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Engineering
1199 Views   |

Sulphide ions in alkaline solution react with solid sulphur to form polyvalent sulphide ions. The equikibrium constant for the formation of C and S32- from S and S2- ions are 1.7 and 5.3 respectively. Equilibrium constant for the formation of S32-   from  S32-  and S is

• Option 1)

1.33

• Option 2)

3.11

• Option 3)

4.21

• Option 4)

1.63

As we learnt in Law of Chemical equilibrium - At a given temperature, the product of concentration of the reaction products raised to the respective stoichiometric coefficient in the balanced chemical equation divided by the product of concentration of the reactants raised to their individual stoichiometric coefficients has a constant value. - wherein are equilibrium concentration     Given...
Engineering
281 Views   |

Which species acts as stronger acid than formic acid in aqueous solution?

• Option 1)

CH3COOH

• Option 2)

H2SO4

• Option 3)

$NH_{4}^{+}$

• Option 4)

$HPO_{4}^{2-}$

As learnt in Ionization constant of weak acids - Consider    - wherein     The strength of an acid is determined by the stability of its conjugate base.  has more delocalization of -ve charge than  and is more stable So  is stronger acid than  Option 1) CH3COOH This solution is incorrect Option 2) H2SO4 This solution is correct Option 3) This solution is incorrect Option 4) This...
Engineering
94 Views   |

Which is not amphoteric?

• Option 1)

$HSO_{4}^{-}$

• Option 2)

$HCO_{3}^{-}$

• Option 3)

$H_{2}PO_{4}^{-}$

• Option 4)

$HCOO^{-}$

As learnt in Ionization reaction of dibasic acid - - wherein    are called first and second ionization constant.   Of all the species given,  is the only one that cannot donate a proton and act as an acid. All of these can accept a proton thereby acting as a lease. Option 1) This solution is incorrect. Option 2) This solution is incorrect. Option 3) This solution is...
Engineering
180 Views   |

Which is correct w.r.t non-ideal solution?

• Option 1)

Solution obeys Raoult's Law over the entire range of concentration.

• Option 2)

The vapour pressure is always higher than that predicted by Raoult's Law

• Option 3)

The cause for the deviations lie in the nature of interactions at the molecular level

• Option 4)

All of these

As learnt in Condition for positive deviation - When A - A interactions and B - B  interactions  are  stronger than A - B interactions. e.g. Ethanol + water - wherein     Condition for negative deviation - When A - A interactions and B - B  interactions  are  weaker than A - B interactions. e.g. Acetone + Chloroform - wherein   Any solution that shows deviation from Raoult's law is...
Engineering
99 Views   |

When 20g of CaCO3 were put into 10 litre of flask and heated to 8000 C , 35% of CaCO3 remained unreacted at equlibrium. KP for decomposition of CaCO is :

• Option 1)

1.145 atm

• Option 2)

0.145 atm

• Option 3)

2.145 atm

• Option 4)

3.145 atm

As learnt in Equilibrium constant in gaseous system - For equilibrium involving gases, it is usually more convenient to express the equilibrium constant in terms of partial pressure.  - wherein The ideal gas equation is written as                        At t=0                  0.2 At equilibrium     0.2*0.35                        0.2* 0.65             0.2* 0.65     Option 1) 1.145...
Engineering
104 Views   |

What is the PH of a 1M CH3COONa? Ka of acetic acid=1.8x10-5,Kw=10-14 mol2/l2

• Option 1)

2.4

• Option 2)

3.6

• Option 3)

4.8

• Option 4)

9.4

As learnt in Ionization constant of weak acids - Consider    - wherein        or    Option 1) 2.4 This solution is incorrect Option 2) 3.6 This solution is incorrect Option 3) 4.8 This solution is incorrect Option 4) 9.4 This solution is correct
Engineering
123 Views   |

The mass of $AgNo_{3}$ present in 100 ml of its 0.25 Molar solution is

• Option 1)

4.25 g

• Option 2)

42.5 g

• Option 3)

17g

• Option 4)

1.7 g

As learnt in Molarity - -    moles of  in 100ml                                     mass    Option 1) 4.25 g This solution is correct Option 2) 42.5 g This solution is incorrect Option 3) 17g This solution is incorrect Option 4) 1.7 g This solution is incorrect
Engineering
106 Views   |

The von't Hoff factor for 0.1M Ba$(NO_{3})_{2}$ solution is 2.74. The degree of dissociation is

• Option 1)

91.3%

• Option 2)

74 %

• Option 3)

87%

• Option 4)

100%

As we learned in concept Vant Hoff factor for dissociation - Where is the no. of dissociated particles degree of association   - wherein     Option 1) 91.3% Incorrect Option 2) 74 % Incorrect Option 3) 87% Correct Option 4) 100% Incorrect
Engineering
432 Views   |

The values of Van't Hoff factors for KCl, NaCl, and K2SO4 are

• Option 1)

2,2,2

• Option 2)

2,2,3

• Option 3)

1,1,2

• Option 4)

1,1,1

As we discussed in concept Vant Hoff factor for dissociation - Where is the no. of dissociated particles degree of association   - wherein   All strong electrolytes will dissociate completely   Option 1) 2,2,2 Incorrect Option 2) 2,2,3 Correct Option 3) 1,1,2 Incorrect Option 4) 1,1,1 Incorrect
Engineering
155 Views   |

The unit of Ebulioscopic Contant is

• Option 1)

K Kg mol-1 or K(molality)-1

• Option 2)

mol Kg K-1  or K-1 (molality)

• Option 3)

Kg mol-1 K-1  or K-1 (molality)-1

• Option 4)

K Mol Kg-1 or K (molality)

Dependence of K_{b} -   depends only on nature of solvent. imp (Use value of R in accordance to unit of )     - wherein Boiling point of pure solvent in gm      Molar mass of solvent in gm = Enthalpy of vap R = Universal gas constant    We know Ebullioscopic Contant,  Where M= molar mass of solvent in gm K Kg mol-1 or K(molality)-1 Option 1) K Kg mol-1 or K(molality)-1 Correct Option...
Engineering
111 Views   |

The solubility products of Al(OH)and Zn(OH)2 are 8.5x10-23 and 1.8x10-14 respectively. If NH4OH is added to a solution containing Al3+ and Zn2+ ions, then substance precipitated first is

• Option 1)

Al(OH)3

• Option 2)

Zn(OH)2

• Option 3)

Both together

• Option 4)

None of these

As we learned in concept Solubility product constant - - wherein For a pure solid substance the concentration remain constant                             Given solubility products   Since solubility of  is lower than   and  will be participated first. Option 1) Al(OH)3 Correct Option 2) Zn(OH)2 Incorrect Option 3) Both together  Incorrect Option 4) None of these  Incorrect
Engineering
102 Views   |

The self ionisation constant for pure formic acid,$K=[HCOOH_{2}^{+}] [HCOO^{-}]$ has been estimated as 10-6 at 1.22g/cm3.

The percentage of formic acid molecules in pure formic acid converted to formate ion is

• Option 1)

0.002 percentage

• Option 2)

0.004 percentage

• Option 3)

0.006 percentage

• Option 4)

0.008 percentage

As we learned in concept Ionization constant of weak acids - Consider    - wherein      No. of moles of formic acid in one L of solution = % dissociation =   Option 1) 0.002 percentage  Incorrect Option 2) 0.004 percentage  Correct Option 3) 0.006 percentage  Incorrect Option 4) 0.008 percentage  Incorrect
Engineering
444 Views   |

The relative lowering of vaour pressure produced by dissolving 71.5 g of a substance in 1000 g of water is 0.00713. The molecular weight of the substance will be

• Option 1)

18.0

• Option 2)

342

• Option 3)

160

• Option 4)

180

As we learned in concept Expression of relative lowering of vapour pressure -     - wherein    Suppose  Relative lowering of vapour pressure  then,  Option 1) 18.0 Incorrect Option 2) 342 Incorrect Option 3) 160 Incorrect Option 4) 180 Correct
Engineering
99 Views   |

The reaction quotient ($\Theta$ ) for the reaction is given by:

N2(g) + 3 H2(g)$\leftrightarrow$ 2NH3$\Theta = \frac{[NH_{3}]^{2}}{[N_{2}][H_{2}]^{3}}$

The reaction will proceed from right to left if:

• Option 1)

$\Theta =0$

• Option 2)

$\Theta =K_{c}$

• Option 3)

$\Theta < K_{c}$

• Option 4)

$\Theta >K_{c}$

Direction of reaction - Direction of reaction is predicted with the help of reaction quotient Q. - wherein The reaction quotient Q is defined in the same way as equilibrium constant Kc except that concentration are not necessarily equilibrium values.     If Qc > Kc - The reaction will proceed in the direction of reactants ( Reverse direction ) -    Reaction will Proceed from right to...
Engineering
293 Views   |

The PH of boiling water (373k) is ............(Kw at 373K=10-12)

• Option 1)

12

• Option 2)

8

• Option 3)

6

• Option 4)

2

As we learned in concept p(Kw) - Although    may change with temperature the variation in pH with temperature are so small that we often ignore it. - wherein                                                       Option 1) 12 Option is incorrect Option 2) 8 Option is incorrect Option 3) 6 Option is correct Option 4) 2 Option is incorrect
Engineering
92 Views   |

The mole fraction of ethylene glycol (C2H6O2) in an aqueous solution containing 10% of C2H6O2 by mass

• Option 1)

0.932

• Option 2)

0.322

• Option 3)

0.068

• Option 4)

0.0312

As we learned in concept Mole Fraction - -    molar mass of  ethylene glycol (C2H6O2)=62 100g of solution containing 10g of  C2H6O2  and 90g H2O. Mole fraction of  ethylene glycol = = 0.0312   Option 1) 0.932 Option is incorrect Option 2) 0.322 Option is incorrect Option 3) 0.068 Option is incorrect Option 4) 0.0312 Option is correct
Engineering
229 Views   |

The mole fraction of 20% (mass/mass) Kl (aq) is (density of kl(aq)= 1.202gml-1)

• Option 1)

0.0463

• Option 2)

0.05

• Option 3)

0.0263

• Option 4)

0.03

As we learned in concept Mole Fraction - -       20  Mass / mass KI(aq) means 20g of  KI in 100g of solution. 20g of KI in 80g of water   Option 1) 0.0463 Option is incorrect Option 2) 0.05 Option is incorrect Option 3) 0.0263 Option is correct Option 4) 0.03 Option is incorrect
Engineering
120 Views   |

The molality of 2.5 g of ethanoic acid (CH3COOH) in 25g of benzene is

• Option 1)

0.167m

• Option 2)

1.67m

• Option 3)

0.556m

• Option 4)

0.00167m

As we learned in concept Molality - -    moles of ethanoic acid =   Mass of solvent =25g=0.025 kg   Option 1) 0.167m Option is incorrect Option 2) 1.67m Option is correct Option 3) 0.556m Option is incorrect Option 4) 0.00167m Option is incorrect
Engineering
88 Views   |

The molalility of a 15 % (w/v) solution of $H_{2}SO_{4}$ of density of 1.1 $g/cm^{3}$ approx is

• Option 1)

1.2

• Option 2)

1.4

• Option 3)

1.8

• Option 4)

1.6

As we learned in concept Molality - -     = Option 1) 1.2 Option is incorrect Option 2) 1.4 Option is incorrect Option 3) 1.8 Option is incorrect Option 4) 1.6 Option is correct
Engineering
132 Views   |

The formation of these phosgene is represented as , $CO\ + Cl_2\ \leftrightarrow COCl_2$ . The reaction is carried out in 500 ml flask . At equilibrium 0.3 mole of phosgene , 0.1 mole of CO and 0.1 mole of Cl2 are present. The equlibrium constant of the reaction is :

• Option 1)

30

• Option 2)

15

• Option 3)

5

• Option 4)

3

As we learned in concept Law of Chemical equilibrium - At a given temperature, the product of concentration of the reaction products raised to the respective stoichiometric coefficient in the balanced chemical equation divided by the product of concentration of the reactants raised to their individual stoichiometric coefficients has a constant value. - wherein are equilibrium...
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