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. |
K_(sp) (BaSO_(4)) is1.1 xx 10^(10). In which case is BaSO_(4) precipitated ? |
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Answer» `100 mL of 4xx 10^(-3)M of BaCl _2 +300 mL of 6.0 XX 10^(-4)M of Na_2SO_4` after mixing, ` 4 xx 10 ^(-3)xx 100 =M_2xx 400` ` [ Ba^(+2) ] = 10 ^(-3) M` ` 6 xx 10 ^(-4) xx 300 = M_2 xx 400` ` [SO_4^(-2) ]=4.5 xx 10^(-4)M` ` IP=[Ba^(+2) ][SO_4^(-2) ]= 4.5 xx 10 ^(-7),KsPlt I.P.` |
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| 2. |
Kp value for 2SO_(2(g))O_(2(g)) hArr 2SO_(3(g))is 5.0 atm^(-1). What is the cquilibrium partial pressure of O_(2) ifthe equilibrium pressures of SO_(2) and SO_(3) are equal ? |
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Answer» <P>0.2 `K_(P)=(P_(SO_(3))^(2))/(P_(SO_(2))^(2) xx P_(O_(2)))=(1)/(P_(O_(2)))` (`:. P_(SO_(3))=P_(SO_(2))`) `PO_(2)=(1)/(K_(P))=(1)/(5)=0.2` atm |
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| 3. |
K_p of the following reaction at 700 K is 1.3 xx 10^(-3) atm ^(-1) . The K_Cat same tempertaure for the reaction 2SO_(2)(g)+O_(2)(g) rArr 2SO_(3)(g) will be.......... |
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Answer» `K_(c)= (K_p)/(RT^(Deltans)) = (1.3 xx 10^(-3))/((0.0821 xx 700)^(-1))=7.4 xx 10^(-2)` |
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| 4. |
K_p//K_e for N_2+3H_2 harr 2NH_3 (gaseous phase) at 400 K is |
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Answer» 400 R |
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| 5. |
K_(p)//K_(c) " for the reaction " CO(g) + 1/2 O_(2) (g) hArr CO_(2) (g)is |
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Answer» 1 |
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| 6. |
K_(p) "is" atm^(2) for the reaction: LiCI.3NH_(3)(s)hArrLiCI.NH_(3)(s)+2NH_(3)(g) "at" 40^(@)C. How many moles of ammonia must be added at this temperature to a 5 litre flask containing 0.1 mole of LiCI. NH_(3) in order to completely convert the solid to LiCI.3NH_(3)? |
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Answer» |
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| 7. |
K_(p) is how many times equal to K_(c) for the given reaction ? N_(2(g))+3H_(2(g))hArr2NH_(3(g)) |
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Answer» <P>`(1)/(R^(2)T^(2))` `K_(p)=K(RT)^(-2)` `:.K_(p)=(K_(c))/(R^(2)T^(2))` |
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| 9. |
K_(p) for the reaction, NH_(4)HS(s) Leftrightarrow NH_(3) (g)+H_(2)S(g), at certain temperature is 4"bar"^(2). Calculate the equilibrium perssure. |
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Answer» <P> Solution :Equilibrium constant,`K_(P)=P_(NH_(3)). P_(H_(2)S)=4"bar"^(2)` PARTIAL pressure are given as, `NH_(3)=P_(H_(2)S)=SQRT(K_(p))=2"bar"` `P_(NH_(3))+P_(H_(2)S)=2"bar" +2 "bar"=4 "bar"` |
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| 10. |
K_(p) for the reaction N_(2)O_(4)(g) hArr 2NO_(2) (g) is 0.157 atm at 27^(@)C and 1 atm pressure. Calculate K_(c) for the reaction. |
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Answer» <P> `K_(c) = K_(p)//(RT)^(Delta n) = (0.157 " atm)//(0.0821 L "atm" K^(-1) mol^(-1) xx 300 K)^(1) = 6.37 xx 10^(-3) mol L^(-1)`. |
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| 11. |
K_(p) " for the reaction " N_(2) (g) + 3 H_(2) (g) hArr 2 NH_(3) (g) " at "400^(@)C " is " 1*64 xx10^(-4) atm^(-2)." Find " K_(c). " Alsocalculate " DeltaG^(@) " using " K_(p) and K_(c) " values and interpret the difference ". |
