52671 + Interview Questions in Chemistry in Class 11

1.	If the heats of formation of Al_2O_3 and Fe_2O_3 are -400 K.Cal and -190 K.Cal respectively, the heat of the following reaction is 2Al + Fe_2O_3 rarr 2Fe + Al_2O_3
Answer» `590 K.Cal` `-210 K.Cal` `-290 K.Cal` `210 K.Cal` ANSWER :D

Discussion

2.	If the half reaction A + E^(-) rarr A^(-)moves in the backward reaction what does half reaction mean
Answer» SOLUTION :It MEANS that `A^(-)` is READILY oxidised

Discussion

3.	If the half cell reactions ae given as (i)Fe^(2+)(aq)+2e^(-) rarrFe(s),E^(@)=-0.44 V (ii)23H^(+) (aq)+1//2O_(2)(g)+2e^(-)rarrH_(2)O(l),E^(@)=+1.23V The E^(@) for the reaction Fe(s)+2H^(+)(aq)+1//2 O_(2) (g) rarr Fe^(2+) (aq)+H_(2)O (l) is
Answer» `1.67 V` `-1.67 V` `+0.79 V` `-0.79 V` ANSWER :B

Discussion

4.	If the greenhouse effcct or global warming remains unchecked, it alter :
Answer» SEA, levels ozone LAYER rainfall temperature ANSWER :A::C::D

Discussion

5.	If the graph is plotted for 1 mole gas in such a way that PV is plotted against 'P', then intercept of the graph for real gas will be:
Answer» `RT + PB + a` `RT` `RT - Pb + a` `RT + Pb + AB + a` ANSWER :B

Discussion

6.	If the four tubes of a car are filled to the same pressure with N_(2),O_(2)H_(2) and Ne separately, then which one will be filled first ?
Answer» `N_(2)` `O_(2)` `H_(2)` Ne Answer :A::B::C::D

Discussion

7.	If the following reactions, (a) CH_(3)-overset(CH_(3))overset(\|)(CH)-underset(OH)underset(\|)(CH)-CH_(3)overset(H^(+)//"Heat")rarr underset((("Major"),("product")))(A)+underset((("Major"),("product")))(B) (b) A underset("in absence of peroxide")overset("HBr, dark")rarr underset((("Major"),("product")))(C)+underset((("Major"),("product")))(D) the major products (A) and (C) arerespecticvely:
Answer» `CH_(3)-overset(CH_(3))overset(\|)(C)-CH-CH_(3)` and `CH_(3)-overset(CH_(3))overset(\|)(CH)-underset(Br)underset(\|)(CH)-CH_(3)` `CH_(2)=overset(CH_(3))overset(\|)(C)-CH_(2)-CH_(3)` and `CH_(3)-underset(Br)underset(\|)overset(CH_(3))overset(\|)(C)-CH_(2)-CH_(3)` `CH_(2)=overset(CH_(3))overset(\|)(C)-CH_(2)-CH_(3)` and `underset(Br)underset(\|)(CH_(2))-overset(CH_(3))overset(\|)(CH)-CH_(2)-CH_(3)` `CH_(3)-overset(CH_(3))overset(\|)(C)=CH-CH_(3)` and `CH_(3)-underset(Br)underset(\|)overset(CH_(3))overset(\|)(C)-CH_(2)-CH_(3)` Solution :`CH_(3)-overset(CH_(3))overset(\|)(CH)-underset(OH)underset(\|)(CH)-CH_(3)overset(H^(+)//Delta)rarr CH_(3)-overset(CH_(3))overset(\|)(CH)-overset(+)(CH)-CH_(3) overset("1,2-Hydride shift")rarr CH_(3)-underset(+)overset(CH_(3))overset(\|)(C)-CH_(2)-CH_(3)overset(-H^(+))rarr underset("Major (A)")(CH_(3)-overset(CH_(3))overset(\|)(C)=CH-CH_(3))+underset("Minor (B)")(CH_(2)=overset(CH_(3))overset(\|)(C)-CH_(2)-CH_(3))underset((A))(CH_(3)-overset(CH_(3))overset(\|)(C)=CH-CH_(3))underset("Dark in the ABSENCE of peroxide")overset(HBR)rarr CH_(3)-underset(Br)underset(\|)overset(CH_(3))overset(\|)(C)-CH_(2)-CH_(3)`

