The population growth in India is quite alarming. It needs to be stopped immediately. Following can help to curb the population explosion:

1. Spread increasing awareness among people and conduct camps and education seminars for the same. 

2. Increase the age limit for marriage and completely detain child marriages.

3. Increase the incentives to small families and promote contraception and family planing.

4. Remove social stigma associated with sexual health and educate school adolescence about the same.

Methanal ( HCHO ) can be converted into propan-1-ol ( CHCHCHOH ) by following step of reactions -

(i). React methanal ( HCHO ) with ethyl magnesium bromide ( CHCHMgBr ) , CHCHCHOMgBr is formed .

(ii). React CHCHCHOMgBr with water ( HO ) , propan-1-ol  ( CHCHCHOH ) is formed .

• Methanal is also known as formaldehyde .
• Propan-1-ol is a colorless liquid . It's molar mass is 60.09 g / mol .

A non-volatile solute does produce vapour at the boiling point of the solution. They have lower vapour pressure and higher boiling point.

Example: Sugar.

A volatile solute produces vapour at the boiling point of the solution. At the same temperature, they have higher vapour pressure than non-volatile solutes.

Examples: Alcohol, ether, mercury, and gasoline.

Haloarenes can be synthesised by any of the following reactions:

1. By electrophilic substitution reaction:

This involves the direct halogenation of benzene ring in the presence of Lewis acid catalysts like iron or iron (III) chloride.

2. By Sandmeyer’s reaction:

Aniline is treated with sodium nitrite to give a diazonium salt which is then treated with cuprous chloride or cuprous bromide to produce the corresponding aryl halide:

Coagulation is a process of aggregating together the colloidal particles so as to change them into large sized particles which ultimately settle as a precipitate. It can also be called as precipitation.

Coagulation is generally brought about by the addition of electrolyte.

When an electrolyte is added to the colloidal solution, the particles of the sol take up the ion which is oppositely charged and thus get neutralised.

Following are the three methods by which coagulation of lyophobic sols can be carried out.

(i) Electrophoresis: In this process, the colloidal particles move towards oppositely charged electrodes and get discharged resulting in coagulation.

(ii) Mixing of two oppositely charged sols: When equal proportions of oppositely charged sols are mixed, they neutralise each other resulting in coagulation.

(iii) Dialysis: By this method, electrolytes present in sol are removed completely and colloid becomes unstably resulting in coagulation.

Here,no. Of moles of water in 54 g = given weight/molecular weight

=54/18

=3

So, no. Of molecules=avogadro no. ×no. Of moles

=(6.022×10²³)×3

= 18.066 ×10²³ molecules

Aim:

To identify the anionic radicals present in an inorganic mixture of salts by performing various test.

Qualitative analysis involves the detection and identification of acidic and basic radicals present in inorganic salts. Inorganic salts are formed by the reaction of acids and bases or acidic oxides with a base or basic oxides.

Some of the examples of the reaction of acids and bases or acidic oxides with a base or basic oxides are

NaOH + HCl → NaCl + H₂O

CO₂ + 2NaOH → Na₂CO₃ + H₂O

KOH + HNO₃ → KNO₃ + H₂O

2NaOH + H₂SO₄ → Na₂SO₄ + 2H₂O

Continued.........

Click on the link:

<a href="https://ncert.nic.in/pdf/publication/sciencelaboratorymanuals/classXII/chemistry/lelm107.pdf" ping="/url?sa=t&source=web&rct=j&url=https://ncert.nic.in/pdf/publication/sciencelaboratorymanuals/classXII/chemistry/lelm107.pdf&ved=2ahUKEwjU4e_mua7tAhWLzDgGHUbgAi8QFjAQegQIHBAC" rel="noopener" target="_blank">systematic qualitative analysis - ncert</a>

When a slow dry current(stream) of oxygen is passed through silent electrical discharge, oxygen gets converted to ozone(about 10%). The product is known as ozonised oxygen.

 3O₂       →   2O₃    

It is an endothermic process. Use of a silent discharge is important in its preparation to prevent its decomposition

According to the valence bond theory, Electrons in a molecule occupy atomic orbitals rather than molecular orbitals. The atomic orbitals overlap on the bond formation and the larger the overlap the stronger the bond.

The important postulates of the valence bond theory are listed below.

1. Covalent bonds are formed when two valence orbitals (half-filled) belonging to two different atoms overlap on each other. The electron density in the area between the two bonding atoms increases as a result of this overlapping, thereby increasing the stability of the resulting molecule.
2. The presence of many unpaired electrons in the valence shell of an atom enables it to form multiple bonds with other atoms. The paired electrons present in the valence shell do not take participate in the formation of chemical bonds as per the valence bond theory.
3. Covalent chemical bonds are directional and are also parallel to the region corresponding to the atomic orbitals that are overlapping.
4. Sigma bonds and pi bonds differ in the pattern that the atomic orbitals overlap in, i.e. pi bonds are formed from sidewise overlapping whereas the overlapping along the axis containing the nuclei of the two atoms leads to the formation of sigma bonds.

• Nitrogen does not form pentahalides.
• The electronic configuration of nitrogen is 1s²2s²2p³.
• It has 5 valence electrons. In the valence shell, it has s and p orbitals. Nitrogen does not has vacant d orbitals. It cannot expand its octet. In other words, it cannot have more than 8 valence electrons. Hence, nitrogen cannot be pentavalent .

In amines, the hydrogen atoms in ammonia have been replaced one at a time by hydrocarbon groups. On this page, we are only looking at cases where the hydrocarbon groups are simple alkyl groups. The amine functional group contains a basic nitrogen atom with a lone pair of electrons. As such, the group is a derivative of ammonia, in which one or more hydrogen atoms have been replaced by a carbon-containing substituent. Amine groups bonded to an aromatic (conjugated cyclic) structure are known as aromatic amines.

Retention of configuration: A process in which the relative configuration of an atom is retained. If the atom in question is a stereocenter, retention of configurationusually (but not always) changes R absolute configuration into R, and S into S.

Inversion of configuration: A process in which the relative configuration of an atom is changed. If the atom in question is a stereocenter, inversion of configuration usually (but not always) changes R absolute configurationinto S, and S into R.
Racemization refers to the converting of an enantiomerically pure mixture (one where only one enantiomer is present) into a mixture where more than one of the enantiomers are present. If the racemization results in a mixture where the enantiomers are present in equal quantities