product.

    a) H₂O_(l)  →H⁺_(aq)  +  OH^-_(aq)                                   

    b) PbF_2(s)  → Pb²⁺_(s)  +  2F^-_(aq)

    c) CH₃COOH_(aq) → CH₃COO^-_(aq) +  H⁺_(aq)                                   

    d) NH₄⁺_(aq)→ NH_3(aq)  +  H⁺_(aq)

20. The solution of a salt is basic. The salt must be

    a) KNO₃                          b) NaCN

    c) CH₃COONH₄                       d) NH₄NO₃

_{7. Surface Chemistry:}

1. Adsorption is

    a) exothermic               b) endothermic

    c) irreversible               d) bulk phenomenon

2. As the temperature of the solid surface increases, the extent of adsorption of a gas    

    a) increases                   

    b) decreases

    c) remains unchanged 

    d) first increases then decreases

3. The critical temperature of Cl₂, NH₃, SO₂ and N₂ are respectively 417K, 406K, 430K and 126K. The gas adsorbed in highest amount will be

    a) N₂                          b) NH₃                   c) SO₂                   d) Cl₂

4. If the pressure of a gas is increased, its extent of adsorption will  

    a) decrease                   

    b) increase at all pressures

    c) increase at all low pressure only

    d) decrease at high pressures  

5. Given the sequence of reactions,

  NH₂NO_{2 (aq)} + OH^-_(aq)     →       NH₄NO₂^-_(aq) + H₂O _(l)

  NH₄NO₂^-_(aq)          →      N₂O_(g) + OH^-_(aq)

  The catalyst for the overall reaction is,

    a) OH^-_(aq)                        b) NH₂NO_2(aq)

    c) NH₄NO₂^-_(aq)                d) N₂O_(g)

6. In the reaction,

  H₂O_2(aq) ----- ^I- →H₂O + ½ O₂

  I^- is,

    a) heterogeneous catalyst  b) homogeneous catalyst  

    c) enzyme catalyst               d) acid catalyst

7. The bond formed by a gaseous reactant with the surface of solid catalyst is

    a) ionic                           b) coordinate

    c) covalent                    d) metallic

8. The rate of reaction depends on the surface area of  catalyst in

    a) homogeneous catalysis  b) enzyme catalysis

    c) acid catalysis                     d) heterogeneous catalysis

9. Enzymes are

    a) homogeneous catalysis  b) heterogeneous catalysis

    c) acid catalysis                     d) base catalysis

10. For the conversion of O₂ to O₃ in the atmosphere,nitric oxide is 

    a) enzyme catalyst                 b) heterogeneous catalyst

    c) homogeneous catalyst     d) base catalyst  

11. The size of colloidal particles lies between

    a) 10^-10 m to 10^-9 m      b) 10^-6m to 10^-4m  

    c) 10^-9m to 10^-6m         d) 10^-5m to 10^-2

12. A sol is a dispersion of

    a) solid in a liquid         b) liquid in a solid

    c) liquid in a liquid        d) gas in a liquid

13. Milk is

    a) an emulsion              b) a gel

    c) a sol                            d) an aerosol

14. Smoke is a colloidal dispersion of

    a) gas in liquid               b) liquid in gas

    c) liquid in gas               d) solid in gas

15. Fog is a colloidal dispersion of

    a) gas in liquid               b) solid in gas

    c) liquid in gas               d) liquid in solid

16. A handful of sand is stirred into water. The mixture will be

    a) true solution             b) colloidal solution

    c) suspension                d) homogeneous solution

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