This section includes 7 InterviewSolutions, each offering curated multiple-choice questions to sharpen your Current Affairs knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
At Boyle temperature , what is the value of compressibility factor of a real gas ? |
| Answer» Solution :At BOYLE temperature , the VALUE of compressibility FACTOR of a real GAS is 1 . | |
| 4. |
At ATP, the least volume will be occupied by 15 g of which one of the following ? |
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Answer» Solution :At NTP the LEAST volume will be occupied by 15 g of `O_(2)`. volume of `O_(2)=(15)/(32)xx22.4=10.5` |
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| 5. |
At at certain temperature, the value of the slope of the plot of osmotic pressure (pi) against concentration (C in mol L^(-1)) of a certain polymer solution is 291 R. The temperature at which osmotic pressure is measured is (R is gas constant) |
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Answer» `271^(@)C` `there RT = 291 R RARR T = 291 K` `thereforeR T = (291 - 273)^(2)C = 18^(@)C` |
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| 6. |
At anode in the electrolysis of fuscd sodium chloride |
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Answer» `NA^(+)` is oxidised |
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| 7. |
At anode in the electrolysis of fused NaCl: |
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Answer» `NA^(+)` is oxidised |
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| 8. |
At absolute zero, the entropy of a perfect cyrstal is zero. This is which law of thermodynamics ? |
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Answer» FIRST LAW of thermodynamics |
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| 9. |
At absolute zero temperature, the total kinetic energy of the molecules is : |
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Answer» MAXIMUM |
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| 10. |
At an under water depth of 400 feet, the pressure is 10 atm. What should be the mole fraction of oxygen in dibing gas for partial pressure of oxygen in the mixture to be 0.2 atm, the same as in air at 1 atm |
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Answer» <P>`0.2` `X_(O_(2)) = (0.2)/(10) = 0.02` |
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| 11. |
At a temperature of 20^(@)C, vapour pressure of water is 17.5 Torm. If relative humidity is 45% Calculate the moves of water present in one litre of air at 20^(@)C. |
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Answer» SOLUTION :`RH=0.45=(P_(H_(2)O))/(17.5) rArr P_(H_(2)O)=0.45xx17.5=7.88` TORR `=0.0104` atm `PV =NRT rArr n=(PV)/(RT)=(0.0104xx1)/(0.0821xx293)=4.3xx10^(-4)` mol |
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| 12. |
At a very low pressure and critical temperature, the molar volume of N_(2) gas is 0.208 L. The compression-factor of N_(2) gas at the above condition will not be (assume N_(2) to be van der Waals' gas, b = 0.037 L" mol"^(-1) = van der Waals' constant) |
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Answer» `0.4` |
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| 13. |
At a temperature of 20^(@)C , vapour pressure of water is 17.5 torr. If relative humidity is 45% , calculate the moles of water present in one litre of air at 20^(@)C. |
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Answer» Solution :Relative humidity `= (" Partial pressure of " H_(2) O " in air ")/("Vapour pressure of " H_(2) O)` ` :.`Partial pressure of `H_(2) O ` in air , `p_(H_(2)O) = 0.45 xx 17.5 ` = 7.88 TORR = 0.0104 ATM PV = nRT ` n = ( PV)/( R T ) = ( 0.0 104 xx 1 )/( 0.0 821 xx 293 ) = 4.3 xx 10^(-4) mol` |
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| 14. |
