Chemistry MCQ Quiz Hub

1. The pH of 10-3 mol dm-3 of an aqueous solution of H2SO4 is
3
2.7
2
1.5

2. Kc value has
No units
Units
Both a & b
None

3. If a buffer solution of higher pH than seven is to be made we use
Strong acid and strong base
Weak acid and strong base
Weak acid and strong base
Weak acid and its salt with strong base

4. Sodium benzoate and benzoic acid are mixed in equimolar ration to form buffer if pKa is 2 what will be the pH?
0
1
2
any one

5. AgCl dissolved with conc (2x10-2) Ksp will be
3.6 x 10-6
3.6 x 10-5
7.2 x 10-6
4 x 10-4

6. In which of the following equilibria will Kc and Kp have the same value?
PCI5 = PCI3 + Cl2
N2 + 3H2 = 2NH
2CO + O2 = CO2
N2 + O2 = 2NO

7. Which of the following will not change the concentration of ammonia at the equilibrium ?
Increase of pressure
Increase of volume
Addition of catalyst
Decrease of temperature

8. pH of an aqueous solution is 5.5. The hydroxyl ion conc. In the solution would be
?5.5
?8.5
10-8.5
10

9. For a reaction involving only gases at 25?C the equilibrium constant can be expressed in terms of molarity Ke or partial pressure Kp. Which is true about the numerical value of Kp?
Kc is generally greaer than Kp
Kc is generally less than Kp
Kc is generally equal to Kp
Kc is equal to Kp if the total moles of reactants and products are equal

10. Which of following is not a base
KOH
NH3
PH3
BF3

11. Which set of solutes will form a buffer when dissolved in water to make 1 litter of solution?
0.0002M HCI
0.2 mole of NaCI with 0.2 mole of HNO3
0.4 mole of CH3COOH with 0.4 mole of NaOH
0.4 mole of NH3 with 0.2 mole of HCI

12. Which one of the following aqueous solutions will be basic?
NaCI
Na2SO4
Na2CO3
FeCl3

13. The value of Kw in an acidic aquueous solution at 298 K is
>10-14
<10-14
101?
10-1?

14. Reaction which proceeds in both directions is called
reversible
irreversible
spontaneous
non-spontaneous

15. Chemical equilibrium state is
dynamic state
static state
free state
unidirectional state

16. Conversion of reactant into product in unit time is called
rate of forward reaction
rate of backward reaction
rate constant
rate co-efficient

17. At start of reaction the concentration of reactants is
high
low
according to Kc
constant

18. Unit of Kc is
moles2dm+6
moles-2dm+6
moles+2dm-6
Kc may or may not have units

19. In case of gases Kc is replaced by
Ka
Kb
Kp
K

20. Rate expression for ammonia synthesis is
Kc=x2/(a-x)(b-x)
Kc=x2/v(a-x)
Kc=4x2/(a-2x)2(b-x)
Kc=4x2v2/(a-x)(b-3x)3

21. When the value of Kc is very small then
reaction is at start
product conc. Is maximum
reactant conc. Is minimum
reaction is completed

22. Catalyst used to speed up the reaction of ammonia synthesis is
V2O5
V2O5 and Pt
Fe
Pieces of Fe crystals are embedded in fused mixture of MgO Al2O3 and SiO2

23. Temperature for preparation of SO3 is
400-500?C
400?C
600?C
200?C

24. By the addition of base in waterpH will be
more than 7
less than 7
equal to 7
no effect

25. Idea of pH and pOH was put forward by
Gibbs
Einstein
Sorenson
Chadwick

26. Negative log of mular concentration of H+ ions is called
pH
pOH
pKa
pKw

27. Ka<10-3 means
Very strong base
Very weak acid
Very strong acid
Very strong salt

28. Any substance which accepts H+ is base favours the concept
Lowrys
Lewis
Arrhenius
None of these

29. Conjugated base of a weak acid is
weak
strong
moderately weak
unstable

30. When sparingly soluble salt is in equilibrium with molar concentration of its oppositely charged ion when the product is called
common ion effect
solubility product
dissociation constant
dissociation constant for an acid

31. Solution having the property of a very little change in pH on adding a small amount of strong acid or base is called
buffer solution
normal solution
standard solution
neutral solution

32. Addition of CH3COOH and CH3COONa gives in water
Standard solution
buffer solution
acidic buffer solution
both b & c

33. Which one of the following is a buffer solution?
brine
blood
glue
solution of CuSO4

34. Solubility of any salt can be determined from
Ka
Kb
Kc
Ksp

35. The pH of human blood is
7
7.35
7.5
7.8

36. By decreasing the pressure the reaction will go to that direction where
volume is decreased
volume increased
heat absorbed
no. of moles of specie decreased

37. Equilibrium state is achieved quickly by the addition of.
reactants
acid
base
catalyst

38. The rate of reaction
Increases as the reaction proceeds
Decreases as the reaction proceeds
Remains the same as the reaction proceeds
May decrease or increase as the reaction proceeds

39. The addition of a catalyst to the reaction system
Increases the rate of forward reaction only
Increases the rate of reverse reaction
Increases the rate of forward but decreases the rate of backward reaction
Increases the rate of forward as well as backward reaction equally

40. The specific rate constant of a first order reaction depends on the
Time
Concentration of the reactant
Temperature
Concentration of the product

41. On increasing the temperature the rate of reaction increases mainly because
The activation energy of the reaction increases
Concentration of the reacting molecules increases
Collision frequency increases
None of these

42. ?d[N2O5]/dt represents
Rate of formation of N2O5
Rate of decomposition of N2O5
order of the reaction
none

43. The value of activation energy is primarily determined by
Temperature
Effective collision
Concentration of reactants
Chemical nature of reactants and products

44. Sum of exponents of molar concentration is called
Order of reaction
Molecularity
Rate of reaction
Average of reaction

45. Spontaneous reactions are
Moderate
Slow
Fast
not natural

46. In rate expression the concentration of reactants is negative. It shows
Concentration of reactant does not change
Concentration of product increases
Concentration of reactant decreases
Concentration of reactant increases

47. Unit of rate of reaction is
Moles dm-3 sec-1
Moles dm-3
Moles sec-1
Mol-1 dm3 sec-1

48. When a graph is plotted between 1/T on X-axis and log k on y-axis a straight line is obtained with a negative slope which has two end in
I and II quadrant
II and III quadrant
III and IV quadrant
II and IV quadrant

49. Rate of disappearance of reactant is equal to
Rate of reaction
Rate of formation of product
Energy released during reaction
a and b

50. Rate of reaction when concentration of reactants are taken as unity is called
Arrhenius constant
Molecularity
Specific rate constant
Ideal rate constant