Describe the manufacture of sulphuric acid by contact process with labelled diagram. Give equation of related reactions also.

Sulphuric acid is manufactured by the contact process. The process involves the following steps : (i) SO 2 is prepared by burning sulphur or iron pyrites in excess of air. S ( s ) + O 2 ( g ) → SO 2 ( g ) (ii) SO 2 is oxidized to SO 3 with atmospheric oxygen in the presence of a catalyst ( V 2 O 5 ) . This reaction is reversible as well as exothermic in nature and the key reaction for the process. 2 SO 2 ( g ) + O 2 ( g ) ⇌ V 2 O 5 2 SO 3 ∆ H = - 196 . 6 kJ mol - 1 (iii) SO 3 is absorbed in about 98 % H 2 SO 4 to form oleum ( H 2 S 2 O 7 ) or fuming sulphuric acid. SO 3 + H 2 SO 4 → H 2 S 2 O 7 (iv) Dilution of oleum with water gives H 2 SO 4 of the desired concentration. The sulphuric acid obtained by contact process in 96 - 98 % pure. H 2 S 2 O 7 + H 2 O → 2 H 2 SO 4

How is SO 2 an air pollutant? Clarify.

Sulphur dioxide is an air pollutant emitted primarily from fossil fuel combustion. On dissolution in rain water, SO 2 produces acid rain as follows: 2 SO 2 + O 2 + 2 H 2 O → 2 H 2 SO 4 Hence, we can say that it is an air pollutant.

Give the name and formula of two Oxoacids of Phosphorous.

The two oxoacids of phosphorus are pyrophosphoric acid having molecular formula H 4 P 2 O 7 and hypophosphorous acid having molecular formula H 3 PO 2 .

How is ammonia manufactured industrially? Describe with diagram.

Haber's process is used for manufacturing ammonia ( NH 3 ). N 2 ( g ) + 3 H 2 ( g ) ⇌ 2 NH 3 ( g ) Δ f H o = − 46 . 1 kJ / mol Optimum conditions (to obtain maximum yield of ammonia) are around 200 atm pressure, 700 K temperature and a catalyst containing iron oxide with small amounts of K 2 O and Al 2 O 3 . The reaction is reversible exothermic reaction and optimum conditions mentioned above are in accordance with Le Chatelier's principle.

Describe with diagram the Laboratory method for the preparation of Ozone.

Ozone is prepared in the laboratory by ozonisers like Seimen's ozoniser. The description of Seimen's ozoniser is given below: Seimen's ozoniser consists of two co-axial glass tubes sealed at one end. The inner surface of the inner tube and the outer surface of the outer tube are covered with tin foils. The inner and outer coatings of tin foil are connected to the terminals of an induction coil. One end of the coaxial tubes has an inlet for pure and dry dioxygen and the other end has an outlet for the ozonised oxygen. A slow stream of pure, dry and cold dioxygen is passed through the annular space between the concentric tubes and subjected to the silent electric discharge when some dioxygen gets converted into ozone. 3 O 2 ( g ) ⇌ silent electric discharge 2 O 3 ( g )

Describe with labelled diagram the Lead Chamber process for the manufacture of sulphuric acid.

We should know that classic lead chamber process consist of 3 stages: Glover tower, lead chambers and Gay-Lussac Tower. The gases issuing from the chambers consist mainly of nitrogen dioxide, nitric oxide and atmospheric nitrogen. The two former are dissolved by the sulphuric acid in the Gay-Lussac tower with formation of a solution of nitrosylsuphuric acid in excess of sulphuric acid: NO + NO 2 + 2 H 2 SO 4 → 2 NO 2 . SO 2 . OH Nitrosylsulphuric acid + H 2 O As the formation of nitrosylsulphuric acid is a reversible process, dilution of the sulphuric acid solution in the Glover tower tends to cause hydrolysis, which is aided by the high temperature; the oxides of nitrogen resulting from the decomposition pass on with the sulphur dioxide and excess of air to the chambers, whilst the sulphuric acid descends and issues at the bottom of the tower. In addition to the forgoing process, it should be noted that the Glover tower actually produces sulphuric acid. This is brought about by interaction of the sulphur dioxide in the burner gases with nitrosylsulphuric acid, as follows: 2 NO 2 . SO 2 . OH Nitrosylsulphuric acid + SO 2 + 2 H 2 O → 3 H 2 SO 4 Sulphuric acid + 2 NO

Explain the trend in property in halogen family as given under Electron Affinity

Electron affinity of the halogens become less negative down the group. However, the negative electron gain enthalpy of fluorine is less than that of chlorine due to small size of fluorine atom. As a result, there are strong inter electronic repulsions in the relatively small 2 p orbitals of fluorine and thus, the incoming electron does not experience much attraction. Therefore, the correct order of electron affinity is Cl > F > Br > I .

Explain the trend in property in halogen family as given under Oxidation States

All the halogens exhibit - 1 oxidation state. However, chlorine, bromine and iodine exhibit + 1 , + 3 , + 5 and + 7 oxidation states also. The higher oxidation states of chlorine, bromine and iodine are realised mainly when the halogens are in combination with the small and highly electronegative fluorine and oxygen atoms.

E M B I B E

EMBIBE CHAPTER WISE PREVIOUS YEAR PAPERS FOR CHEMISTRY>Chapter -1 - The p-Block Elements>Uttarakhand Board-2018>Q 2

EASY

12th Uttarakhand Board

IMPORTANT

Earn 100

Why does $O_{3}$ acts as a powerful oxidising agent?

Chapter-Wise 3D Chemistry Videos from Embibe Experts EMBIBE CHAPTER WISE PREVIOUS YEAR PAPERS FOR CHEMISTRY

07 min 44 sec

Anomalous Properties of Fluorine

Anomalous properties of fluorine may be attributed due to its very small size, high electronegativity and absence of vacant d-orbitals in the valence shell....

06 min 22 sec

Properties of Group 17 Elements

The Group 17 elements are known to be highly reactive elements. They form halides with most of the metals and non-metals. Let’s explore a few of these proper...

04 min 09 sec

Hydrogen Halides

Hydrogen halides are usually acidic, but do you know which among them is the most stable acid? Let's see the relation between the stability and acidic nature...