Class 12th

Which technique among the following is most appropriate in separation of a mixture of 100mg of p-nitrophenol acid  and picric acid?

For the reaction

H₂F₂(g) ® H₂(g) + F₂(g)

$\Delta U=-59.6kJmo{l}^{-1}at27°C$

The enthalpy change for the above reaction is ()__________kJ mol^-1. [nearest integer]

A wire of length L is hanging from a fixed support. The length changes to L₁ andL₂ when masses 1kg and 2kg are suspended respectively from its free end. Then the value of L is equal to:

 + CH₄  --> A + B

A and B in the above atmosphere reaction step are:

The dark purple colour KMnO₄ disappears in the titration with oxalic acid in acidic medium. The overall change in the oxidation number of manganese in the reaction is:

Consider an imaginary ion  The nucleus contains 'a'% more neutrons that the number f electrons in the ion. The value of 'a' is____________. [nearest integer]

Which of the given reactions is not an example of disproportionation reaction?

A 10g mixture of hydrogen and helium is contained in a vessel of capacity 0.0125 m³ at 6 bar ansd $27°$ C. The mass of helium in the mixture is__________g. (nearest integer)

Borazine, also known as inorganic benzene, can be prepared by the reaction of 3-equivalents of “X” with 6-equivalents of “Y”. 'X' and “Y”, respectively are:

Reaction of BeCl₂ with LiAlH₄ gives:

(A) AlCl₃

(B) BeH₂

(C) LiH

(D) LiCl

(E) BeAlH₄

Choose the correct answer from options given below: