This section includes InterviewSolutions, each offering curated multiple-choice questions to sharpen your knowledge and support exam preparation. Choose a topic below to get started.
| 24801. |
The rate constant of the reaction A to B is 0.6 x 10^-3 Molar per second. If the concentration of A is 5 M then concentration of B after 20 minutes is |
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Answer» 1.08 M `therefore` Conc., of B = 0.72 M |
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| 24802. |
The rate constant of the reaction A to B is 0.6xx10^(-3) mole per second. If the concentration of A is 5 M, then concentration of B after 20 minutes is : |
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Answer» `0.36` M |
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| 24803. |
The rate constant of the reaction : 2H_(2)O(aq)to2H_(2)O(l)+O_(2)(g) is 3xx10^(-3)min^(-1). At what concentration of H_(2)O_(2), the rate of the reaction will be 2xx10^(-4)M s^(-1) ? |
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Answer» `6.67xx10^(-3)M` `2xx10^(-4)=(3XX10^(-3))/(60)xx[H_(2)O_(2)]` `[H_(2)O_(2)]=4M]` |
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| 24804. |
The rateconstantof reactionis 5xx10^(-2) "litre " ^(3)"mole"^(-3) "min"^(-1) theorderofreactionis |
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Answer» `1` when`n= 4, K= "litre"^(3)"mole" ^(-3) MIN^(-1)` |
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| 24805. |
The rate constant of reaction, 2A + B rarr C is 2.57xx10^(-5)"L mole"^(-1)sec^(-1) after 10 sec,, 2.65xx10^(-5)"L mol"^(-1)sec^(-1) after 20 sec., and 2.55xx10^(-5)"L mole"^(-1)sec^(-1) after 30 sec. The order of the reaction is : |
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Answer» 0 |
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| 24806. |
The rate constant of raction is 0.2 "min"^(-1). The order of the reaction is |
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Answer» SECOND |
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| 24807. |
The rate constant of reaction is 3xx10^-3atm^-2sec^-1 . The order of reaction is |
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Answer» 1 |
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| 24808. |
The rate constant of n^(th)order reaction has units : |
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Answer» `LITRE^(1-n)MOL^(1-n)sec^-1` |
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| 24809. |
The rate constant of nth order has units: |
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Answer» `"litre"^(1-n)MOL^(-1)sec^(-1)` `k = ("rate")/(["conc."]^n)` Units of `k = (mol L^(-1)s^(-1))/((molL^(-1))^n)= mol^(1-n) L^(n - 1) s^(-1)` |
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| 24810. |
The rate constant of first order reaction whose half-life is 480 s, is |
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Answer» `1.44 xx 10^(-3)s^(-1)` `implies ""k=(0.693)/(t_(1//2))=(0.693)/(480 sec)=1.44 xx 10^(-3)s^(-1)` |
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| 24811. |
The rate constant of a first order reaction is 0.60" sec"^(-1). What is its half-life period? |
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Answer» SOLUTION :`K=0.50sec^-1` HALF LIFE PERIOD, `t_(1/2)=0.693/(0.50sec^-1)=1.39 SEC.` |
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| 24812. |
Derive an expression for the rate constant of first order reaction. The rate constant of first order reaction is 0.346" min"^(-1). What is the half-life? |
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Answer» Solution :`K=0.346 min^-1` HALF life PERIOD`t_(1/2)=0.693/K` or,`t_(1/2)=0.693/(0346min^-1)`=2 MINUTES |
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| 24813. |
The rate constant of a second order reaction, 2A toProducts, is 10^(-4)" lit mol"^(-1)" min"^(-1). The initial concentration of the reactant is 10^(-2)" mol lit"^(-1). What is the half-life (in min) ? |
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Answer» 10 `t_(1//2) = (1)/("Rate CONSTANT" XX "Initial CONC.") = (1)/(ka)` `=(1)/(10^(-4) L mol^(-1) min^(-1) xx 10^(-2) mol L^(-1))` ` = 10^(6) min` |
