Class 12th

In $\stackrel{1}{C}{H}_2=\stackrel{2}{C}=\stackrel{3}{C}H-\stackrel{4}{C}{H}_3$ molecule, the hybridization of carbon 1,2,3 and 4 respectively are

Calgon is used for water treatment. Which of the following statement is NOT true about Calgon?

Ceric ammonium nitrate and CHCl₃/alc. KOH are used for the identification of functional groups present in…………. and……………respectively.

Which of the following is a correct statements?

           (a) Brownian motion destabilizes sols

           (b) Any amount of dispersed phase can be added to emulsion without establishing it.

           (c) Mixing two oppositely charged sols in equal amount neutralizes charges and stabilizes colloids.

           (d) Presence of equal and similar charges on colloidal particles provides stability to the colloidal solution.

The solubility of AgCl will be maximum in which of the following?

Arrange the following in the decreasing order of their covalent character:

           (A) LiCl
            (B) NaCl

          (C) KCl

           (D) CsCl

Choose the most appropriate answer from the options given below:

Production of iron in blast furnace follows the following equation

$F{e}_3{O}_4\left(s\right)+4CO\left(g\right)\to 3Fe\left(I\right)+4C{O}_2\left(g\right)$

When 4.640 kg of Fe₃O₄ and 2.520 kg of CO are allowed to react then the amount of iron (in g) produced is:

[Given : Molar Atomic mass (g mo^-1); Fe = 56

 Molar Atomic mass (g mol^-1); O = 16

Molar Atomic mass (g mol^-1); C = 12]

The number of solutions of the equation 2θ - cos²θ + $\sqrt[]{2}$ = 0 in R is equal to……….

The number of elements in the set

$S=\left\{\theta \in \left[-4\pi ,4\pi \right]:3co{s}^{2}2\theta +6cos2\theta -10co{s}^2\theta +5=0\right\}$ is…………….