At a temperature of 0 K, the total energy of a gaseous diatomic molecule AB is approximately given by: E=E_(o)+E_(vib) where E_(o) is the electronic energy of the ground state, and E_(vib) is the vibrational energy. Allowed values of the vibrational energies are given by the expression: E_(vid)=(v-1/2)epsilon "" v=0, 1, 2, ....... "" epsilon=h/(2pi)sqrt(k/mu) "" mu(AB)=(m_(A)m_(B))/(m_(A)+m_(B)) where h is the planck's constant, is the vibration quantum number, k is the force constant, and is the reduced mass of the molecule. At 0K, it may be safely assumed that is zero, and E_(o) and k are independent of isotopic substitution in the molecule. Deuterium, D, is an isotope of hydrogen atom with mass number 2. For the H_(2) molecule, k is 575.11 N m^(-1), and the isotopic molar masses of H and D are 1.0078 and 2.0141 g mol^(-1), respectively. At a temperature of 0K : epsilon_(H_(2))=1.1546 epsilon_(HD) and epsilon_(D_(2))=0.8167 epsilon_(HD) ul("Calculate") the electron affinity, EA, of H_(2)^(+) ion in eV if its dissociation energy is 2.650 eV. If you have been unable to calculate the value for the dissociation energy of H_(2) then use 4.500 eV for the calculate. |
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Answer» {:(H_(2)^(+)+e rarrH_(2),,,EA(H_(2)^(+))=-IP(H_(2))),(H_(2)^(+)rarrH^(+)+H,,,DE(H_(2)^(+))=2.650 eV),(H rarr H+ + e,,,IP(H)=13.598 eV),(H_(2) rarr H +H,,,DE(H_(2))=4.478 eV):}` `EA(H_(2)^(+))=DE(H_(2)^(+))-IP(H)-DE(H_(2))=2.650-13.598-4.478=-15.426 eV` ELECTRON AFFINITY `H_(2)^(+)=-15.426 eV` `=-15.426 eV` |
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| 15. |
At a temperature of 0 K, the total energy of a gaseous diatomic molecule AB is approximately given by: E=E_(o)+E_(vib) where E_(o) is the electronic energy of the ground state, and E_(vib) is the vibrational energy. Allowed values of the vibrational energies are given by the expression: E_(vid)=(v-1/2)epsilon "" v=0, 1, 2, ....... "" epsilon=h/(2pi)sqrt(k/mu) "" mu(AB)=(m_(A)m_(B))/(m_(A)+m_(B)) where h is the planck's constant, is the vibration quantum number, k is the force constant, and is the reduced mass of the molecule. At 0K, it may be safely assumed that is zero, and E_(o) and k are independent of isotopic substitution in the molecule. Deuterium, D, is an isotope of hydrogen atom with mass number 2. For the H_(2) molecule, k is 575.11 N m^(-1), and the isotopic molar masses of H and D are 1.0078 and 2.0141 g mol^(-1), respectively. At a temperature of 0K : epsilon_(H_(2))=1.1546 epsilon_(HD) and epsilon_(D_(2))=0.8167 epsilon_(HD) A molecule H_(2) in the ground state dissociates into its atoms after absorbing a photon of wavelength 77.0 nm. ul("Determine") all possibilities for the electronic states of hydrogen atoms produced. For each case calculate the total kinetic energy, KE, in eV of the disociated hydrogen atoms. |
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Answer» The energy of `H2` molecule in its ground STATE is `-31.675 eV`. `lambda=77.0 nm` `E_("photon")=(hc)/lambda=(6.6261.10^(-34)xx3.00*10^(-8))/(77.0*10^(-19))=2.58 10^(-18) J` `E_("photon")=(6.6261*10^(-34))/(1.602*10^(-19))=16.1 eV` `DeltaE=E_(n_(1))+E_(n_(2))-E_(n_(H_(2)))=-R_(H)/n_(1)^(2)-R_(H)/n_(2)^(2)-(31.675) lt 16.1 eV` `n_(1)=1"" n_(2)=1` `DeltaE=-13.5984/1^(2)-13.5984/1^(2)+31.675=4.478 eV` `KE=16.1-4.478=11.6 eV` `n_(1)=1, n_(2)=2` or `n_(1)=2, n_(2)=1` `DeltaE=-ul(13.5984)-ul(13.5984)+31.675=14.677 eV` `KE=16.1-14.677=1.4 eV` `n_(1)=2, n_(2)=2` `DeltaE=-13.5984/2^(2)-13.5984/2^(2)+31.675=24.880 eV gt 16.1 eV` `K.E.=16.1-14.677=1.4 eV` Thus, the possibilities are: `{:(H_(2)+,hv rarr,H,+,H),(,n=,1,,1),(,,1,,2),(,,2,,1):}` |
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| 16. |
At a temperature of 0 K, the total energy of a gaseous diatomic molecule AB is approximately given by: E=E_(o)+E_(vib) where E_(o) is the electronic energy of the ground state, and E_(vib) is the vibrational energy. Allowed values of the vibrational energies are given by the expression: E_(vid)=(v-1/2)epsilon "" v=0, 1, 2, ....... "" epsilon=h/(2pi)sqrt(k/mu) "" mu(AB)=(m_(A)m_(B))/(m_(A)+m_(B)) where h is the planck's constant, is the vibration quantum number, k is the force constant, and is the reduced mass of the molecule. At 0K, it may be safely assumed that is zero, and E_(o) and k are independent of isotopic substitution in the molecule. Deuterium, D, is an isotope of hydrogen atom with mass number 2. For the H_(2) molecule, k is 575.11 N m^(-1), and the isotopic molar masses of H and D are 1.0078 and 2.0141 g mol^(-1), respectively. At a temperature of 0K : epsilon_(H_(2))=1.1546 epsilon_(HD) and epsilon_(D_(2))=0.8167 epsilon_(HD) ul("Calculate") the dissociation energy, DeltaE, in eV of a hydrogen molecule in its ground state such that both H atoms are produced in their ground states. |
