Science (English Medium) इयत्ता १२ - CBSE Question Bank Solutions for Chemistry

\[\ce{Phenol ->[Zn, dust] 'X' ->[CH3Cl][Anhy. AlCl3] 'Y' ->[Alkaline][KMnO4] 'Z'}\]

The product ‘Z’ is:

Among the following sets of reactants which one produces anisole?

IUPAC name of the compound is:

\[\begin{array}{cc}
\ce{CH3-CH-OCH3}\\
|\phantom{....}\\
\ce{CH3}\phantom{..}
\end{array}\]

The correct acidic strength order of the following is:

     (I)

    (II)

     (III)

Which of the following is a correct statement for C₂H₅Br?

Given below are two statements labelled as Assertion (A) and Reason (R).

Assertion (A): Molarity of a solution changes with temperature.

Reason (R): Molarity is a colligative property.

Select the most appropriate answer from the options given below:

Which of the following is not true about the ionic solids?

An excess of potassium ions makes KCl crystals appear violet or lilac in colour since:

(i) some of the anionic sites are occupied by an unpaired electron.

(ii) some of the anionic sites are occupied by a pair of electrons.

(iii) there are vacancies at some anionic sites.

(iv) F-centres are created which impart colour to the crystals.

Which of the following cannot be regarded as molecular solid?

(i) SiC (Silicon carbide)

(ii) AlN

(iii) Diamond

(iv) I₂ 

Why are liquids and gases categorised as fluids?

Inspite of long range order in the arrangement of particles why are the crystals usually not perfect?

Match the terms given in Column I with expressions given in Column II.

Define the following modes of expressing the concentration of a solution. Which of these modes are independent of temperature and why?

w/w (mass percentage)

Define the following modes of expressing the concentration of a solution. Which of these modes are independent of temperature and why?

V/V (volume percentage)

Define the following modes of expressing the concentration of a solution. Which of these modes are independent of temperature and why?

(iii) w/V (mass by volume percentage)

Define the following modes of expressing the concentration of a solution. Which of these modes are independent of temperature and why?

ppm. (parts per million)

Define the following modes of expressing the concentration of a solution. Which of these modes are independent of temperature and why?

x (mole fraction)

Define the following modes of expressing the concentration of a solution. Which of these modes are independent of temperature and why?

M (Molarity)

Define the following modes of expressing the concentration of a solution. Which of these modes are independent of temperature and why?

m (Molality)

Consider a first order gas phase decomposition reaction given below :
\[\ce{A(g) -> B(g) + C(g)}\]
The initial pressure of the system before decomposition of A was p_i. After lapse of time ‘t’, total pressure of the system increased by x units and became ‘p_t’ The rate constant k for the reaction is given as ______.