Discussion

8.	If the formation of diatomic boron molecule is predicted based on MO theory, the bond order would be
Answer» 0.5 1 1.5 12 Answer :B

Discussion

9.	If the [F^-] = 2.0 xx 10^(-5) M in water. Then, how many gram of CaCl_2 will be added for precipitation of F^-? K_(sp) for CaF_2 = 1.7 xx 10^(-10). (Molecular mass of CaCl_2 = 111 "g mol"^(-1))
Answer» SOLUTION :More than 47.175 GM of `CaCl_2`is to be ADDED

Discussion

10.	If the equilibrium constant for the reaction, H_(2)(g)+I_(2) Leftrightarrow 2HI(g) is K. What is the equilibrium constant of HI(g) Leftrightarrow 1/2 H_(2) (g)+1/2 I_(2) (g)?
Answer» Solution :`H_(2) (G)+I_(2) (g) LEFTRIGHTARROW 2HI(g), K` `K=([HI]^(2))/([H_(2)] [I_(2)]) .......(1)` For the REACTION, `HI(g) Leftrightarrow 1/2 H_(2) (g)+1/2 I_(2) (g)` equilibrium CONSTANT. `K.=([H_(2)]^(1//2) [I_(2)]^(1//2))/([HI]) ""K.=(1)/(K^(1//2))=(1)/sqrtK`

Discussion

11.	If the equilibrium constant for the reaction H^+(aq)+OH^-)(aq)iffH_2O(l) is 10^13 at certain temperature then what is the E^(@) for the reaction, 2H_2O(l)+2e^-)iffH_2(g)+2OH^(-)(aq)
Answer» 4.74V 0.547V 4.37V 1.09V Answer :B

Discussion

12.	If the equlibrium constant for the reaction of weak acid HA with strong base is 10^(9) then calculate the pH of 0.1 M NaA.
Answer» SOLUTION :`K_n =10 ^(9), K_h =(1)/( K_n)= 10 ^(9) ` ` K_a =(K_W)/( K_h)= 10 ^(-5) rArr PH =7 +(P^(K_a))/( 2) + (1)/(2) LOG C ` ` =7 +(5)/(2) +(1)/(2) log 10 ^(-1)= 9`

Discussion

13.	If the equilibrium constant for the reaction 0.125. P_(4(g))+6Cl_(2(g))hArr4PCl_(3(g)) The value of equilibrium for this reaction
Answer» `0.25` `8` `0.125` `6` SOLUTION :N//A

Discussion

14.	If the equilibrium constant for N_(2(g))+O_(2(g))hArr2NO_((g)) is K, the equilibrium constant for 1/2N_(2(g))+1/2O_(2(g))hArrNO_((g))will be
Answer» K `K^(2)` `K^(1//2)` `1/2K` Solution :Since REACTANTS and PRODUCED are REDUCED to half of its VALUE, therefore K also BECOMES `K^(1//2)`

Discussion

15.	If the equilibrium constant for N_(2(g))+ O_(2(g)) hArr 2NO_((g)) is K, the equilibrium constant for 1/2N_(2(g)) + 1/2O_(2(g)) hArr NO_((g)) will be :
Answer» K `K^2` `K^(1//2)` `1/2K` SOLUTION :`N_(2(G)) + O_(2(g)) hArr 2NO_((g)) , K` `1/2N_(2(g)) + 1/2O_(2(g)) hArr NO_((g)) , K.` when a reaction is multiplied by 1/2 then `K.=(K)^(1//2)`