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| 24814. |
The rate constant of a reaction of a reaction increases by 5% whenthe temperature of the reaction is increased from 300 to 301 K wheres equilibrium constant increases only by 2%. Calculate the activation energy for the forward as well as backward reaction. |
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Answer» Solution :ACCORDING to Arrhenius EQUATION, `log""(k_(2))/(k_(1))=(E_(a,f))/(2.303"R")((T_(2)-T_(1))/(T_(1)T_(2)))` If `k_(1)=k" at "300" K, then at "301" K,"k_(2)=k+(5)/(100)k=1.05k` `:.log""(1.05k)/(k)=(E_(a,f))/(2.303xx8.314" JK"^(-1)MOL^(-1))((301" K"-300" K")/(300" K"xx301" K"))` `:.E_(a,f)=(log1.05)xx2.303xx(8.314" JK"^(-1)mol^(-1))xx300xx301" (K) "=366554" J mol"^(-1)=36.65" kJ mol"^(-1)` According to van't Hoff equation (giving the effect of temperature on equilibrium constant), `log""(K_(2))/(K_(1))=(DeltaH^(@))/(2.303"R")((T_(2)-T_(1))/(T_(1)T_(2)))` If `K=K_(1)" at "300" K, then at "301" K","K"_(2)="K"+(2)/(100)"K"=1.02" K"` `:.log""(1.02"K")/("K")=(DeltaH^(@))/(2.303xx8.314" JK"^(-1)mol^(-1))((301"K"-300"K")/(300"K"XX301"K"))` or `DeltaH^(@)=" Activation energy for forward reaction-Activation energy for backward reaction"=E_(a,f)-E_(a,b)` `:.E_(a,b)=E_(a,f)-DeltaH^(@)=36.65-14.87" kJ mol"^(-1)=21.78" kJ mol"^(-1).`
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| 24815. |
The rate constant of a zero order reaction in A is 0.003 "mol L"^(-1) "sec"^(-1). How long will it take for the initial concentration of A to fall from 0.10M to 0.075 M ? |
| Answer» SOLUTION :`t=([A]_0 -[A])/K=(0.10-0.075)/0.003`=8.3 SEC | |
| 24816. |
The rate constant of a reaction is equal to the rate of reaction when |
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Answer» Concentration of all REACTANTS are unity |
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| 24817. |
The rate constant of a reaction is independent of |
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Answer» temperature |
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| 24818. |
The rate constant of a reaction is equal to rate of reaction |
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Answer» when oncentrations of REACTANTS do not CHANGE with time |
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| 24819. |
The rate constant of a reaction is given byk=2.1xx10^10 exp(-2700//RT). It means that |
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Answer» log k versus `1/T` will be a straight LINE with SLOPE `=(-2700)/(2.303R)` Given, `k=2.1xx10^10xxe^(-2700//RT)` ![]() INTERCEPT =log A - log `(2.1xx10^10)` = 10.32 |
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| 24820. |
The rate constant of a reaction is given by k=2.1xx10^(10)C^(-(2700)/(2.303R) It means that |
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Answer» LOG K vs `(1)/(T)` will be straight line with slope `=(-2700)/(2.303R)` |
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| 24821. |
The rate constant of a reaction is given by k=2.1xx10^(10)" exp "(-2700/RT) It means that |
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Answer» log k vs. `1//T` will be a straight line with slope (d) is wrng because half - life of the reactions decreases with incerease of temperature ( as reaction BECOMES FASTER ). |
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| 24822. |
The rate constant of a reaction is doubled when the temperature increased from400K to 410K. Calculate the activation energy (Ea) [R = 8.314 JK^(-1) " mol"^(-1)] . |
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Answer» SOLUTION :`log""(k_2)/(k_1) = (E_(a))/(2.303R) [(T_2 - T_1)/(T_1T_2)]` ` log 2 = (E_a)/(2.303 xx 8.314 ) [(410-400)/(400 xx 410)]` ` 0.310 = (E_a)/(19.147)[(10)/(164000)]` `E_a = (0.301 xx 19.147 xx 164000)/(10)` `= 94517 "Jmol"^(-1) OR 94.517 "kJmol"^(-1)` |
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| 24823. |
The rate constant of a reaction is 5.8xx10^(-2)s^(-1). The order of the reaction is .......... |
