Science (English Medium) कक्षा १२ - CBSE Question Bank Solutions

Complete the following equation:

\[\ce{2MnO4- + 6H+ + 5NO2- ->}\]

Illustrate the following reaction giving suitable example in each case:Gabriel phthalimide synthesis

A first order reaction takes 23.1 minutes for 50% completion. Calculate the time required for 75% completion of this reaction.

(log 2 = 0.301, log 3 = 0.4771, log 4 = 0.6021)

When chromite ore FeCr₂O₄ is fused with NaOH in presence of air, a yellow-coloured compound (A) is obtained, which on acidification with dilute sulphuric acid gives a compound (B). Compound (B) on reaction with KCl forms an orange coloured crystalline compound (C).

(i) Write the formulae of the compounds (A), (B) and C.

(ii) Write one use of compound (C).

Complete the following chemical equation

8MnO₄^- + 3S₂O₃^2- + H₂O →

Write the main product(s) in each of the following reactions:

Write the formula for the following complex:

Pentaamminenitrito-O-Cobalt(III)

Name the reagents used in the following reactions:

Complete the following equation :

`2MnO_4^(-)+6H^++5NO_2^(-)rarr`

How do you convert the following : Propan-2-ol to 2-methylpropan-2-ol

An aromatic compound 'A' of molecular formula C₇H₇ON undergoes a series of reactions as shown below. Write the structures of A, B, C, D and E in the following reactions :

A first order reaction takes 30 minutes for 50% completion. Calculate the time required for 90% completion of this reaction.

(log 2 = 0.3010)

How much charge is required for the reduction of 1 mol of Zn²⁺ to Zn?

Using IUPAC norms write the formulate for the following coordination compound: 

Hexaamminecobalt(III) chloride

Using IUPAC norms write the formulate for the following coordination compound:

Potassium tetrachloridonickelate (II)

How do you convert the following: C₆H₅CONH₂ to C₆H₅NH₂

How do you convert the following: Ethanenitrile to ethanamine

Complete the following equations : 2 MnO₂ + 4 KOH + O₂ →

Complete the following equations : 2 Na₂CrO₄ + 2 H ⁺ →​

Write the structures of the main products when acetone (CH₃ − CO − CH₃) reacts with the following reagents :

CH₃MgBr and then H₃O⁺