Discussion

16.	If the equilibrium constant for N_(2) (g) + O_(2) (g) hArr 2 NO (g) " is " K, the equilibrium constant for 1/2 N_(2) (g) + 1/2 O_(2) (g) hArr NO (g) " will be "
Answer» `1/2K` K `K^(2)` `K^(1//2)` Solution :When a REACTION is dividend by 2 , new equilibrium constant (K') is square root of the equilibrium constant (K) of the given reaction , i.e., new `K' = SQRT(K)= K^(1//2).`

Discussion

17.	If the enthalpy of water is 386 kJ, entropy of water is .......... .
Answer» `0.5 KJ` `1.3 kJ` `1.5 kJ` `22.05 kJ` SOLUTION :`DELTA S_("vap") = (Delta H)/( T) = (386)/( 298) = 1.3` kJ

Discussion

18.	If the enthalpy of combustion of diamond and graphite are -395.4kJ mol^(-1) and -393.6 kJ mol^(-1) what is the enthalpy change for the C (graphite) rarr C (diamond) conversion ?
Answer» Solution :C(diamond) `+O_(2)(g) rarr CO_(2)(g) Delta= -395.4 kJ MOL^(-1)` C (graphite) `+ O_(2)(g) rarr CO_(2)(g)Delta H = -393.6 kJ mol^(-1)` …(2) C (graphite) `rarr "C(diamond)"_(1)` substracting (1) from (2), we GET C (graphit) `rarr "C(diamond)" DeltaH = -393.6 kJ - (-395.4 kJ)`, `Delta H = +1.8 kJ mol^(-1)`.

Discussion

19.	If the enthalpy change for the transition of liquid water to steam is 30 kJ mol^(-1) at 27^(@)C, the entropy change for the process would be
Answer» `100 J MOL^(-1)K^(-1)` `10J mol^(-1) K^(-1)` `1.0 J mol^(-1) K^(-1)` `0.1 J mol^(-1) K^(-1)` Solution :`DeltaS_("VAP") = (Delta_("vap") H)/(T)`

Discussion

20.	If the enthalpy change for the transition of liquid water to steam is 30 kJ/mol""^(-1) at 27°C, the entropy change for the process would be :
Answer» 10 J mol`""^(-1) K^(-1)` 1.0 J mol`""^(-1) K^(-1)` 0.1 J mol`""^(-1) K^(-1)` 100 J mol`""^(-1) K^(-1)` Solution :Given `DELTA H = 30` KJ mol`""^(-1) T = 273+ 27 = 300` K `Delta S_(T) = (Delta H_(T) )/( 300) "J mol"^(-1)` `= 100"J mol"^(-1) K^(-1)`

Discussion

21.	Ionisation of energy of F^(-) is 320 kJ mol^(-1) . The electron gain enthalpy of fluorine would be
Answer» `10 J mol ^(-1) K ^(-1)` `1.0 J mol ^(-1) K ^(-1)` `0.1 J mol ^(-1) K ^(-1)` `100 J mol ^(-1) J ^(-1)` Answer :D

Discussion

22.	If the energy of an electron in the second Bohr orbit of H-atom is -E , what is the energy of the electrons in the Bohr's first orbit?
Answer» 2E `-4E` `-2E` `4E` ANSWER :B

Discussion

23.	If the energy difference between two electronic states is 214.68 kJ mol^(-1), calculate the frequency of light emitted when an electron drops from the higher to the lower state. Planck's constant, h = 39.79 xx 10^(-14)kJ sec mol^(-1)
Answer» SOLUTION :`Delta E = hv`, i.e., `(214.68 KJ MOL^(-1)) = (39.79 XX 10^(-14)kJsec mol^(-1)) v or v = 5.395 xx 10^(14) s^(-1)`

Discussion

24.	Energy required to dissociate 4g of gaseous hydrogen into free gaseous atoms is 208Kcal at 25^(@)C The bond energy of H-H bond will be
Answer» 104 KCAL 52 kcal 520 kcal 5.2 kcal ANSWER :A

