ECAT Chemistry Online Test With Answers

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ECAT Chemistry Online Test

Sr. # Questions Answers Choice
1 The number of elements in the first, second and third period are 2, 8, 18 8, 2, 18 2, 18, 8 2, 8, 8
2 The horizontal rows in the periodic table are called periods. The number of period are 5 6 7 8
3 The number of groups in the periodic table is 6 7 8 9
4 The period table contains elements in vertical column. these vertical column are called Groups Periods Blocks Sub group
5 In the modern periodic table the elements are placed in the ascending order of their Atomic masses Melting points Boiling points Atomic numbers
6 Doberiner arranged the similar elements into Pairs Triads Triplets Rows
7 The value of activation energy Ea of a reaction can be determined from the value of slope of the straight line obtained by plotting a graph between 1/T and log k. the value of Ea is equal to Slope 1/Slope Slope x R Slope x 2.303 R
8 Which statement about Arrhenius equation is incorrect Factor 'A' called Arrhenius constant depends upon collision frequency of reactants Rate of reaction increase by increasing temperature Rate constant k is increased Activation energy Ea is decreased by rise in temperature
9 The rate constant k of a reaction activation energy Ea and temperature are related by Arrhenius in the form of an equation which is
10 With increases in temperature of 10 K of the reacting gases the rate of reaction is doubled because Increase in number of collisions Number of molecules having energy more than Ea is doubled Increase in order of reaction Increase in surface area
11 The factor which effect the rate of reaction Nature of reactants Surface area Light All of the above
12 Which of the following is not affected by light
13 Which one of the following reaction rate is effected by the light
14 The actual number of atoms or molecules taking part in rate determining step is Rate of reaction Velocity of reaction Order of reaction Molecularly
15 Group l-A elements react with water fastly than the reaction of group ll-A elements because l<sub>A</sub>elements are more soft then ll<sub>A</sub> l<sub>A</sub>elements are non-metals l<sub>A</sub>elements have 1 electron in their outermost s-orbital and are strongly electropositive l<sub>A</sub>elements make ionic bond
16 In an experiment the concentration of a reactant 'A' is doubled the rate increases four times. If concentration in tripled, then rate increases nint times. Thus the rate is proportional to ______ of concentration of 'A' Square root Square Twice Cube
17 Decreases om concentration of reactant is denoted by dc/dt -dc/dt +dc/dt None
18 In thermal decomposition of N2O the half life period for two different initial concentrations of N2O are
(i) 255 second for initial N2O 290 mm Hg
(ii) 212 second for initial N2O 360 mm Hg then it is
 Zero order First order Second order Third order
19 Half life period of a reaction is inversely proportion to the initial concentration of the reactant, then order of reaction is Third order Second order Fist order Zero order
20 Half life period of N2O5is 24 minutes and it remains same where we increase or decrease its initial concentration, then reactions Zero order First order Second order Third order
21 1st order 2nd order Zero order 3rd order
22 Three times Six times Nine times Two times
23 When we perform the same reaction by taking two different initial concentrations of a reactant for a second order reaction then Reaction becomes exothermic Energy of activation is different Mechanism of reaction is changed Half life period is changed
24 Initial concentration of reaction Initial concentration of products Final concentration of products Order of the reaction
25 In exothermic reaction decrease in potential energy of the products will result in Decreases in kinetic energy of the particles Increases in kinetic energy of the particles No change in kinetic energy Decreases in activation energy
26 In the hydrolysis of CH3COOC2H5the acid produced is Inhibitor Catalyst Auto catalyst None of above
27 By the use of catalysis the energy of activation is Decreased Increased Not affected None
28 For effective collisions the molecules slow down before collision and their kinetic energy decreases which results in increase in their Activation energy Average energy Potential energy Collisions frequency
29 For a chemical reaction to take place the particles must have sufficient energy for the effective collisions, the energy is called Average energy Activation energy Potential energy Collision energy
30 Measuring pH Measuring density Titration against standard NaOH Titration against standard KMnO<sub>4</sub>solution
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