Chemistry Test - 7

Elements of group \(13\) are part of p-block elements.

The last electron enters in the outermost p-orbital in the p block elements, from group \(13\) to group \(18\) the entire elements belong to p-block, whereas group \(13\) is called a boron family. It includes the elements boron, aluminum, gallium, indium and thallium.

An ion exchange resin containing \(\mathrm{R}-\mathrm{COOH}\) group exchange cations like \(\mathrm{Ca}^{2+}\), \(\mathrm{Mg}^{2+}\), \(\mathrm{Na}\), \(\mathrm{Fe}^{2+}\) with \(\mathrm{H^+}\) when hard water is passed through it. This resin is called cation exchange resin.

Let us consider the formation of \(\mathrm{SO}_{3}\) in the following reversible reaction:

\(2 \mathrm{SO}_{2}(\mathrm{~g})+\mathrm{O}_{2}(\mathrm{~g}) \leftrightharpoons 2 \mathrm{SO}_{3}(\mathrm{~g})\)

In the graph (1), \(A, B\) and \(C\) are \(\mathrm{SO}_{3}, \mathrm{SO}_{2}\) and \(\mathrm{O}_{2}\) respectively.

\(A\) represents \(\mathrm{SO}_{3}\) as the concentration of product increases with time.

\(B\) and \(\mathrm{C}\) represents \(\mathrm{SO}_{2}\) and \(\mathrm{O}_{2}\) respectively as the concentration of reactants decreases with time.

The product formed in the reaction is (\(1\)-chloropropyl)-benzene

\({C}_{6} {H}_{5} {CH}_{2} {CH}={CH}_{2} \stackrel{H C l}{\longrightarrow} {C}_{9} {H}_{11} {Cl}\)

The molar mass of oxygen is \(16\) grams.

\(1\) mole oxygen weighs \(16\) grams.

\(64\) gram oxygen \(=\frac{64}{16}=4\) mole oxygen .

\(1\) mole of any element contains \(6.022 \times 10^{23}\) atoms.

\(\therefore\) No. of atoms in \(4\) moles \(\mathrm{O}_{2}=4 \times 6.022 \times 10^{23}=24.088 \times 10^{23}\) atoms.

So, the number of Oxygen atoms in \(64\) grams of Oxygen gas is \(24.088 \times 10^{23} \approx 24.092 \times 10^{23}\).

Equation of reaction: \(2 ~A+B \leftrightarrow A_{2} B\)

The concentration of \(A\) is doubled

The concentration of \(B\) is halved

We know that the expression for the rate of reaction is given by

\(R=K[A]^{2}[B] \ldots . .\) \((i)\)

where \(K\) is the equilibrium constant

Now, we have

New \([A]=[2 × A] \ldots\) \((ii)\)

New \([B]\) \(=\frac{1}{2}×B] \ldots \ldots\) \((iii)\)

Therefore,

New \(R=K ×\) New \([A]^{2}\)\(×\) New \([B]\)

Substituting the values from \((i)\) \(\&\) \((ii)\), we get

New \(R\)

\(=K\left[2 × A\right]^{2}[\frac{1}{2} ×B]\)

\(=K × 4 × [A]^{2} × \frac{1}{2} × [B]\)

\(=2 × K[A]^{2}[B] \ldots \ldots\) \((iv)\)

Then, from equation \((i)\) \(\&\) \((iv)\) we can conclude that, after the concentration of \(A\) is doubled and \(B\) is halved the rate of reaction increases by \(2\) times.

As we know that the indicators are compounds that are added to the analyte solutions in which titrant is added. Titration is the quantitative analysis of any sample. The titration can be acid base type usually, but it can also be redox or other type. An indicator is used in the process of titration. This is added in the analyte, which is added in the conical flask, and to this the titrant from the burette is added. Indicator is the substance that changes or imparts certain color at the stoichiometric end point of the titration. This means when a certain concentration of the acid or a base is completely neutralized, then at the end point we observe a color change.

For example, an indicator \((H I n)\) can dissociate in the following way.

\(H I n \rightleftharpoons H^{+}+I{n}^{-}\) thus, \(E_{\text {EquilibriumConstant }}\)

\(K_{I n}=\frac{\left[H^{+}\right]\left[{In}^{-}\right]}{\left[H_{I n}\right]}\)

On further solving we get;

\(p K_{I n}=p H-\log \frac{\left[In^{-}\right]}{[H I n]}\)

\(\log \frac{\left[In^{-}\right]}{[H I n]}=p H-p K_{I n}\)

Acidic hydration of 2-phenyl propene follows an electrophilic reaction mechanism forming an intermediate 3° carbocation (more stable), thereby forming 2-phenyl-2-propanol.

The pollutants which come directly into the air from sources are called primary pollutants. Primary pollutants are sometimes converted into secondary pollutants.NO belongs to secondary air pollutants.NO (nitrogen oxide) which reacts with oxygen to form nitrogen dioxide, participate in a complex of ultraviolet-driven photochemical reactions. and it also forms acid rain when it reacts with water.

For a compound with n chirality centers there is the possibility of a maximum of 2n stereoisomers. Each chirality center can have either an S or R configuration.

\(3\)-Bromo-\(2\)-butanol has 2 chirality centers with different sets of 4 substituents. In this case there 2 chirality.

So number of stereoisomers are 2 × 2 = 4

\(\therefore\) Total number of stereoisomers are 4.