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Answer» Solution :`N_(2) (g) + 3 H_(2) (g) hArr 2 NH_(3) (g)` `Delta n= 2-4 = -2` `K_(p) = K_(c) (RT)^(Delta n)` `1*64 XX 10^(-4) " atm"^(-2) = K_(c) (0*0821) L " atm "K^(-1) mol^(-1) xx 673 K ) ^ (-2) ""(T=400 + 273 K = 673 K)` or `K_(c) = (1*64 xx 10^(-4) "atm"^(-2))/((0*821 xx 673 " atm"^(-1) mol^(-1))^(2))=0*5372 " mol"^(2)L^(-2)` Now,`Delta G^(@) = - 2*303" RT " log K` If `K=K_(p)` ` Delta G^(@) = - 2*303 xx (8*314 " JK"^(-1) mol^(-1)) (673 K) xx log (1*64 xx 10^(-4))` `=-2*303 xx 8*314 xx 673 xx (-3* 7852) " J "mol^(-1) = +48*78 " kj "mol^(-1)` If `K=K_(c)` , `Delta G^(@)= - 2*303 xx (8*314 xx 673 xx (-0*27) " J "mol^(-1) = + 3479 " J "mol^(-1)` INTERPRETING the difference .`DeltaG^(@)` is the FREE energy CHANGE when all the reactants and products are in their standard state. In case of `K_(p)`, standardstate pressure is used which is 1 atm (or now 1 bar) wheras in case of `K_(c)` , standard concentration is used which is 1 mol `L^(-1)` (as already explained on page 7/22). |
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| 12. |
K_(p) for the reaction N_(2) + 3H_(2) hArr 2NH_(3) , is 1.6 xx 10^(-4) atm^(-2) at 400^(@) C. What will be K_(p) at 500^(@)C ? Heat of reaction in this temperature range is-25.14 Kcal. |
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Answer» `1.43 xx 10^(-5) ATM^(-2)` |
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| 13. |
Kp for the reaction 3/2O_(2(g)) overset(rarr)(larr)O_(3(g)) at 25^@C is 2.47 xx 10^(-29). Then DeltaG^@ for the conversion is |
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Answer» `163 kJ mol^(-1)` |
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| 14. |
K_(p) " for the following reaction will be equal to " 3 Fe (s) + 4 H_(2)O (g) hArrFe_(3)O_(4) (s) + 4 H_(2) (g) |
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Answer» <P>`(p_(H_(2)))^(4)(p_(Fe_(3)O_(4)))` |
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| 15. |
K_p for the reaction2SO_3(g) +O_2(g) leftrightarrow 2SO_3(g) is 2.5 times 10^20 atm^-1 at 500K. Calculate the K_p for the reaction SO_3(g) leftrightarrow SO_2(g)+1/2 O_2(g). |
| Answer» SOLUTION :`6.3 TIMES 10^-6 atm^0.5` | |
| 16. |
K_p for the reaction : 2SO_2(g) + O_2(g) hArr 2SO_3(g) is 2.5xx10^10 Calculate the K_p values for the following reactions : (i)SO_2(g) + 1/2O_2(g) hArr SO_3(g) (ii)SO_3(g) hArr SO_2(g) +1/2O_2(g) (iii) 3SO_2(g) + 3/2 O_2(g) hArr 3SO_3(g) |
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Answer» Solution :`2SO_2(G) +O_2(g) hArr 2SO_3(g) "" K_p = 2.5xx10^10` (i)`SO_2(g) +1/2O_2(g) hArr SO_3(g)` `K_i=(K_p)^(1//2)` `=(2.5xx10^10)^(1//2) =1.58xx10^5` (ii)`SO_3(g)hArr SO_2(g) +1/2O_2(g)` `K_(ii)=1/K_i` `=1/(1.58xx10^5)=6.3xx10^(-6)` (III)`3SO_2(g) +3/2O_2(g) hArr 3SO_3(g)` `K_(iii)=(K_p)^(3//2)` `=(2.5xx10^10)^(3//2)=3.95xx10^15` |
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| 17. |
Kp for Lane's process is : |
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Answer» `(P_(H_(2))^(4))/(P_(H_(2)O)^(4))` `4Fe(s)+4H_(2)O(g) harr Fe_(3)O_(4)(s)+4H_(2)(g)` |
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| 18. |
K_(p) for a reaction at 25^(@)C is 10 atm. The activation energy for forward and reverse reactions are 12 and 20 kJ mol^(-1) respectively. The K_(c) for the reaction at 40^(@)C will be: |
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Answer» `4.33xx10^(-1) M` |
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| 19. |
