hen a mixture of \(K _2 Cr _2 O _7\) and NaCl is warmed with concentrated \(H _2 SO _4\), red vapours of \((A)\) are evolved, which turn NaOH yellowish due to formation of compound (B). A and B respectively are:

\(\text{C}_3\text{H}_6\text{O}\) does not form a silver mirror with Tollen's reagent but forms an oxime with hydroxylamine. It can give positive:

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The speed at which a chemical reaction takes place is called the rate of reaction. The rate of reaction depends on various factors like concentration of the reactants, temperature, etc. The relation between the rate of reaction and the concentration of reacting species is represented by the equation r = k[A]^x[B]^y, where x and y are the order of the reaction with respect to the reactants A and B, respectively. The overall order of the reaction is x + y. The rate of reaction can also be increased by the use of a catalyst which provides an alternate pathway of lower activation energy. It increases the rate of forward and backward reaction to an equal extent. It does not alter the Gibbs energy of the reaction.
The role of a catalyst is to change

Match List-I (compound) with List-II (reagent or chemical test)

List-I (Compound)	List-II (Reagent or Chemical test)
(A) Phenols	(I) Tollen's test
(B) Amines	(II) \(NeutralFeCl _3 aq\). solution
(C) Aldehydes	(III) Iodoform Test
(D) Methyl Ketones	(IV) Hinsberg's Test

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The concentration dependence of the rate of a reaction is called the differential rate equation. It is not always convenient to determine the instantaneous rate, as it is measured by calculating the slope of the tangent at point 't' in the concentration vs time plot. This makes it difficult to determine the rate and hence the order of the reaction. This difficulty is overcome by integrating the differential rate equation. This integrated rate equation gives a direct relation between concentrations at different times and the rate constant. The integrated rate equations are different for the reactions having different reaction orders.
A certain amount of \(N _2 O _5\) decomposes to half of its initial amount in 50 minutes.
If the decomposition is a first order reaction, the rate constant of the reaction is.

Collision frequency is :

Which of following is a correct statement ?

The output voltage of an ideal transformer connected to 240 V a.c. mains is 24 V. When this transformer is used to light a bulb with ratings 24 V, 24 W, the primary current would be-

After industrialization in 1920 in England, the proportion of dark winged and white winged moths reversed because of:

Answer the question on basis of passage given below :
Molecular nitrogen is very little reactive chemically. During lightning discharge, atmospheric nitrogen and oxygen combines to form nitric oxide which also combines with oxygen to form nitrogen dioxide. Both NO and \(NO _2\) constitute smog which is very poisonous. It can cause burning sensation in the eyes and adversely affect respiratory system.
What is the value associated with control of photo chemical smog?

Which of the following statement/s is/are wrong?
A. Methylamine is more basic than ammonia.
B. Amines form hydrogen bonds.
C. Ethylamine has higher boiling point than propane.
D. Dimethylamine is less basic than methylamine.
E. Amines are soluble in organic solvents like alcohol.
Choose the correct from the options given below:

Process of formation of new species due to change in allele frequency in a population is called:

The differential equation whose solution is \(A x^2+B y^2=1\) where \(A\) and \(B\) are arbitrary constant is of:
(A) first order and first degree
(B) second order and first degree
(C) second order and second degree
(D) second order
Choose the correct answer from the options given below :