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Answer» First order |
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| 24824. |
The rate constant of a reaction is 5.8xx10^(-2)s^(-1). The order of the reaction is |
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Answer» FIRST ORDER |
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| 24825. |
The rate constant of a reaction is 2xx10^-5 sec^-1. If the initial concentration is 0.1 M, the initial rate is |
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Answer» `2xx10^-4 M sec^-1` |
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| 24826. |
The rate constant of a reaction is 2xx10^(-3)min^(-1) at 300 K temperature .By increase in temperature by 20K,its value becomes three time,then calculate the energy of activation of the reactuon .what will be its rate constant at 310 K temperature? |
| Answer» Solution :`E_(a)`=10480 cal,K(310 K)=`3.126xx10^(-3)MIN^(-1)` | |
| 24827. |
The rate constant of a reaction is 2xx10^(-3) min^(-1) at 300 K temperature .By increase in temperature by 10 K its value becomes doubl. Calculate energy of activation .Calculation the rate constant at 320 K. |
| Answer» SOLUTION :`E_(a)`=12810 cal,k(320 K)=`7.659xx10^(-3)min^(-1)` | |
| 24828. |
The rate constant of a reaction is 2.5xx10^(-2)" L mol"^(-1)s^(-1). Calculate the initial rate with concentration 0.2" mol L"^(-1). |
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Answer» Solution :From the units of rate constant, order of the reaction is 2. For a SECOND order reaction, rate = k `"[concentration]"^(2)` Initial rate of the reaction `=2.5xx10^(-2)(0.2)^(2)=1xx10^(-3)" MOL L"^(-1)s^(-1)` |
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| 24829. |
The rate constant of a reaction is 2.5xx10^-2mole^-1 lit sec^-1. The order of the reaction is |
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Answer» zero |
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| 24830. |
The rate constant of a reaction is 2.1xx 10^(-2)mol^(-2)litre^3 min^(-1). The order of reaction is |
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Answer» zero ORDER |
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| 24831. |
The rate constant of a reaction is 1.5xx10s^-1 at 100^@C. Calculate the value of activation energy for the reaction. |
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Answer» SOLUTION :From RELATION. `"LOG" K_2/K_1=E_a/(2.303R)[1/T_1-1/T_2]"implieslog"(4.5xx10^7)/(1.5xx10^7)` `=E_a/(2.303xx8.314)[1/323-1/373]IMPLIES"LOG3"=[E_a//(19.147)]xx50//(323xx373]` `E_a=(0.4771xx19.147xx323xx373)/50impliesE_a=22.01kj mol^-1` |
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| 24832. |
The rate constant of a reaction is 1.5xx10^7s^-1 at 50^@Cand 4.5×10^7s^−1 at 100^@C. Calculate the Arrhenius parameter for the reaction. |
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Answer» SOLUTION :From RELATION. `"LOG" K_2/K_1=E_a/(2.303R)[1/T_1-1/T_2]"implieslog"(4.5xx10^7)/(1.5xx10^7)` `=E_a/(2.303xx8.314)[1/323-1/373]IMPLIES"LOG3"=[E_a//(19.147)]xx50//(323xx373]` `E_a=(0.4771xx19.147xx323xx373)/50impliesE_a=22.01kj mol^-1` |
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| 24833. |
The rate constant of a reaction is 1.5 xx 10^(7)s^(-1) at 50^(@)C and 4.5 xx 10^(7) s^(-1) at 100^(@)C. Evaluate the Arrhenius parameters A and E_(a). |
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Answer» SOLUTION :Apply Arrhenius.s EQUATION. `2.19 XX 10^4 J//"mol" , 5.4 xx 10^20 s^(-1)` |
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| 24834. |
The rate constant of a reaction is 1.2xx10^(-5) "mol"^(-2) "litre"^(2) s^(-1) the order of the reaction is : |
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Answer» zero |
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| 24835. |
The rate constant of a reaction is 0.69 xx 10^(-1) "min"^(-1) and the initial concentration is0.2 mol l^(-1) . The half - life period is |
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Answer» 400 sec `t_(1//2) = (0.693)/(0.69 xx 10^(-1)) = (0.693 xx 60)/(0.69 xx 10^(-1)) = 600` sec. |
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| 24836. |
