Identify the essential amino acids from the following.
(A) Threonine
(B) Serine
(C) Histidine
(D) Lysine
Choose the correct answer from the options given below :

Which of the following represents Fehling solution B?

The reaction occurring at the cathode during discharging of a lead-storage battery is:

Read the Passage carefully and answer the Questions
Kinetic studies not only help us to determine the rate of a chemical reaction but also describe the conditions by which the reaction rates can be altered. The factors such as concentration, temperature, pressure and catalyst affect the rate of a reaction.
The speed of a reaction or the rate of a reaction can be defined as the change in concentration of a reactant or product in unit time.
Rate \(=k[A]^x[B]^y\)
Here \(k\) is the rate constant
\(x+y\) gives the overall order of a reaction, whereas \(x\) and \(y\) represent the order with respect to the reactants \(A\) and \(B\), respectively.
Which of the following statements are correct?
(A) Catalysts increase the rate of a chemical reaction.
(B) Catalysts can catalyze both spontaneous and non-spontaneous reactions.
(C) Higher the activation energy for a chemical reaction, lower is the rate of the reaction.
(D) Catalyst increases the potential energy barrier.
Choose the correct answer from the options given below:

Aniline upon heating with concentrated \(HNO_3\) and concentrated \(H_2SO_4\) mixture gives:

Correct order of boiling points in the following is :
(A) \(CH_3CHO\)
(B) \(CH_3COOH\)
(C) \(CH_3CH_2OH\)
(D) \(CH_3CH_3\)
(E) \(CH_3CH_2Cl\)
Choose the correct answer from the options given below :

Answer the question on basis of passage given below :
Look at the following chemical reactions and answer the following question :
(A) \(C_7H_8 \xrightarrow{\text{Conc. HNO}_3, 0^\circ C}
(B) \xrightarrow{Sn/HCl}
(C) \xrightarrow{NaNO_2/H_3O^+}
(D) \xrightarrow{H_2O, Heat} (E)\)
(E) \(CH_3I \xrightarrow{KMnO_4/H^+}
(F) \xrightarrow{H_3O^+} (G) \xrightarrow{NaOH} (H)\)
Which of the following compounds will undergo coupling reaction ?

Read the following passage given below and answer the question.
Production of electricity by thermal plants is not very efficient method. It is now possible to make cells in which reactants are fed continuously to the electrodes and products are also removed continuously. One of the most successful fuel cells is hydrogen fuel cell.
Which of the following statement is correct regarding hydrogen fuel cells?

If \(\begin{vmatrix} 2 & 3 & 2 \\ x & x & x \\ 4 & 9 & 1 \end{vmatrix} + 3 = 0\) then the value of x is:

Let \(A =\left[a_{i j}\right]\) be a \(2 \times 2\) matrix such that \(a_{i j}=\frac{|-3 i+j|}{2}\) then \(a_{21}\) is :

Which of the following material is a semiconductor?

According to the IUCN, the total number of plant and animal species is about :-

In RNA interference (RNAi) the genes are silenced using: