Equilibrium

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Ans: As, NH₃ is Lewis base while BF₃  is Lewis acid. Lewis electronic theory of acids and bases explains it. Hybridisation state: N in NH₃ is sp³ hybridised and Boron in BF₃ is sp² hybridised.

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Ans:

K_sp=3.2 × 10^-8

PbCl₂? Pb₂⁺ +2Cl^-

K_sp= (S) (2S)²

K_sp=4S³

s³=43.2 × 10^-8

s³=8 × 10^-9

s=2 × 10^-3

Molar   mass   of   PbCl₂=278g/mol   

By

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Ans: Let us assume S be the solubility of Al (OH)³.

K_sp= [Al³⁺] [OH^-]3= (S) (3S)³=27S⁴

S⁴=27K_sp=27 × 10²⁷ × 10^-11=1 × 10^-12

S=1×10⁻³ mol L^-1.

(i) Solubility of Al (OH)³ ? : Molar

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Ans: we can find the pH of the solution as-

pH of solution A=6

Hence, concentration of  ^[H⁺] ion in solution A=10-6mol L^-1

pH of solution B=4

Therefore, concentration of  [H]⁺ ion in solution&nbs

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Ans: pH of HOCL = 2.85

But, - pH = log [H⁺]

 -2.85=log [H⁺]

= -3.15 = log [H⁺]

  [H⁺]=anti log3.15

  [H⁺]= 1.413* 10^-3 

or weak mono basic acid

[H⁺]= $\sqrt[]{K_a*}$  C

= $K_a$  = $\frac{{\left. [{\mathrm{H}}^{+}\right]}^2}{\mathrm{C}}$  = $\frac{{\left(\mathrm{}1.43*{10}^{-3}\right)}^2\mathrm{ }\mathrm{ }}{0.08}$

=24.957 $*\mathrm{}$ 10^-6

=2.4957 $*\mathrm{}$ 10^-5

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Ans: The chemical equation is given below-  

                             &nb

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Ans: Given with the pH = 5 as, pH= - log  [ H⁺ ] 

  [ H⁺ ] =10^-5M

On 100 times dilution-

  [ H⁺ ] =10^-7M.

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Ans: Here concentration of water cannot be neglected since the solution is very dilute. pH will be less than 7.0. Hence, the total concentration is given as -

  [ H₃O⁺ ] =10^-8+10^-7M.

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Ans: At a given time the reaction quotient Q for the reaction will be given by the expression:

Q= $\frac{\left[\mathbf{H}2\right]\left[\mathbf{I}2\right]}{\left[\mathbf{H}\mathbf{I}\right]\mathrm{}}$  = $\frac{[1\times 10??\times 1\times 10??]}{{\left(2\times \mathrm{}10^{-5}\right)}^2}$  = $\frac{1}{2}\mathrm{}$ = 0.25

 = 2.5×10⁻¹

As the value of the reaction quotient is greater than the value of K_c i.e. 

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Ans: Correct order of pH is -

NH₄Cl  C₆H₅COONH₄  KNO₃  CH₃COONa

Salts of strong acid and strong base do not hydrolyse and form neutral solution thus, pH will be nearly 7 of KNO₃?  

In sodium acetate,