Chemistry

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]

 + 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:

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

Assertion A: Phenolphthalein is pH dependent indicator, remains colourless in acidic solution and gives pink colour in basic medium.

Reason R: Phenolphthalein is a weak acid. It doesn't dissociate in basic medium.

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

Which of the following can be used to prevent the decomposition of H₂SO₄?