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Answer» For `n=1 : "" DeltaE=2(-13.5984)-(-31.675)=4.478 EV` |
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| 17. |
At a temperature and under high pressure, K_w(H_2O)=10^(-10).A solution of pH 5.4 under those conditions is said to be : |
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Answer» ACIDIC |
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| 18. |
At a suitable pressure near the freezing point of ice, there exists: |
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Answer» Only ice |
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| 19. |
At a suitable pressure near the freezing point of ice, there exists |
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Answer» only ice |
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| 20. |
At a specific pH value the net charge of an amino acid in neutral is called ………………….. |
| Answer» SOLUTION :ISO ELECTRIC POINT | |
| 21. |
Ata site, low grade copper ores are avilable and Zinc and iron scraps are also avilable . Which of the two scraps would be more suitable for reducing the leached copper ore and why? |
| Answer» Solution :Zinc is present above the iron in electrochemical series. Thus zinc is STRONGER REDUCING agent than iron. So the reduction of copper salt with zinc will be faster than with iron. But zinc is costlier metal than iron, so USING the scrap iron is ADVISABLE and advantageous. | |
| 22. |
At a site, low grade copper ores are available and zinc and iron scraps are also available. Which of the two scraps would be more suitable for reducing the leached copper ore and why? |
| Answer» Solution :Zinc being above IRON in the electrochemical series (more REACTIVE metal is zinc), the reduction will be FASTER in case zinc SCRAPS are used. But zinc is costlier metal than iron so using iron scraps will be advisable and advantageous. | |
| 23. |
Ata site, low grade copper oresare available. Zincand iron scrapsare also available . Which of thetwo scrapeswould be more suitable forreducing the leached copper are ? |
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Answer» SOLUTION :Zincis presentabove the iron in electrochemicalseries. THUS zinc is stronger reducing agentthan iron. So the reductionof copper SALT with zincwill be fasterthanwith iron. Butzincis costliermetal thaniron, so USING the scrap iron is advisableand advantageous. |
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| 24. |
At a site, low grade copper ores are available and zinc and iron scraps are also available. Which of the two scraps will be more suitable for reducing the leached copper ore and why ? |
| Answer» Solution : The`E^(@)`valuefor theredoxcouple` ZN^(2+)//Zn(-0*76 V) `is morenegativethat thastof` Fe ^( 2 +)//Fe ` (`-0*44V`) redox couple.Therefore,zinc is morereactivethan ironand hencereductionwill befasterin caseifzinc scrapsare used. Butzinc is acostliermetaliron sousingiron SCARPS would bemoreeconomical. | |
| 25. |
At a pressure of 760 torr and temperature of 273.15 K, the indicated volume of which system is not consistent with the observation |
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Answer» 14 g of `N_(2) + 16 g` of `O_(2)` ,Volume=22.4L (a) `n=14/28+16/32=1`, volume=`1xx22.4L=22.4L` (b) `n=4/4+44/44=2` volume=`2xx22.4L=44.8L` (c) `n=7/28+36/48=1`, volume= `1 xx 22.4 L =22.4 L` (d) `NH_(3)(g)+HCl(g)toNH_(4)Cl(s),` volume`LTLT`44.8L |
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| 26. |
At a pressure of 1.0 bar, an equilibrium exists at 2000 K between 0.25 mole of Br_2(g) , 0.75 mole of F_2 (g) and 0.497 mole of BrF_3(g) . What will be the amounts of each gas after the pressure on the system has been increased to 2.0 bar and the equilibrium at 2000 K re-established?Br_2(g) + 3F_2 to 2BrF_3(g) |
| Answer» SOLUTION :0.189 MOLE, 0.567 mole, 0.619 mole | |
| 27. |
At a pH of 7 amino acids are |
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Answer» neutral |
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| 28. |
At a particular temperature, the ratio of molar conductance to specific conductance of 0.01 M NaCl solution is |
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Answer» `10^5 cm^3 MOL^(-1)` `(^^_m(OHM^(-1)cm^2mol^(-1)))/(K(ohm^(-1)cm^(-1)))=1000/M=1000/(0.01)cm^3mol^(-1)` `=10^5cm^3mol^(-1)` |
