PPSC Chemistry Full Book Test With Answers

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PPSC Chemistry Full Book Test

Sr. # Questions Answers Choice
1 The large increase in the rate of a reaction on rise in temperature is due to. The lowering of activation energy The decreases in mean free path The increase in collision frequency The increase in the number of molecules having more than the threshold energy
2 A catalyst increases the rate of a reaction because. It provides the necessary energy to the colliding molecules to cross energy barrier It decreases the heat of the reaction It decreases the order of the reaction It provides a different path of lower activation energy.
3 The half life period of any first order reaction. Is half the specific rate constant Is independent of the initial concentration Is always the same whatever the reaction Is directly proportional to the initial concentration of the reactant
4 They hydrolysis of methly acetate is a reaction of. First order Second order Third oirder Fourth order
5 For a chemical reaction A ___________ produce, the rat of the reaction doubles when the concentration of A is increased by 4 times the order of the reaction is. 0 1 1/2 4
6 The minimum amount of energy that the reacting molecules must posses at the time of collations in under to produce effective collisions is called. Free energy Threshold energy Activation energy External energy
7 Point out the incorrect statement. Rate law is an experimental fact whereas law of mass action is a theoretical in nature. Rate law is always different from the expression of law of mass action Rate law is more informativeness than law of mass action Order of the reaction is equal to the sum of the exponents of concentration terms in the case law.
8 Which of the following statement about molecularity is not correct. It cannot be fraction It can be obtained from balanced equation It may be or may not be equal to the order of the reaction it can not be more than 3
9 Which of the following is an acceptable value fo the molecularity. 0 2 6 3/2
10 For an elementary reaction
2A + B ------------------- C + D
The molecularity of the reaction is.
 1 2+ 3 4
11 The second order rate constant can have units. dm-6 mol 2 s-1 dm3 mol s-1 dm<sup>3</sup> mol<sup>-1</sup> s<sup>-1</sup> dm6 mol-1 s-1
12 The rate constant for 3rd order reaction has the dimentions of. mol-2 s-1 I2 mol-2 s-1 mol I -1 s-1 I-1 mol -1 s-1
13 The rate constant of a reaction has same units as the rate of the reaction The reaction is of. Second order First order Three order Zero order
14 The dimensions for first order rate constant are. s-1 s mol-1 mol-1 s-1 s
15 The rate constant of a reaction depends on Concentration of reactants Concentration of products Temperature Time
16 The rate at which a substance reacts depends on its. Molecular mass Active mass Equivalent mass Molar mass
17 Usually the rate of the reactions is expressed as. mol dm-1 mol dm-3 s-1 mol dm-2 s-1 mol 2 dm-3 s-1
18 The change in the concentration of the reactant of product per units time is called. Order of the reaction Melecularity of the reaction Rate of reaction None of the above
19 Which of the following factors does not effect the rate of the reaction. Pressure Temperature Concentration Catalyst All of the above
20 The branch of chemistry which deals with the rate of reaction as well as mechanism is known as Wave mechanism Classical thermodynamcis Chemical kinetics Phtochemistry
21 A compound with an congruent melting point decomposes on heating into. A liquid of the same composition as the solid A new solid phase and a solution with a compositional from that of the solid phase A new solid phase and a solution with the same composition as that of the solid phase A solution of fixed composition
22 The temperature of which the compound melts into a liquid to the same composition as the solid is called the Congruent melting point Incongruent melting point Peritectic temperatures Metastable point
23 The number of degree freedom at the triple point for the water system in. One Two Three Zero
24 The number of degrees of freedom and number of components for a system of containing undissolved salt , in equilibrium with water vapor are. 2,2 3 , 2 1 , 1 1 , 2
25 For a single -component system, the maximum degree of freedom in 1 2 3 Between 3 and 6
26 Sulphur can exist in One phase Two phase Three phase Four phase
27 The maximum degree of freedom for a pure substance under equilibrium constitutions is 1 2 3 zero
28 In a one -component system the maximum number of phase that can consist in equilibrium is. 1 2 3 4
29 In a system , when the chemical potential of each component is the same for all phases. the equilibrium is said to be in Metastable equilibrium Thermal equilibrium Composition equilibrium Mechanical equilibrium
30 The phase rule was deduced by Gibbs Thomson Troution Henry
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