Chemistry Test - 23

In BCl₃ the valence electrons for boron are 6 (3 of boron and 3 of chlorine), so there are two electrons deficient for the octet configuration. Thus, electron deficient molecule is BCl₃.

Oxidation state represents the degree of oxidation (loss of electrons) of an atom in a chemical compound and Fluorine is the most electronegative element on the periodic table, which means that it is a very strong oxidizing agent and accepts other elements electrons. 

Let be ' \(x\) ' is an oxidation number of oxygen.

Oxidation number of \(F_2\) is -1 .

Net charge is zero because the compound is neutral.

\(2 x-2=0 \)

\( x=\frac{2}{2} =1\)

So the oxidation number of oxygen in \(\mathrm{O}_2 \mathrm{F}_2\) is +1 .

Let, solubility of \(\mathrm{Ca}(\mathrm{OH})_2\) in pure water \(=\mathrm{Smol} / \mathrm{L}\)

\(\mathrm{Ca}(\mathrm{OH})_2 \rightleftharpoons \mathrm{Ca}^{2+}+2 \mathrm{OH}^{-} \)

\(\mathrm{Smol} / \mathrm{L} 2 \times \mathrm{S}(\mathrm{mol} / \mathrm{L}) \)

\(=\left[\mathrm{Ca}^{2+}\right]\left[\mathrm{OH}^{-}\right]^2=\mathrm{S} \times(2 \mathrm{~S})^2=4 \mathrm{~S}^3(\mathrm{~mol} / \mathrm{L})\)

The expression of \(\mathrm{K}_{\mathrm{sp}}\) can also be written as,

\(\mathrm{K}_{s p}=\mathrm{x}^{\mathrm{x}} \cdot \mathrm{y}^{\mathrm{y}} \cdot \mathrm{S}^{\mathrm{x}+\mathrm{y}} \)

\(\quad=1^1 \cdot 2^2 \cdot \mathrm{S}^{1+2} \)

\(\quad=4 \mathrm{~S}^3 \)

\(\mathrm{~K}_{\mathrm{sp}}=\mathrm{x}^{\mathrm{x}} \cdot \mathrm{y}^{\mathrm{y}} \cdot \mathrm{S}^{\mathrm{x}+\mathrm{y}} \)

\(\quad=1^1 \cdot 2^2 \cdot \mathrm{S}^{1+2} \)

\(=4 \mathrm{~S}^3\left[\because \text { For } \mathrm{Ca}(\mathrm{OH})_2: \mathrm{x}=1, \mathrm{y}=2\right]\)

\(\mathrm{x}\) and \(\mathrm{y}\) are the coefficients of cations and anions respectively

\(\mathrm{S}  =\left(\frac{\mathrm{K}_{s p}}{4}\right)^{1 / 3}=\left(\frac{5.5 \times 10^{-6}}{4}\right)^{1 / 3} \)

\( =1.11 \times 10^{-2} \mathrm{~mol} / \mathrm{L}\)

'AB → A + B' is a decomposition reaction.

A decomposition reaction is a type of chemical reaction in which a compound breaks down into two or more substances.

The starting substance is called reactant and the end substances are called products.

Example: Water splits into Hydrogen and Oxygen upon electrical energy.

\({\underset{\text{Water}} {2\mathrm{H}_{2}\mathrm{O}}} \ \ {\overset{\text{Elec.}}\longrightarrow} {\underset{\text{Hydrogen}} {2\mathrm{H}_2}}+ {\underset{\text{Oxygen}}{\mathrm{O}_2}}\)

Transition metals do not show any basic character and from cations complexes in higher oxidation states.

• In the higher oxidation states, the transition metals show acidic nature and form anionic complexes.
• In higher oxidation states metal oxides are more covalent in nature as the polarizing power of the metal ion proportional to its oxidation states. So, their oxides are acidic in nature.

Hyperconjugation is the stabilizing interaction that results from the interaction of the electrons in a C-H σ-bond with an adjacent empty p orbital or a π orbital to give an extended molecular orbital that increases the stability of the system. It is a permanent effect.

Among the given antibiotics, only chloramphenicol i.e., option D contains a nitro group attached to aromatic ring. Its structure is as follows:

If same volume is occupied by the gas, the no. of molecules are same, so no. of moles are same.

1 mole of gas \(\mathrm{N}_2=2 \times 14=28 \mathrm{gm}\)

Taking option (A)

1 mole of \(\mathrm{CO}\) gas \(=12+16=28 \mathrm{gm}\)

So, the gas is \(\mathrm{CO}\).

The given molecule is \(\mathrm{CH}_2 \mathrm{O}\) (formaldehyde).

The oxidation number Oxygen \((\mathrm{O})\) is -2.

Let the oxidation number of carbon \((\mathrm{C})\) is \(x\).

The oxidation number of Carbon \(\mathrm{CH}_2 \mathrm{O}\) is:

\({x}+2(1)+(-2)=0 \)

\({x}+2-2=0 \)

\({x}=0\)

The oxidation number of carbon in \(\mathrm{CH}_2 \mathrm{O}\) is zero.

Density is highest for \(\mathrm{CH}_3 \mathrm{I}\).

Density increases as molecular weight increases. Since, iodide has the highest molecular weight among \(\mathrm{F, Cl, Br}\) and \(\mathrm{I}\), it has the highest density.

Molecular weight of \(\mathrm{F, Cl, Br}\) and \(\mathrm{I}\) are \(\mathrm{18.998403~ u, 35.453~ u, 79.904 ~u}\) and \(\mathrm{126.90447~ u}\) respectively.