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| 29. |
At a particular temperature the ratio of equivalent conductance to specific conductance of a 0.01 (N) NaCl solution is |
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Answer» `10^( 5)cm^(3)` `(lambda_(eq))/(K) = (ohm^(-1) cm^(2) ge q^(-1))/(ohm^(-1) cm^(-1))= cm^(3) g eq^(-1)` `(lambda_eq)/(K) = (1000)/(N) = (1000)/(10^(-2)) = 10^(5) cm^(3) g eq^(-1)` |
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| 30. |
At a particular temperature, the K_(w) of a neutral solution was equal to 4xx10^(-14) . Calculate the concentration of [H_3O^+] and [OH^-]. |
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Answer» Solution :Given solution is NEUTRAL `therefore [H_3 O^+]=[OH^-]` Let `[H_3 O^+]=x ,` then `[OH^+]=x` `K_(sp)=[H_3O^+][OH^-]` `4XX10^-14=x.x` `x^2=4xx10^(-14)` `x=sqrt(4xx10^(-14))=2XX10^(-7)` |
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| 31. |
At a particular temperature, the K_w of a neutral solution was equal to 4 times 10^-14. Calculate the concentration of [H_3O^+] and [OH^-]. |
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Answer» SOLUTION :GIVEN solution is neutral `THEREFORE [H_3O^+]=[OH^-]` LET `[H_3O^+]=x,` then `[OH^-]=x` `K_w=[H_3O^+][OH^-]` `4 times 10^-14=x.x` `x^2=4 times 10^-14` `x=sqrt(4 times 10^-14)=2 times 10^-7` |
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| 32. |
At a particular temperature, PCl_(5)(g)undergoes 50% dissociation. The equilibrium constant for PCl_(5)(g) rarr PCl_(3)(g) + Cl_(2)(g) is 2atm. The pressure of the equilibrium mixture is |
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Answer» Solution :`PCl_(5) RARR PCl_(3)+ Cl_(2)` `K_(p) = (0.5/1.5)p(0.5/1.5)p/(0.5/1.5)p implies k_(p) = (0.5/1.5)p` `2 = p/3 implies p = 2 xx 3 = 6 atm` |
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| 33. |
At a particular temperature and at a pressure of 1 atm, mass and volume of O_(3) that can be dissolved in 1 L of H_(2)O is m gram and V ml repectively (Assuming ideal gas behaviour of O_(3) and assuming O_(3) does not associate of dissociatein solution). Mass and volulme of O_(3)dissolved in 2L of H_(2)O at same temperature and at a pressure of 5 atm will be: |
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Answer» 5 M GRAM, 5V mL |
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| 34. |
At a given temperaturee, the equilibrium constant for reaction PCl_(5(g))hArrPCl_(3(g))+Cl_(2(g))is 2.4xx10^(-3). At the same temperaturee, the equlibrium constant for reaction PCl_(3(g))+Cl_(2(g))hArrPCl_(5(g))is |
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Answer» `2.4xx10^(-3)` `K=(1)/((2.4xx10^(3)))=4.2xx10^(2)` |
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| 35. |
At a given temperature, when a reversible reaction is carried out in absence of catalyst, the ratio of the rate constants for the forward and reverse reactions is found to be 8.0. At the same temperature, if the reaction is carried out in presence of catalyst, then the ratio will be |
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Answer» gt8.0 |
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| 36. |
At a given temperature, the vapour pressure in mm of Hg of a solution of two volatile liquids A and B is given by the equation p=120-80X_(B)(X_(B)="mole fraction of B") Calculate the vapour pressures of pure A and B at the same temperature. |
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Answer» Solution :When `X_(B)=0`, we have pure A`""therefore""p_(A)^(@)=120-80xx0=120mm` The given EXPRESSION can be written as `""p=120-80(1-X_(A))` When `X_(A)=0`, we have pure B`""therefore""p_(B)^(@)=120-80(1-0)=40mm` Alternatively, for pure B, `x_(B)=1`. HENCE, `p_(B)^(@)=120-80xx1=40mm` |
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| 37. |
At a given temperature, the solubility of a gas in a liquid is directly proportional to the ______of the gas. |
| Answer» SOLUTION :PARTIAL PRESSURE | |
| 38. |
At a given temperature, the reaction, SO_2Cl_2(g) |
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Answer» The concentration of `SO_2`(g) will increase |
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| 39. |
