List of top Questions asked in CBSE CLASS XII

Br$_2$/CS$_2$

Conc. HNO$_3$

Why phenol does not undergo protonation readily?

Which is a stronger acid – phenol or cresol? Give reason.

Write the IUPAC name of the product formed in the Reimer-Tiemann reaction.

Write the cell reaction and calculate the e.m.f. of the following cell at 298 K: \[ \text{Sn}(s) \mid \text{Sn}^{2+} (\text{0.004 M}) \parallel \text{H}^+ (\text{0.02 M}) \mid \text{H}_2 (\text{1 Bar}) \mid \text{Pt}(s) \] (Given: $ E^\circ_{\text{Sn}^{2+}/\text{Sn}} = -0.14 \, \text{V}, E^\circ_{\text{H}^+/\text{H}_2} = 0.00 \, \text{V} $)

On the basis of $ E^\circ $ values, O$_2$ gas should be liberated at the anode, but it is Cl$_2$ gas that is liberated in the electrolysis of aqueous NaCl.

Conductivity of CH$_3$COOH decreases on dilution.

Write the anode and cathode reactions and the overall cell reaction occurring in a lead storage battery during its use.

Calculate the potential for half-cell containing 0.01 M K$_2$Cr$_2$O$_7$(aq), 0.01 M Cr$^{3+}$(aq), and 1.0 x 10$^{-4}$ M H$^+$(aq).

Alkyl halides undergoing nucleophilic bimolecular substitution reaction involve:

Arrange the following compounds in increasing order of their boiling points:

The correct IUPAC name of [Pt(NH$_3$)$_2$Cl$_2$]$^{2+} $ is:

Low spin tetrahedral complexes are not known.

Acidified KMnO$_4$ oxidizes sulphite to:

The magnetic moment is associated with its spin angular momentum and orbital angular momentum. Spin only magnetic moment value of Cr$^{3+}$ ion (Atomic no. : Cr = 24) is:

What type of isomerism is shown by the complex $[\text{Co(NH}_3)_6][\text{Cr(CN)}_6]$?

Standard electrode potential for Sn$^{4+}$/Sn$^{2+}$ couple is +0.15 V and that for the Cr$^{3+}$/Cr couple is -0.74 V. The two couples in their standard states are connected to make a cell. The cell potential will be:

Why is a solution of $\text{Ni(H}_2\text{O})_6^{2+}$ green while a solution of $\text{Ni(CN)}_4^{2-}$ is colourless? (At. No. of Ni = 28)

Which of the following can be both a symmetric and skew-symmetric matrix?

In 'Common size income statement' each item is expressed as a percentage of ____

_____ is not a tool of 'Analysis of Financial Statements'.

The Quick Ratio of a company is 1 : 1. Which of the following transactions will result in increase in Quick Ratio?

Pass the necessary journal entries for forfeiture and reissue of shares in the following cases:
(i) Premier Ltd. forfeited 600 shares of Rs 10 each issued at a premium of Rs 3 per share (payable with allotment) for non-payment of allotment money of Rs 7 per share including premium. The first and final call of Rs 3 per share was not yet made. The forfeited shares were reissued at Rs 13 per share fully paid up.
(ii) Risha Ltd. forfeited 1000 shares of Rs 10 each, Rs 8 per share called up issued at a premium of Rs 2 per share to Atul, for non-payment of allotment money of Rs 6 per share (including premium). Out of these, 800 shares were reissued at Rs 7 per share, Rs 8 paid up.

Short-term highly liquid investments qualify as cash equivalents if they are realisable into known amounts of cash from the date of acquisition within a period of :