List of top Chemistry Questions asked in CBSE CLASS XII

The boiling points of the alkyl halides with the same alkyl group decrease in the given order: $RI \gt RBr \gt RCl \gt RF$. Explain the above statement.
Define Racemisation.
On the basis of crystal field theory, write the electronic configuration for $d^5$ ion for which $\Delta_o \lt P$
Write the IUPAC name of the given compound: $CH_3CH(CH_3)CH(Br)CH_3$

Write the major product in the following reaction: [H]
60 g of glucose is dissolved in 250 g of water. Calculate the freezing point of this solution.
(molar mass of glucose = $180~g~mol^{-1}$, $K_f$ for water = $1.86~K~kg~mol^{-1}$)
Calculate emf of the following cell at 298 K:
$Sn | Sn^{2+}(0.001~M) || H^+(0.01~M) | H_{2(g)}(1~bar) | Pt_{(s)}$
Given: $E^\circ_{Sn^{2+}/Sn} = -0.14~V$, $E^\circ_{H^+/H_2} = 0.00~V [\log 10 = 1]$
Rate constant k for the first order reaction is $2.54 \times 10^{-3} s^{-1}$. Calculate the time required for three-fourth of the reactant to decompose. $(\log 4 = 0.60)$
What happens when 2-Bromobutane is made to react with alcoholic potassium hydroxide?
Complete and balance the following equations:
(i) $2Na_2CrO_4 + 2H^+ \longrightarrow$
(ii) $5S^{2-} + 2MnO_4^- + 16H^+ \longrightarrow$
Why second ionization enthalpies of chromium and copper are exceptionally higher than those of their neighbouring elements?
The concentration of the reactant is reduced from 0.6 mol $L^{-1}$ to 0.2 mol $L^{-1}$ in 5 minutes in a first order reaction. Calculate rate constant of the reaction. $(\log 3 = 0.48)$
Write the unit of (i) second order reaction and (ii) zero order reaction.
Indicate the type of isomerism exhibited by the following complex: $[Co(en)_3]Cl_3$
Why transition elements form interstitial compounds?
Define Effective collision.
Assertion (A): Glucose gets oxidized to six carbon gluconic acid on reaction with bromine water.
Reason (R): The carbonyl group is absent in the open chain structure of glucose.
Assertion (A): Aromatic primary amines can be prepared by Gabriel Phthalimide synthesis.
Reason (R): Aryl halides do not undergo nucleophilic substitution with the anion formed by phthalimide.
Assertion (A): Zinc, cadmium and mercury are not considered as transition elements.
Reason (R): These elements have completely filled orbitals in their ground state as well as in their common oxidation states.
Assertion (A): The molecularity of the given reaction is 2
$2HI \longrightarrow H_2 + I_2$
Reason (R): Two molecules of the reactants are involved in simultaneous collision between them.
Define coordination number.
Identify the compound produced by the reduction of Ethanenitrile with Lithium aluminium hydride:
Which of the following molecules is chiral in nature?
Proteins are polymers of $\alpha$-amino acids which are joined to each other by:
Which of the following reactions is not explained by the open chain structure of glucose?