MCQ
Identify the incorrect statement
  • A
    An octa deca peptide contains $18$ amino acid residues and $17$ peptide bonds
  • B
    Addition of an inert gas into a system in thermodynamic equilibrium for the dissociation of $PC{l_5}$ shifts the equilibrium to the left.
  • When gold dissolves in aquaregia the complex formed is chloroauric acid
  • D
    If the $pH$ value of a solution is to be decreased from $5$ to $34$, the hydrogen ion concentration must be increased twice the initial value.

Answer

Correct option: C.
When gold dissolves in aquaregia the complex formed is chloroauric acid
c
Change in $pH$ is $\Delta pH = pH _2- pH _1=5-3=2$.

Thus ratio of hydrogen ion concentration is $\frac{[ H ] 2^{+}}{[ H ] 1^{+}}=10^2=100$.

Hence, the hydrogen ion concentration should be increased by $100$ times.

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