K_p= 0.04 atm at 899 K for the equilibrium shown below. What is the equilibrium concentration of C_2H_6 when it is placed in a flask at 4.0 atm pressure and allowed to come to equilibrium ? C_2H_(6(g)) hArr C_2H_(4(g)) + H_(2(g)) |
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Answer» Solution :`{:("Reaction equilibrium:",C_2H_(6(g)) hArr, C_2H_(4(g)) +, H_(2(g))),("Initial partial pressure :","4.0 ATM","0 atm","0 atm"),("CHANGE in pressure","-p atm","+p atm","+p atm"),("Partial pressure at equilibrium :", "(4-p)atm","p atm","p atm"):}` `K_p=((p_(C_2H_4))(p_(H_2)))/((p_(C_2H_6)))` `therefore 0.04 = ((p)(p))/((4-p))` `therefore p^2+ 0.04 p - 0.16 =0` In this quadratic equation put B= +0.04 , a=1 and c=-0.16 So, `p=(-bpmsqrt(b^2-4ac))/(2a)` `=(-(0.04)pmsqrt((+0.04)^2-4(1)(-0.16)))/2` `=(-(0.04)PM sqrt(0.0016 +0.64))/2` `=(-(0.04) pm sqrt0.6416)/2` `=(-0.04)pm0.8009)/2` OR `(-0.4-0.80009)/2` p = 0.3805 atm = 0.38 atm OR - 0.6005 atm it is possible OR impossible `therefore p_(C_2H_6)`=(4-p)=(4-0.3805)=3.62 atm |
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| 20. |
K_(p) = 0*04 atm at 899 K for the equilibrium shown below. What is the equilibrium concentration of C_(2)H_(6) when it is placed in a flask at 4*0 atm pressure and allowed to came in equilibrium ?C_(2) H_(6) (g) hArr C_(2) H_(4) (g) + H_(2) (g) |
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Answer» <P> Solution :` {:(,C_(2)H_(6)(g),hArr,C_(2)H_(4)(g),+,H_(2)(g)),("Intial pressure",4*0"atm",,0,,0),("At eqm".,4-p,,p,,p):}``K_(p) = (p_(C_(2)H_(4))xx p_(H_(2)))/(p_(C_(2)H_(6))):. 0*04 = p^(2)/(4-p) or p^(2) = 0*16 - 0*04 p ` or ` p^(2) + 0*04 p - 0*16 = 0:.p = (-0*04 PM sqrt(0*0016 - 4(-0*16)))/2 = (0*04 pm 0*89)/2` aking positive value, ` p= (0*80)/2 = 0*40 :.[C_(2)H_(6) ]_(eq)= 4 - 0*40 "atm"= 3* 60 "atm " ` |
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| 21. |
Kolbe's synthesis of 2,2-dimethylpropanoic acid gives the following major product at anode |
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Answer» isoctane |
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| 22. |
Kolbe's electrolysis of sodium salt of 2, 2-dimethyl propanoic acid gives the following majorproduct(s) at anode. |
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Answer» `CO_2` gas
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| 25. |
KO_(2)(potassium superoxide) is used in oxygen cylinders in space and submarines because it |
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Answer» absorbs `CO_(2)` and increases `O_(2)` content Although `KO_(2)` also reacts with moisture of the BREATH but does not completely eliminate it . `4 KO_(2) + 2 H_(2)O to 4 KOH + 3 O_(2)` or `4 KO_(2) + 4 CO_(2) + 2H_(2)O to 4 KHCO_(3) + 3 O_(2)` For further EXPLANATION , |
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| 26. |
Potassium superoxide is used in oxygen cylinders in space and submarines because it |
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Answer» absorbs `CO_(2)` and INCREASE `O_(2)` content |
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| 27. |
KO_(2)(potassium super oxide) is used in oxygen cylinders in space and submarines because it..... |
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Answer» ABSORBS `CO_(2)` and increases `O_(2)` content |
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| 28. |
KO_(2) is used in space crafts and submarines because it |
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Answer» absorbs CO2 and MOISTURE to INCREASE O2 concentration `2KO_(2)+H_(2)O rarr2KOH+3/2O_(2)` |
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| 29. |