At a given temperature, the reaction A(g)+2B(g)toC(g) , is at equilibrium. At the start of the reaction, p_A = 0.25 atm and p_B = 0.5 atm. When the reaction reaches equilibrium, 50 % of C(g) is found to have formed. Calculate the K_P for the reaction. What initial pressure should B(g) have for the production of 75% C(g)? |
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Answer» SOLUTION :`A(g)+2B(g) at EQUILIBRIUM: =0.125atm=0.25atm=0.25atm `K_p=(p_C)/(P_Axxp_B^2)=(0.125)/(0.125xx(0.25)^2)=16` Let, for 75% YIELD of C(g), the initial pressure of B(g)=p atm `A(g)+2B(g) `=0.0625atm""=p-0.375""=0.1875` `K_p=(p_c)/(p_Axxp_B^2)=16` or `(0.1875)/(0.0625xx(p-0.375)^2)=16" ":.p=0.808atm` |
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| 40. |
At a given temperature the K_c for the reactionPCL_5(g) hArrPCl_3 + Cl_2 is 2.4 xx 10^ -3 At the same temperature the K_c for the reaction PCl_3 + Cl_2 hArr PCL_5(g) is : |
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Answer» `2.4XX10^(-3)` |
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| 41. |
At a given temperature, the first and the second ionisation constants of the acid, H_2A are 1.0xx10^(-5) and 5.0xx10^(-10) respectively. Which of the following comments are true regarding this acid- |
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Answer» The CONCENTRATION of `A^(2-)` ions in 0.01(M) aqueous solution of `H_2A` is 0.01(M) |
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| 42. |
At a given temperature, the equilibrium constant for the reaction :PCl_(5)(g)hArr PCl_(3)(g)+Cl_(2)(g) is 2.4xx10^(-3). At the same temperature, the equilibrium constant for the reaction :PCl_(3)(g)+Cl_(2)(g) harr PCl_(5)(g)is : |
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Answer» `2.4xx10^(-3)` `=4.2xx10^(2)` |
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| 43. |
At a given temperature, the energy of activation of two reaction is same if |
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Answer» The specific RATE constant for the TWO REACTIONS is the same |
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| 44. |
At a given temperature, pH of 0.01(M) aqueous solution o. nitrous acid is 2.67. The concentration of OH^- ions in 0.1(M) aqueous solution of nitrous acid is- |
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Answer» `2.57xx10^(-10)(M)` |
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| 45. |
At a given temperature, oxygen molecules will have the speed that is, in comparison to speed of hydrogen molecules |
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Answer» the same `:.( r ( O_(2)))/( r( H_(2))) = ( 1)/( 4) ` |
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| 46. |
At a given temperature, oxygen gas is more soluble in water than Nitrogen gas. Which one of them has higher value of K_(H)^. |
| Answer» SOLUTION :NITROGEN. | |
| 47. |
At a given temperature, osmotic pressure of a concentrated solution of a substance __ |
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Answer» is higher than that at a dilute solution. |
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| 48. |
At a given temperature, osmotic pressure of a concentrated solution of a substance …….. |
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Answer» is HIGHER than that at a dilute SOLUTION. |
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| 49. |
At a given temperature, NH_3 gas is in a state of equilibrium with N_2 and H_2 gases in a closed container. If the partial pressures of N_2 and H_2 in the mixture are 1.34 and 0.67 atm respectively and the total pressure of the reaction mixture is 4.67 atm, then determine the value of K_p for the reaction : N_2(g)+3H_2(g) |
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Answer» SOLUTION :TOTAL pressure of the mixture = 4.67 ATM. In the mixture, `p_(N_2)=1.34atm,p_(H_2)=0.67atm` `pNH_3=[4.67-(1.34+0.67)]=2.66atm` `N_2+3H_2 |
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| 50. |
At a given temperature, osmotic pressure of a concentrated solution of a substance…… |
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Answer» is HIGHER than that of a DILUTE solution Hence as concetration of sulution increase osmitic pressure will also increase. |
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