Discussion

25.	If the energy of an electron in 3rd Bohr orbit is -E, what is the energy of the electron in (i) 1stBohr orbit (ii) 2nd Bohr orbit ?
Answer» Solution :`E_(N) PROP (1)/(n^(2)) :. E_(3) prop (1)/(3^(2)) , " i.e., " E_(3) prop (1)/(9), E_(2) prop (1)/(2^(2)), " i.e., " E_(2) prop (1)/(4), E_(1) prop (1)/(1^(2))` `:. (E_(3))/(E_(1)) = (1)/(9) :. E_(1) = 9 E_(3) = - 9E "" ( :' E_(3) = -E)` `(E_(3))/(E_(2)) = (4)/(9) :. E_(2) = (9)/(4) E_(3) = - (9)/(4) E = -2.25 E`

Discussion

26.	If the electronic configuration of nitrogen had 1s^(7), it would have energy lower than that of the normal ground state configuration 1s^(2)2s^(2)2p^(3) because the electrons would be closer to the nucleus. Yet 1s^(7) is not observed because it vilates:
Answer» Heisenberg UNCERTAINTY principle Hund's rule Pauli's exclusion principle Bohr postulates of STATIONARY orbits Answer :C

Discussion

27.	If the electronic structure of oxygen atom is written as 1s^2 , 2s^2 it would violate
Answer» Hund.s rule Paulis exclusion PRINCIPLE Both Hund.s and Pauli.s principles Aufbau.s principle SOLUTION :Hund.s rule says about degenerate orbitals filled with SINGLE `e^-` each.

Discussion

28.	If the electronic configuration of an element is 1s^(2) 2s^(2) 2p^(6) 3s^(2) 3p^(6) 3d^(2) 4s^(2), the four electrons involved in chemical bond formation will be
Answer» `3p^(6)` `3p^(6) , 4s^(2)` `3p^(6), 3D^(2)` `3d^(2) , 4s^(2)` Solution :`3d^(2), 4s^(2)` The given electronic configuration indicate that an element is vanadium (Z = 22). It BELONGS to d-block of the periodic table. In transition elements i.e., d-block elements, electrons of ns and (n - l)d subshell take part in BOND formation.

Discussion

29.	The electronegativity values according to Mulliken scale are _____times to those in Pauling scale
Answer» Solution :Electronegativity in MULLIKEN SCALE is 2.8 TIMES GRATER than Pauling scale values. So the value of Electronegativity `= 2.8 xx 4 =11.2`

Discussion

30.	If the electron of the hdyrogen atom is replaced by another particle of same charge but of the double mass, then :
Answer» radii of different shells will increase energy gap between two LEVELS will BECOME DOUBLE ionization energy of the ATOM will be double speed of new particle in a shell will be LESSER than the speed of electron in the same shell Solution :I.E `= +(2pi^2 mz^2 e^4)/(n^2 h^2)` When mass becomes double , the ionization energy will be double.

Discussion

31.	If the electronic configuration of an element is1s^(2) 2s^(2)2p^(6) 3s^(2) 3p^(6)3d^(2) 4s^(2)thefour electrons involved in chemical bond formation will be………….. .
Answer» `3p^(6)` `3p^(6), 4S^(2)` `3p^(6), 3d^(2)` `3d^(2) , 4s^(2)` SOLUTION :In transition elements ,i.e. d-block elements , electrons of ns ans (n-1) d subshells take PART in bond FORMATION.

