Class 12th

The products obtained from a reaction of hydrogen peroxide and acidified potassium permanganate are

The metal that is not extracted from its sulfide ore is

The metal that has very low melting point and its periodic position is closer to a metalloid is

Given below are two statements : one is labeled as Assertion A  and the other is labeled as Reason R.

Assertion A: Finest gold is red in colour, as the size of the particles increase, it appears purple then blue and finally gold.

Reason R: The  colour of the colloidal solution depends on the wavelength of light scattered by the dispersed particles.

In the light of the above statements, choose the most appropriate answer from the options given below.

At $30°C,$ the half life for the decomposition of AB₂ is 200s and is independent of the initial concentration of AB₂. The time required for 80% of the AB₂ to decompose is

Match List – I and List – II.

Choose the correct answer from the options given below

Arrange the following in increasing order of heir covalent character.

(A). CaF₂                                         

(B). CaCl₂

(C) CaBr₂

(D) CaI₂

The nature of charge on resulting colloidal particles when FeCl₃ is added to excess of hot water is

Among the following the number of curves not in accordance with Freundlich adsorption isotherm is_________.

Hemoglobin contains 0.34% of iron by mass. The number of Fe atoms in 3.3g of hemoglobin is (Given: Atomic mass of Fe is 56 u, N_A = 6.022 * 10²³ mol^-1.)