Chemistry Test - 31

Functional group -CHO is present in Aldehydes. Aldehyde is a class of organic compounds, in which a carbon atom shares a double bond with an oxygen atom, a single bond with a hydrogen atom, and a single bond with another atom or group of atoms (designated R in general chemical formulas and structure diagrams).

The double bond between carbon and oxygen is characteristic of all aldehydes and is known as the carbonyl group. Aldehydes are often written in the short form of R–CHO

Aldehydes contain the carbonyl group bonded to at least one hydrogen atom. The IUPAC system of nomenclature assigns a characteristic suffix -al to aldehydes. For example, H₂C=O is methanol.

• The functional group of -OH is Alcohol.
• The functional group of >C=O is Ketone.
• The functional group of -COOH is Carboxylic acid.

All the alkali metals are good reducing agents due to their low ionization energies. The reducing character of group 1 elements follows the increasing order of Sodium, Potassium, rubidium, Caesium and lithium.

Given that:

Concentration of \({Na}_{2} {CO}_{3}=1.0 \times 10^{-4} {M}\)

\(\therefore\left[{CO}_{3}^{-}\right]=1.0 \times 10^{-4} {M}\)

i.e., \(s=1.0 \times 10^{-4} {M}\)

At equilibrium:

\(\left[{Ba}^{++}\right]\left[{CO}_{3}^{--}\right]={K}_{{sp}}\) of \({BaCO}_{3}\)

\(\left[{Ba}^{++}\right]=\frac{K_{s p}}{\left[{CO}_{3}^{--}\right]}\)

\(=\frac{5.1 \times 10^{-9}}{1.0 \times 10^{-4}}\)

\(=5.1 \times 10^{-5} {M}\)

Neon is a chemical element with the symbol Ne and atomic number 10. It is a noble gas. Neon is a colourless, odourless, inert monatomic gas under standard conditions, with about two-thirds the density of air. It was discovered (along with krypton and xenon) in 1898 as one of the three residual rare inert elements remaining in dry air after nitrogen, oxygen, argon and carbon dioxide were removed.

The surface tension of a liquid decreases with increase in temperature.

The strength of surface tension depends on intermolecular forces. As temperature increases, molecules of liquid become more active and they move more rapidly; therefore, the intermolecular forces are more instable. Surface tension decreases with increasing temperature.

At equilibrium, Gibbs free energy change \(\left(\Delta \mathrm{G}^{\circ}\right)\) is equal to zero. The following thermodynamic relation is used to show the relation of \((\Delta \mathrm{G}^{\circ})\) with the enthalpy change \(\left(\Delta \mathrm{H}^{\circ}\right)\) and entropy change \(\left(\Delta \mathrm{S}^{\circ}\right)\).

\(\Delta \mathrm{G}^{\circ}=\Delta \mathrm{H}^{o}-\Delta \mathrm{S}^{o}\)

\(0=30 \times 10^{3}\left(\mathrm{~J} \mathrm{~mol}^{-1}\right)-\mathrm{T} \times 105\left(\mathrm{~J} \mathrm{~K}^{-1}\right) \mathrm{mol}^{-1}\)

Therefore,

\(T=\frac{30 \times 10^{3}}{105} \mathrm{~K}=285.71\mathrm{~K}\)

In nitroprusside ion, the iron and NO exist as Fe(II) and \(NO^{+}\) rather than Fe(III) and NO. These forms can be distinguished by measuring the solid-state magnetic moment.

Nitroprusside ion is \(\left[\mathrm{Fe}(\mathrm{CN})_{5} \mathrm{NO}\right]^{2-}\). If the central atom iron is present here in \(\mathrm{Fe}^{2+}\) form, its effective atomic number will be \(26-2+(6 \times 2)=36\) and the distribution of electrons in valence orbitals (hybridised and unhybridized) of the \(\mathrm{Fe}^{2+}\) will be

It has no unpaired electron. So this anionic complex is diamagnetic. If the nitroprusside ion has \(\mathrm{Fe}^{3+}\) and \(\mathrm{NO}\), the electronic distribution will be such that it will have one unpaired electron i.e. the complex will be paramagnetic.

Thus, magnetic moment measurement establishes that in nitroprusside ion, the Fe and NO exist as F(II) and \(NO^{+}\) rather than Fe(III) and NO.

Given: Weight of Urea \(=12 {~g}\)

And, weight of sucrose \(=68.4 {~g}\)

We know that: Number of moles \(=\frac{\text{Weight}}{\text{Molar mass}}\)

Therefore, Moles of urea \(=\frac{12}{60}=0.2\)

(Molar mass of Urea is \(60 {gm}\). )

Moles of sucrose \(=\frac{68.4}{342}=0.2\)

(Molar mass of sucrose is \(342 {gm}\))

Since, there are equal moles of solute in equal volumes of water, the mole fraction is the same. As per Raoult's law, the relative lowering of pressure will also be the same.

Sustainable development focuses on more use of renewable resources.

Renewable resources are the resources which can be replenishment. Like sunlight, rainwater. The use of renewable resources favours the sustainable development. As sustainable development focuses on the meeting the need of present without hampering the future generation.

All the mentioned compounds are examples of molecular solids:

• \(I_{2}\) is an example of non polar molecular solid,
• Solid \(\mathrm{NH}_{3}\) is an example of polar molecular solid and
• Ice is an example of hydrogen bonded molecular solid.