Discussion

32.	If the electron in hydrogen atom jumps from the third orbit to second orbit, the wavelength of the emitted radiation is given by lambda = (36)/(xR) . Then value of x is
Answer» SOLUTION :`1/(lambda) = R[1/(n_1^2) - 1/n_2^2 ] = R [1/2^2 - 1/(3^2)]` `1/(lambda) = (5R)/(36) THEREFORE lambda = (36)/(5R)`

Discussion

33.	If the electron of a hydrogen atom is present in the first orbit. The total energy of the electrons is
Answer» `(-E^(2))/(R )` `(-e^(2))/(r^(2))` `(-e^(2))/(2R )` `(-e^(2))/(2r^(2))` Answer :C

Discussion

34.	If the edge length of a NaH unit cell is 488 pm, what is the length of Na-H bond if it crystallises in the fcc structure ?
Answer» 122 pm 244 pm 488 pm 976 pm Solution :NaH has fcc structure SIMILAR to that of NACL. Thus, edge length of NaH=`2(r_(Na^+)+(r_H^(-))` i.e., `2(r_(Na^+)+r_(H^-))`=488 pm `THEREFORE r_(Na^+)+r_(H^-)`=244 pm, which is Na-H BOND length

Discussion

35.	If the E_("cell")^(@) for a given reaction has a negative value, which of the following gives the correct relationships for the values of Delta G^(@) and K_(eq) ?
Answer» `DELTA G^(@) lt 0, K_(EQ) gt 1` `Delta G^(@) lt 0, K_(eq) lt 1` `Delta G^(@) gt 0, K_(eq) lt 1` `Delta G^(@) gt 0, K_(eq) gt 1` Solution :`E_("cell")^(@) = -ve` `Delta G^(@) = -nF " "E_("cell")^(@)` `Delta G^(@) =+ve rArr Delta G gt 0` `Delta G^(@) = -2.303 " RT LOG "K_(eq)` `therefore K_(eq) lt 1`

Discussion

36.	If the distance between Na^(+) and Cl^(-) ions in sodium chloride crystal is X pm, the length of the edge of the unit cell is
Answer» 4X pm X/4 pm X/2 pm 2X pm SOLUTION :In NaCl EDGE LENGTH, (a) `= 2xx` distance between `Na^(+)` and `CL^(-)` = 2X .

Discussion

37.	If the distance between Na^(+)and Cl^(-)ions in sodium chloride crystal is X pm, the length of the edge of the unit cell is
Answer» 4X pm `X//4"pm"` `X//2"pm"` `2X"pm"` SOLUTION :In `Na^(+)VL^(-)`CRYSTAL, Edge LENGTH of UNIT cell =`2times"Distance between" Na^(+) and Cl^(-)`ion 2X pm

Discussion

38.	If the % dissociation of N_(2) O_(4) is 50 , the ratio of Kp and P_(eq) for N_(2) O_(4) hArr 2 NO_(2) becomes equal to
Answer» `3//4` `3//8` `4//3` `4//9` ANSWER :C

Discussion

39.	If the dispersed phase is a liquid and the dispersion medium is a solid, the colloid is known as:-
Answer» A sol An emulsion A GEL A foam Solution :`UNDERSET(("DISPERSED phase"))("LIQUID")+underset(("Dispersion medium"))("Solid")=underset(("Colloid"))(Gel)` (e.g. butter)

Discussion

40.	If the difference in the level of Hg in an open arm manometer (One end open to atmosphere and other end is connected to gas chamber) is 6 mm. then what can be the pressure of gas? (Given: 1 atm=1.01325xx 10^(5)N//m^(2))
Answer» 765mm of Hg 755 MM of Hg 765 torr 700torr Answer :ABC

Discussion

41.	if thediameter of atomis 0.15nmcalculatethe number ofcarbon atom whichcan beplacedsideby sidein astraightline across lengthof scaleof length20 cm long
Answer» Solution :20 CM = 20`XX 10^(7)NM`length diameterof carbonatom=0.15 nm So0.15nm space= 1carbon atom 20`xx 10^(7) nm` space = (?)carbon atom Noof carbon atoms = `(20 xx 10^(7)nm xx 1)/(0.15 nm) ` =133.3`xx10^(7)` `1.333 xx 10^(9)`CARBONATOMS