The rate constant of a reaction is 10.8 xx 10^(-5) mol dm^(-3)s^(-1). The order of the reaction is |
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Answer» ZERO |
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| 24837. |
The rate constant of a reaction has s^-1 units. The reaction is of ….. |
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Answer» THIRD order |
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| 24838. |
The rate constant of a reaction has same units as the rate of reaction. The reaction is of ….. |
| Answer» Answer :D | |
| 24839. |
The rate constant of a reaction depends upon |
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Answer» temperature |
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| 24840. |
The rate constant of a reaction depend on. |
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Answer» Temperature |
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| 24841. |
The rate constants of a reaction at 700 K and 760 K are 0.011" M"^(-1)s^(-1) and 0.105" M"^(-1)s^(-1) respectively. Calculate the values of Arrhenius parameters. |
| Answer» SOLUTION :`2.824xx10^10` | |
| 24842. |
The rate constant of a reaction changes when |
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Answer» a catalyst is ADDED |
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| 24843. |
The rate constant of a reaction changes with |
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Answer» Pressure |
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| 24844. |
The rate constant of a reaction at temperature 200K is 10 times than the rate constant at 400K . What is the activation energy (E_(a)) of the reaction (R=gas constant) ? |
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Answer» 1842.4 R |
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| 24845. |
The rate constant of a reaction at temperature 200 K is 10 times less than the rate constant at 400K . What is the activation energy (E_(a)) of the reaction (R = gas constant ) |
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Answer» 1842.4 R |
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| 24846. |
The rate constant of a reaction at 500 K and 700 K are 0.02 s^(-1) and 0.07 s^(-1) respectively .Calculate the values of E_(a) and A. |
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Answer» SOLUTION :Calculation of `E_(a)`: `log(K_(2))/(k_(1))=(E_(a))/(2.303 R)((T_(2)-T_(1))/(T_(1)T_(2)))` `log (0.07 s^(-1))/(0.02 s^(-1))=(E_(a))/(2.303xx8.314 JK^(-1)mol^(-1))xx((700-500)/(700xx500))` `therefore log 3.5=(E_(a)xx200)/(2.303xx8.314xx700xx500)J mol^(-1)` `therefore E_(a)(0.5441xx2.303xx8.314xx700xx500)/(200) J mol^(-1)` `K=Ae^(-(E_(a))/(RT))` Where,`E_(a)=18231 J mol^(-1)` 500 K temp.`K_(1)=0.02 s^(-1)` |
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| 24847. |
The rate constant of a reaction at 400 and 200 K are 0.04 and 0.02s^(-1) respectively. Calculate the value of activation energy . |
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Answer» Solution :According the ARRHENIUS equation `log(k_2/k_2)=E_a/(2.303R)((T_2-T_1)/(T_1T_2))` `T_2 =400K , k_2=0.04s^(-1)` `T_1=200K , k_1=0.02s^(-1)` `log(0.04s^(-1)/(0.02s^(-1)))=(E_a)/(2.303xx8.314"J K "^(-1) MOL^(-1))((400K-200K)/(200Kxx400K))` `log(2)=E_a/(2.303xx8.314" J K "^(-1)mol^(-1))((1)/(400K))` `E_a=log(2)xx2.303xx8.314"JK "^(-1)"mol"^(-1)xx400K` `E_a=2305"J mol"^(-1)` |
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| 24848. |
The rate constants of a reaction at 500 K and 700 K are 0.02s^(-1) and 0.07s^(-1) respectively. Calculate the values of E_(a) and A. |
| Answer» SOLUTION :`18.23 "KJ MOL"^(-1)`, 1.603 | |
| 24849. |
The rate constant of a reaction at 200K is 10 times less than rate constant at 400K. Value of E_a? [R = gas constant] |
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Answer» `1842.4` R |
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| 24850. |
The rate constant of a raction at 500 K and 700 K are 0.02 s^(-1) and 0.07s^(-1) respectively. Calculate the value of E_(a) |
| Answer» SOLUTION :18.230 KJ | |