Knowing the properties of H_(2)O and D_(2)O , do you think that D_(2)O can be used for drinking purpose ? |
| Answer» Solution :HEAVY water is injurious to human BEINGS, plants and animals SINCE it slows down the rates of reactions occuring in them. Thus, heavy water does not support life so WELL as does ordinary water. | |
| 30. |
Knowing the properties of H_2O and D_2O. Do you think that D_2O can be used for drinking purpose ? |
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Answer» Solution :HEAVY water is injurious to human BEINGS, plants and animals since it SLOWS down the rates of reactions occurring in them. Thus heavy water does not support life so it is not used for drinking Heavy water `(D_2O)` is a oxide of deuterium, the isotope of Hydrogen. Heavy water is extensively used as a moderator in nuclear reactors and in exchange reactions for the study of reaction mechanisms. It can be prepared by EXHAUSTIVE electrolysis of water or as a by PRODUCT in some fertilizer industries. `CaC_2+2D_2O to C_2D_2+Ca(OD)_2` `SO_3 + D_2O to D_2SO_4` `Al_4C_3 + 12D_2O to 3CD_4+4Al(OD)_3` |
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| 32. |
Knowing the properties of H_2O and D_2O . Do you think that D_2O can be used for drinking purpose? |
| Answer» SOLUTION :`D_2O` dose not SUPPORT life because it slow down the REACTIONS in plants and animals. | |
| 33. |
KMnO_(4)underset(R.A.)overset(H^(+))toMn^(x) KMnO_(4)underset(R.A.)overset(OH)toMn^(y) |
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Answer» `K_(2)Cr_(2)O_(7)overset(OH)toCr^(Z)` |
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| 34. |
KMnO_(4) solution is to be standardised by titration against As_(2)O_(3) (s). A 0.1097 g sample of As_(2)O_(3) requires 26.10 mL of the KMnO_(4) solution for its titration. What are the molarity and normality of the KMnO_(4) solution (Mol. Wt. of As=75) |
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Answer» Solution :`Mn^(7+)+5e to Mn^(2+) ("REDUCTION")` `As_(2)^(3+) to 2As^(5+) +4e ("reduction")` Meq. Of `As_(2)O_(3)="Meq. Of KMnO_(4)` `[0.1097//(198//4)] xx 1000=26.10 xx N` `[E_(A) S_(2)O_(3))=M//4]` `N_(KMnO_(4))=0.085, M_(KMnO_(4)=0.085//5=0.017` by MOLE concept method `As_(2)OVERSET(+3)(O_(3)) to 2 overset(+5)(As)` n-factor =2|5-3|=+4 `[overset(+3)(As_(2)) to 2 overset(+5)(As)+4e^(-)] xx 5` `[overset(+7)(Mn)+5e^(-) to overset(+2) (Mn)]xx 4` `5 overset(+3)(As_(2))+4 overset(+7)(Mn) to 10 overset(+5)(As)+4 overset(+2)(Mn)` 5 mole 4 mole 5 mole of `As_(2)^(+3) "require to "4 mole of "KMnO_(4)` thus, 1 mole require to `4/5" mole of KMnO"_(4)` thus, `(0.1097)/(198) "mole require "to " mole "KMnO_(4)` Thus, molarity of `KMnO_(4)= 4/5 xx (0.1097)/(198 xx (26.10//1000))=0.017M` i,e, `N=M xx n-"factor"` `N=0.017 xx 5=0.085N` |
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| 35. |
KMnO_(4) solution is to be standaridised by titration against AsO_(3)(s). A 0.1097gsample of As_(2)O_(3) requires26.10mL of the solution for its titration. What are the molarity and normally of the KMnO_(4) solution? |
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Answer» |
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| 36. |
KMnO_(4) reacts with oxalic acid according to the equation, 2MnO_(4)^(-)+5C_(2)O_(4)^(2-)+16H^(+)to 2Mn^(2+)+10CO_(2)+8H_(2)O Here, 20 mL of 0.1 M KMnO_(4) is equivalent to : |
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Answer» 120 mL of 0.25M `H_(2)C_(2)O_(4)` `(0.1xx20)/(2)=(M_(2)V_(2))/(5)` `M_(2)V_(2)=5` It is POSSIBLE in the option c |
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| 37. |