Discussion

42.	If the diameter of a carbon atom is 0.15 nm, calculate the number of carbon atoms which can be placed side by side in a straight line across the length of scale of length 20 cm long.
Answer» Solution :Diameter of CARBON atom `= 0.15 NM = 0.15 xx 10^(-9) m = 1.5 xx 10^(-10)m` Length along which ATOMS are to be placed `= 20 cm = 20 xx 10^(-2) m = 2 xx 10^(-1)m` `:.` No. of C-atoms which can be placed along the line `= (2 xx 10^(-1))/(1.5 xx 10^(-10)) = 1.33 xx 10^(9)`

Discussion

43.	If the density of gas at sea level is 1.5 mg L^(-1), find the density of that gas on Mount Abu, having pressure 0.5 bar.(formula (d_(1))/(d_(2))=(p_(1))/(p_(2)))
Answer» ANSWER :`0.75 MG L^(-1)`

Discussion

44.	If the density of methanol is 0.793 kg L^(-1), what is its volume needed for making 2.5 L of its 0.25 M solution ?
Answer» Solution :DENSITY `= 0.793 Kg//L = 0.793 xx 10^(3) gm//L` Final volume `= 2.5 L = V_(2)` final molarity `= 0.25M = M_(2)` Molecular mass of METHANOL `(CH_(3)OH)` `= (1xx12.01) + 4 (1.0079) + 16.00` `= 32.0416 ~= 32` gm/mol Molarity `= ("Density")/("Molecular mass") = (0.793xx10^(3) gm//L)/(32 gm//L)` `=24.781` mol/L `M_(1)V_(1) = M_(2)V_(2)` `:.24.781xxV_(1) = 0.25xx2.5` `:.V_(1)=(0.25xx2.5)/(24.781)=0.02522 L = 25.22` ML

Discussion

45.	If thedensity of a gas at the sea level at 0^(@)C is 1.29 kg m^(-3), what will be its molar mass ? (Assume that pressure is equal to 1 bar).
Answer» Solution :`M=(dRT)/(P)=(1.29 kg m^(-3)xx8.314N m K^(-1) MOL^(-1)xx273 K)/(1.0xx10^(5)N m^(-2))=0.0293 kg mol^(-1)=29.3 g mol^(-1)`(1J=1 N m)

Discussion

46.	If the density of a solution is 3.12 g mL^(-1), the mass of 1.5 mL solution in significant figures is .........
Answer» 4.7 g `4680xx10^(-3)` g 4.680 g 46.80 g SOLUTION :DENSITY of solution `= 3.12 g mL^(-1)` (GIVEN) Volume of solution `= 1.5` mL For a solution, Mass `= "volume" xx "density` `= 1.5 mL xx 3.12 g mL^(-1)= 4.68g` The DIGIT 1.5 has only two significant figures, figures, so the answer must also be limited to two significant figures. So, it is rounded off to reduce the number of significant figures. Hence, the answer is reported as 4.7 g.

Discussion

47.	If the DeltaG^@ lt0, then what is the value of -DeltaG^@//RT ?
Answer» Zero Positive Negative All ANSWER :B

Discussion

48.	If the degree of ionization (dissociation) of weak acid is alpha , then write the equation of ionization constat.
Answer» SOLUTION :`K_a=(C alpha^2)/(1-alpha)`

Discussion

49.	If the degree of dissociation of PCl_(5 (g)) at certain temperature and equilibrium is 3/4 , VD of PCl_(5) at same temperature is nearly (M.W. of PCl_(5) = 208.5)
Answer» 60 70 75 50 Answer :A

Discussion

50.	If the de Broglie wavelength of a particle of mass m is 100 times its velocity, then its value in terms of its mass (m) and Planck's constant (h) is
Answer» `(1)/(10) sqrt((m)/(h))` `10 sqrt((h)/(m))` `(1)/(10) sqrt((h)/(m))` `10 sqrt((m)/(h))` Solution :Suppose velocity `(V) = X` Then DE Broglie wavelength `(LAMDA) = 100x` Now, `lamda =(h)/(mv) " " :.100x = (h)/(MX)` or `x^(2) = (1)/(100) (h)/(m) or x = (1)/(10) sqrt((h)/(m))` Hence, `lamda = 100x = 10 sqrt((h)/(m))`

