How do you convert the following:
(i) C6H5CONH2 to C6H5NH2
(ii) Aniline to phenol
(iii) Ethanenitrile to ethanamine
Write the chemical equations involved when aniline is treated with the following reagents:
(i) Br2 water
(ii) CHCI3 + KOH
(iii) HCl
Write the names and structures of the monomers of the following polymers:
(i) Buna-S
(ii) Glyptal
(iii) Polyvinyl chloride
(i) Write the product obtained when D-glucose reacts with H2N - OH.
(ii) Amino acids show amphoteric behaviour. Why?
(iii) Why cannot vitamin C be stored in our body?
Give reasons for the following:
(i) Phenol is more acidic than ethanol.
(ii) The boiling point of ethanol is higher in comparison to methoxymethane.
(iii) (CH3)3C - O - CH3 on reaction with HI gives CH3OH and (CH3)3C -I as the main products and not (CH3)3C -OH and CH3I.
Seeing the growing cases of diabetes and depression among young children, Mr Lugani, the principal of on reputed school organised a seminar in which he invited parents and principals. They all resolved this issue by strictly banning junk food in schools and introducing healthy snacks and drinks like soup, lassi, milk, etc. in school canteens. They also decided to make compulsory half an hour of daily physical activities for the students in the morning assembly. After six months, Mr Lugani conducted the health survey is most of the schools and discovered a tremendous improvement in the health of the students.
After reading the above passage, answer the following questions:
(i) What are the values (at least two) displayed by Mr Lugani?
(ii) As a student, how can you spread awareness about this issue?
(iii) What are antidepressant drugs? Give an example.
(iv) Name the sweetening agent used in the preparation of sweets for a diabetic patient.
(a) Account for the following:
(i) Zr and Hf have almost similar atomic radii.
(ii) Transition metals show variable oxidation states.
(iii) Cu+ ion is unstable in aqueous solution.
(b) Complete the following equations:
(i) 2 MnO2 + 4 KOH + O2--->
(ii) 2 Na2CrO4 + 2 H + -->
|
Cr |
Mn |
Fe |
Co |
Ni |
Cu |
-0.91 |
-1.18 |
-0.44 |
-0.28 |
-0.25 |
-0.34 |
From the given data of E0 values answer the following Question:
(i) Which is strongest why is value exceptionally positive?
(ii) Why is value highly negative as compared to other elements?
(iii) Reducing agent Cr2+ or Fe2+? Give reason
(b) Why do actinoids show wide range f oxidation states? Write on the similarity between the chemistry of lanthanoids and actinoids.
The E0 (M2+/M) value of a metal depends on the energy changes involved in the formation of the M2+ ion:
1. Sublimation: The energy required for converting one mole of an atom from the solid state to the gaseous state
M(s) ---> M (g) sH (Sublimation energy)
2. Ionisation: The energy required to take out electrons from one mole of atoms in the gaseous state to form the corresponding cation in the gaseous state
M (g) --->M2+ (g) iH (Ionization energy)
3. Hydration: The energy released when one mole of ions are hydrated
M (g)---> M2+ (aq) hydH (Hydration energy)
Now, copper has high energy of atomization and low hydration energy. Hence, theE0(Cu2+/Cu) is exceptionally positive.
(ii) The value is highly negative as compared to other elements because of the extra stability of Mn2+ due half -filled d orbitals.
(iii) The following reactions are involved when Cr2+ and Fe+ act as reducing agent:
Cr2+ ---> Cr3+ + e-
Fe2+ ----> Fe3+ + e-
The value is -0.41 V and is + 0.77V. This means that Cr2+ can be easily oxidised to Cr3+ but Fe2+ does not get oxidised to Fe3+ easily, therefore, Cr2+ is a stronger reducing agent than Fe3+.
(b) In actinoids, the 5f, 6d, 7s shells are present. These three shells are of comparable energies; therefore electrons can remove from these shells. This gives rise f variable oxidation states in actinoids.
Following are the similarities between actinoids and lanthanoids:
(i) The size of atom: It decreases across the series in both actinoids (due to actinoid contraction) and lanthanoids(due to lanthanoids contraction).
(ii) Oxidation states: Lanthanoids and actinoids generally show +3 oxidation states. However, some element in the actinoids series is capable of exhibiting oxidation states higher than +3.
A compound 'A' of molecular formula C2H3OCl undergoes a series of reactions as shown below. Write the structures of A, B, C and D in the following reactions:
(b) Distinguish between the following:
(i) C6H5-COCH3 and C6H5 - CHO
(ii) Benzoic acid and methyl benzoate
(c) Write the structure of 2- methylbutanal.