Chemistry Test - 22

Ambidentate ligand are those which can ligate through two or different donor atoms, but during complex formation, only one donor atom is attached to central metal.

(i): \(\mathrm{SCN}^−\) (Ambidentate ligand)

\(\begin{array} {} \ce{\overset{\ominus}{S}-C#\overset{..}{N}}\end{array}\)

\(\mathrm{SCN}^−\) ion has donor atoms \(\mathrm{N}\) and \(\mathrm{S}\). It links to metal as either \(\mathrm{M−SCN}\) or \(\mathrm{M−NCS}\).

(ii): \(\mathrm{NO_3^-}\) (No Ambidentate ligand)

\(\begin{array} {} \ce{O=\overset{\ominus}{\overset{O}{\overset{|}{N}}}=O}\end{array}\)

(iii): \(\mathrm{NO_2^{−}}\)​ (Ambidentate ligand)

\(\begin{array} {} \ce{O=\overset{..}{N}-\overset{\ominus}{O}}\end{array}\)

\(\mathrm{NO_2^{−}}\)​ group has donor atoms \(\mathrm{N}\) and \(\mathrm{O}\). It links to metal as either \(\mathrm{M−ONO}\) or \(\mathrm{M−NO_2}\)​.

(iv): \(\mathrm{C_2O_4^{2-}}\) (No Ambidentate ligand)

A compound is a material formed by chemically bonding two or more chemical elements. A molecule of compound has atoms of different elements. which cannot be separated into its constituent elements by physical methods of separation. The physical properties of a compound are different than its constituent elements. For a given compound the ratio of different elements is fixed.

For the same alkyl group, the boiling point of haloalkanes decreases in the order RI > RBr > RCl > RF. This is due to the increase in van der Waals forces when the size and mass of the halogen atom increases.

The boiling point increases with the increase in the molecular mass of the compound. Hence n-propyl iodide will have maximum boiling point among the given compounds.

Ethanol (\(C _2 H _5 OH\)) dissolves in water.

The formula of ethanol is \(CH _3- CH _2- OH\). Ethanol is an alcohol that is soluble in water. Thisis because of the hydroxyl group \((-O H)\) in the ethanol that is able to form hydrogen bonds withthe water \(\left( H _2 O \right)\) molecules. Hydrogen bonding means dipole-dipole interactions between the two molecules and it can be intramolecular and intermolecular. The intermolecular hydrogen bonding is very high in the ethanol that is why it is soluble.

The second reason is that ethanol is a polar molecular hydrocarbon due to the high electronegativity of the oxygen atom and due to this it is soluble in water.

Saturated hydrocarbons are compounds in which there is a single bond between the carbon atoms. They are also called alkanes and have the general formula C_nH_2n+2

The electronic configuration of nitrogen is 2,5. Nitrogen has only five electrons in the outermost shell. So, it needs three electrons to attain the nearest noble gas configuration. For example, nitrogen atom shares three electrons with another nitrogen atom forming a triple bond. 

Given, \(\left[\mathrm{K}_{\mathrm{sp}}\right]_{\mathrm{Pbl}_2}=8 \times 10^{-9}\)

To calculate solubility of \(\mathrm{PbI}_2\) in \(0.1 \mathrm{M}\) solution of \(\mathrm{Pb}\left(\mathrm{NO}_3\right)_2\).

(I) \(\underset{0 . \overline{\mathrm{im}}}{\mathrm{Pb}\left(\mathrm{NO}_3\right)_2} \rightarrow \underset{0 . \overline{\mathrm{M}}}{\mathrm{Pb}^{2+}(\mathrm{aq})}+\underset{0 . \frac{3}{2} \mathrm{M}}{2 \mathrm{NO}^{-}(\mathrm{aq})}\)

(II) \(\mathrm{Pb}_2(\mathrm{~s}) \rightleftharpoons \mathrm{Pb}^{2+}(\mathrm{aq})+21^{-}(\mathrm{aq})\)

\(\therefore\left[\mathrm{Pb}^{2+}\right]=\mathrm{S}+0.1 \approx 0.1 \)

\(\because \mathrm{S}<<0.1\)

Now, \(\mathrm{K}_{\mathrm{sp}}=8 \times 10^{-9}\)

\({\left[\mathrm{Pb}^2\right]\left[\mathrm{I}^{-}\right]^2=8 \times 10^{-9}} \)

\(0.1 \times(2 \mathrm{~S})^2=8 \times 10^{-9} \)

\(4 \mathrm{~S}^2=8 \times 10^{-8} \Rightarrow \mathrm{S}=141 \times 10^{-6} \mathrm{M}\)

\(\mathrm{x}=141\)

Catenation is the linkage of atoms of the same element into longer chains. Catenation occurs most readily in carbon, which forms covalent bonds with other carbon atoms to form longer chains and structures. This is the reason for the presence of the vast number of organic compounds in nature.

Hydrogen is not a hydrocarbon fuel as it does not contain any carbon atoms in its composition. It is a distinct element and is considered a non-hydrocarbon fuel.

Characteristics of cathode rays are:

• The cathode rays start from the cathode and move towards the anode.
• These rays themselves are not visible but their behaviour can be observed with the help of phosphor materials such as ZnS.
• In the absence of an electrical or magnetic field, these rays travel in straight lines.
• In the presence of an electrical or magnetic field, the behaviour of cathode rays is similar to that expected from negatively charged particles, suggesting that the cathode rays consist of negatively charged particles, called electrons.
• The characteristics of cathode rays (electrons) do not depend upon the material of electrodes and the nature of the gas present in the cathode ray tube.