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

If the heats of formation of Al_2O_3 and Fe_2O_3 are -400 K.Cal and -190 K.Cal respectively, the heat of the following reaction is 2Al + Fe_2O_3 rarr 2Fe + Al_2O_3

If the half reaction A + E^(-) rarr A^(-)moves in the backward reaction what does half reaction mean

If the half cell reactions ae given as (i)Fe^(2+)(aq)+2e^(-) rarrFe(s),E^(@)=-0.44 V (ii)23H^(+) (aq)+1//2O_(2)(g)+2e^(-)rarrH_(2)O(l),E^(@)=+1.23V The E^(@) for the reaction Fe(s)+2H^(+)(aq)+1//2 O_(2) (g) rarr Fe^(2+) (aq)+H_(2)O (l) is

If the greenhouse effcct or global warming remains unchecked, it alter :

If the graph is plotted for 1 mole gas in such a way that PV is plotted against 'P', then intercept of the graph for real gas will be:

If the four tubes of a car are filled to the same pressure with N_(2),O_(2)H_(2) and Ne separately, then which one will be filled first ?

If the formation of diatomic boron molecule is predicted based on MO theory, the bond order would be

If the [F^-] = 2.0 xx 10^(-5) M in water. Then, how many gram of CaCl_2 will be added for precipitation of F^-? K_(sp) for CaF_2 = 1.7 xx 10^(-10). (Molecular mass of CaCl_2 = 111 "g mol"^(-1))

If the equilibrium constant for the reaction, H_(2)(g)+I_(2) Leftrightarrow 2HI(g) is K. What is the equilibrium constant of HI(g) Leftrightarrow 1/2 H_(2) (g)+1/2 I_(2) (g)?

If the equilibrium constant for the reaction H^+(aq)+OH^-)(aq)iffH_2O(l) is 10^13 at certain temperature then what is the E^(@) for the reaction, 2H_2O(l)+2e^-)iffH_2(g)+2OH^(-)(aq)

If the equlibrium constant for the reaction of weak acid HA with strong base is 10^(9) then calculate the pH of 0.1 M NaA.

If the equilibrium constant for the reaction 0.125. P_(4(g))+6Cl_(2(g))hArr4PCl_(3(g)) The value of equilibrium for this reaction

If the equilibrium constant for N_(2(g))+O_(2(g))hArr2NO_((g)) is K, the equilibrium constant for 1/2N_(2(g))+1/2O_(2(g))hArrNO_((g))will be

If the equilibrium constant for N_(2(g))+ O_(2(g)) hArr 2NO_((g)) is K, the equilibrium constant for 1/2N_(2(g)) + 1/2O_(2(g)) hArr NO_((g)) will be :

If the equilibrium constant for N_(2) (g) + O_(2) (g) hArr 2 NO (g) " is " K, the equilibrium constant for 1/2 N_(2) (g) + 1/2 O_(2) (g) hArr NO (g) " will be "

If the enthalpy of water is 386 kJ, entropy of water is .......... .

If the enthalpy of combustion of diamond and graphite are -395.4kJ mol^(-1) and -393.6 kJ mol^(-1) what is the enthalpy change for the C (graphite) rarr C (diamond) conversion ?

If the enthalpy change for the transition of liquid water to steam is 30 kJ mol^(-1) at 27^(@)C, the entropy change for the process would be

If the enthalpy change for the transition of liquid water to steam is 30 kJ/mol""^(-1) at 27°C, the entropy change for the process would be :

Ionisation of energy of F^(-) is 320 kJ mol^(-1) . The electron gain enthalpy of fluorine would be

If the energy of an electron in the second Bohr orbit of H-atom is -E , what is the energy of the electrons in the Bohr's first orbit?

