




In structure (4), the methylene group (CH2) between two carbonyl groups (C=O) is highly acidic due to the resonance stabilization of the conjugate base. When the hydrogen is removed, the negative charge on the carbon is delocalized between the two carbonyl groups, making the conjugate base more stable. This increased resonance makes the hydrogen highly acidic.
Match List-I with List-II: List-I
The correct increasing order of stability of the complexes based on \( \Delta \) value is:
| List I (Molecule) | List II (Number and types of bond/s between two carbon atoms) | ||
| A. | ethane | I. | one σ-bond and two π-bonds | 
| B. | ethene | II. | two π-bonds | 
| C. | carbon molecule, C2 | III. | one σ-bonds | 
| D. | ethyne | IV. | one σ-bond and one π-bond | 

The molar conductance of an infinitely dilute solution of ammonium chloride was found to be 185 S cm$^{-1}$ mol$^{-1}$ and the ionic conductance of hydroxyl and chloride ions are 170 and 70 S cm$^{-1}$ mol$^{-1}$, respectively. If molar conductance of 0.02 M solution of ammonium hydroxide is 85.5 S cm$^{-1}$ mol$^{-1}$, its degree of dissociation is given by x $\times$ 10$^{-1}$. The value of x is ______. (Nearest integer)
x mg of Mg(OH)$_2$ (molar mass = 58) is required to be dissolved in 1.0 L of water to produce a pH of 10.0 at 298 K. The value of x is ____ mg. (Nearest integer) (Given: Mg(OH)$_2$ is assumed to dissociate completely in H$_2$O)
Sea water, which can be considered as a 6 molar (6 M) solution of NaCl, has a density of 2 g mL$^{-1}$. The concentration of dissolved oxygen (O$_2$) in sea water is 5.8 ppm. Then the concentration of dissolved oxygen (O$_2$) in sea water, in x $\times$ 10$^{-4}$ m. x = _______. (Nearest integer)
Given: Molar mass of NaCl is 58.5 g mol$^{-1}$Molar mass of O$_2$ is 32 g mol$^{-1}$.