KMnO_(4) reacts with oxalic acid according to the reaction : 2KMnO_(4) +5C_(2)O_(4)^(2-)+16 H^(+) to 2Mn^(2+) + 10 CO_(2) + 7H_(2)O Then, 20 mL of 0.1M KMnO_(4) is equivalent to : |
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Answer» 30 mL of 0.5 M `C_(2)H_(2)O_(4)` (oxalic acid) `(0.1xx20)/(2)=(M_(2)V_(2))/(5)` `M_(2)V_(2)=5` (It is possible in case of b.) |
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| 38. |
KMnO_4oxidizes X^(n+)to XO_3^(-)and it self changing to Mn+2is acid medium 2.68xx10^(-3) moles of requires mole of. The value of .n. is |
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Answer» |
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| 39. |
KMnO_(4) oxidizes X^(n+) ion to XO_(3)^(-) itself changing to Mn^(2+) in acid solution. 2.68xx10^(-3) moel of K_(2)Cr_(2)O_(7) was required 1.61xx10^(-3) mole of MnO_(4)^(-). What is the value of n ? Also calcualtethe atomic mass of X, if the weight of 1g equivalent of XCl_(n) is 56 |
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Answer» |
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| 40. |
KMnO_(4) reacts with KI,in basic medium to form I_(2) and MnO_(2)When 250 mL of 0.1M KI solution is mixed with 250 mL of 0.02 M KMnO_(4), in basic medium, what is the number of moles of I_(2) formed? |
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Answer» 0.015 |
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| 41. |
KMnO_(4) oxidises NO_(2)^(-) to NO_(3)^(-) in basic medium. How many moles ofNO_(2)^(-) are oxidised by 1 mol of KMnO_(4)? |
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Answer» |
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| 42. |
KMnO_(4) and K_(2)Cr_(2)O_(7) are replaced in volumetric analysis by |
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Answer» LA(III) salts |
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| 43. |
KMnO_4acts as an oxidising agent in alkaline medium, when alkaline KMnO_4is treated with KI, iodine ion is oxidised to |
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Answer» `I_2` |
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| 44. |
KMnO_(4) acts as an oxidising agent in alkaline medium when alkaline KMn_(4) is treated with KI iodide ion is oxidised to |
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Answer» `I_(2)` or `I^(-)+6OH^(-)rarrIO_(3)^(-)+3H_(2)O+6e^(-)` |
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| 45. |
Kjeldahl's method for estimation of nitrogen is not applicable to: |
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Answer» pyridine |
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| 46. |
Kjeldahl's method cannot be used for the estimationof nitrogen in |
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Answer» Pyridine |
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| 47. |
Kjeldahl's method cannot be used for estimation of nitrogen in: (I) C_(6)H_(5)CONH_(2) (II) Pyridine (III) C_(6)H_(5)-N=N-C_(6)H_(5) (IV) C_(6)H_(5)NHCOCH_(3) |
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Answer» I,II |
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| 48. |
Kjeldhal.s method cannot be used for the estimation of nitrogen in |
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Answer» Nitrobenzene |
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| 49. |
Kjeldahl's method cannot be used for the estimation of nitrogen in |
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Answer» Nitrobenzene |
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