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

Write the structure of the compound whose IUPAC name is as follows:

Cyclohexylmethanol

Write the structure of the compound whose IUPAC name is as follows:

3-Cyclohexylpentan-3-ol

Write the structure of the compound whose IUPAC name is as follows:

Cyclopent-3-en-1-ol

Which one of the following has the highest dipole moment?

What is the covalence of nitrogen in N₂O₅?

Bond angle in `PH_(4)^(+)` is higher than that in PH₃. Why?

Why does the reactivity of nitrogen differ from phosphorus?

How is nitrogen prepared in the laboratory? Write the chemical equations of the reactions involved.

Give the resonating structure of N₂O₅.

Write one similarity between Physisorption and Chemisorption

Give reasons  Although –NH₂ is o/p directing group, yet aniline on nitration gives a significant amount of m-nitroaniline

Do the following conversions in not more than two steps :

Ethyl benzene to Benzoic acid

Do the following conversions in not more than two steps :

Propanone to Propene

Following data are obtained for reaction :

N₂O₅ → 2NO₂ + 1/2O₂

1) Show that it follows first order reaction.

2) Calculate the half-life.

(Given log 2 = 0.3010, log 4 = 0.6021)

A 10% solution (by mass) of sucrose in water has freezing point of 269.15 K. Calculate the freezing point of 10% glucose in water, if freezing point of pure water is 273.15 K

Given : (Molar mass of sucrose = 342 g mol⁻¹)

(Molar mass of glucose = 180 g mol⁻¹)

Account for the following:

E° value for the Mn³⁺/Mn²⁺ couple is highly positive (+1.57 V) as compare to Cr³⁺/Cr²⁺.

Write the structure of 2,4-dinitrochlorobenzene

Write the formula of an oxo-anion of Chromium (Cr) in which it shows the oxidation state equal to its group number

A first order reaction takes 20 minutes for 25% decomposition. Calculate the time when 75% of the reaction will be completed.

(Given : log = 2 = 0·3010, log 3 = 0·4771, log 4 = 0·6021)