If the energy difference between two electronic states is 214.68 kJ mol^(-1), calculate the frequency of light emitted when an electron drops from the higher to the lower state. Planck's constant, h = 39.79 xx 10^(-14)kJ sec mol^(-1)

Energy required to dissociate 4g of gaseous hydrogen into free gaseous atoms is 208Kcal at 25^(@)C The bond energy of H-H bond will be

If the energy of an electron in 3rd Bohr orbit is -E, what is the energy of the electron in (i) 1stBohr orbit (ii) 2nd Bohr orbit ?

If the electronic configuration of nitrogen had 1s^(7), it would have energy lower than that of the normal ground state configuration 1s^(2)2s^(2)2p^(3) because the electrons would be closer to the nucleus. Yet 1s^(7) is not observed because it vilates:

If the electronic structure of oxygen atom is written as 1s^2 , 2s^2 it would violate

If the electronic configuration of an element is 1s^(2) 2s^(2) 2p^(6) 3s^(2) 3p^(6) 3d^(2) 4s^(2), the four electrons involved in chemical bond formation will be

The electronegativity values according to Mulliken scale are _____times to those in Pauling scale

If the electron of the hdyrogen atom is replaced by another particle of same charge but of the double mass, then :

If the electronic configuration of an element is1s^(2) 2s^(2)2p^(6) 3s^(2) 3p^(6)3d^(2) 4s^(2)thefour electrons involved in chemical bond formation will be………….. .

If the electron in hydrogen atom jumps from the third orbit to second orbit, the wavelength of the emitted radiation is given by lambda = (36)/(xR) . Then value of x is

If the electron of a hydrogen atom is present in the first orbit. The total energy of the electrons is

If the edge length of a NaH unit cell is 488 pm, what is the length of Na-H bond if it crystallises in the fcc structure ?

If the E_("cell")^(@) for a given reaction has a negative value, which of the following gives the correct relationships for the values of Delta G^(@) and K_(eq) ?

If the distance between Na^(+) and Cl^(-) ions in sodium chloride crystal is X pm, the length of the edge of the unit cell is

If the distance between Na^(+)and Cl^(-)ions in sodium chloride crystal is X pm, the length of the edge of the unit cell is

If the % dissociation of N_(2) O_(4) is 50 , the ratio of Kp and P_(eq) for N_(2) O_(4) hArr 2 NO_(2) becomes equal to

If the dispersed phase is a liquid and the dispersion medium is a solid, the colloid is known as:-

If the difference in the level of Hg in an open arm manometer (One end open to atmosphere and other end is connected to gas chamber) is 6 mm. then what can be the pressure of gas? (Given: 1 atm=1.01325xx 10^(5)N//m^(2))

if thediameter of atomis 0.15nmcalculatethe number ofcarbon atom whichcan beplacedsideby sidein astraightline across lengthof scaleof length20 cm long

If the diameter of a carbon atom is 0.15 nm, calculate the number of carbon atoms which can be placed side by side in a straight line across the length of scale of length 20 cm long.

If the density of gas at sea level is 1.5 mg L^(-1), find the density of that gas on Mount Abu, having pressure 0.5 bar.(formula (d_(1))/(d_(2))=(p_(1))/(p_(2)))

If the density of methanol is 0.793 kg L^(-1), what is its volume needed for making 2.5 L of its 0.25 M solution ?

If thedensity of a gas at the sea level at 0^(@)C is 1.29 kg m^(-3), what will be its molar mass ? (Assume that pressure is equal to 1 bar).

If the density of a solution is 3.12 g mL^(-1), the mass of 1.5 mL solution in significant figures is .........

If the DeltaG^@ lt0, then what is the value of -DeltaG^@//RT ?

If the degree of ionization (dissociation) of weak acid is alpha , then write the equation of ionization constat.

If the degree of dissociation of PCl_(5 (g)) at certain temperature and equilibrium is 3/4 , VD of PCl_(5) at same temperature is nearly (M.W. of PCl_(5) = 208.5)

If the de Broglie wavelength of a particle of mass m is 100 times its velocity, then its value in terms of its mass (m) and Planck's constant (h) is