List of top Chemistry Questions asked in KEAM

A research scholar returned to the laboratory after the lock down due to Covid-19. He kept acetone, benzaldehyde, acetaldehyde and diethyl ketone in four different bottles. The bottles contained only the label as P, Q, R and S. He forgot which bottle contained which compound. Compounds P and R only underwent iodoform test. Compound R alone gave reddish brown precipitate with Fehling's reagent. Compounds Q and R alone underwent Tollen's test. Compound S did not answer any of the above tests. Identify the compounds P, Q, R and S.
Compounds 'A', 'B' and 'C' have the same molecular formula C_7H_8O. Compound 'A' and 'B' liberate hydrogen gas with sodium metal. When treated with sodium hydroxide, compound 'B' alone dissolves. Compound 'C' is inert towards both sodium metal and sodium hydroxide. Compounds 'A', 'B' and 'C" are respectively
Which one of the following is not correct with respect to properties of amines?
Compound 'A' is obtained by the reaction of benzyl chloride with magnesium metal in dry ether followed by treatment with water. What is the compound 'A"?
The reagent that is used to convert but-2-yne to trans-but-2-ene is
Maximum number of photons emitted by a bulb capable of producing monochromatic light of wavelength $550\, nm$ is ..........., if $100\, V$ and $1\, A$ is supplied for one hour.
The standard heat of formation of $CH_4, CO_2$ and $H_2O (I)$ are $ -76.2, -394.8$ and $-285.82\, kJ\, mol^{-1}$, respectively. Heat of vaporization of water is $44\, kJ\, mol^{-1}$. Calculate the amount of heat eveolved when $22.4\, L$ of $CH _4$, kept under normal conditions, is oxidized into its gaseous products
The Henry�s law constant for $O_2$ dissolved in water is $4.34 \times 10^4$ atm at certain temperature. If the partial pressure of $O_2$ in a gas mixture that is in equilibrium with water is 0.434 atm, what is the mole fraction of $O_2$ in the solution?
On passing silent electric discharge through oxygen in an ozonizer, $5.5\, mol \%$ of oxygen is converted to ozone. How many moles of $O_2$ and $O_3$ result when $35$ moles of $O_2$ is originally present?
Which of the following compounds are aromatic?
Which statement(s) is (are) false for the periodic classification of elements?
A solution contains 4 g of NaOH and 16.2 g of water. The mole fraction solute and solvent are respectively
The pH of a solution obtained by mixing 60 mL of 0.1 M BaOH solution at 40m of 0.15m HCI solution is
The equilibrium constant for the following reactions $N_2(g) + 3H_2(g) \rightleftharpoons 2NH_3(g), N_2(g) +O_2(g) \rightleftharpoons 2NO(g)$ and$ H_2(g) + \frac{1}{2} O_2(g) \rightleftharpoons H_2O(1g)$ are K1, K2 and K3 respectively. The equilibrium constant (K) for the reaction
A compound 'A'with molecular formula \({C_5H_{10}O}\)gives a positive \({2,4-DNP}\) test but a negative Tollen's test. On treatment with sodium hypochlorite, it gives \({CHCl_3}\) and compound 'B'. Compound 'B' is
The hybridized state of $Al^{3+}$ in the complex ion formed when $AlCl_3$ is treated with aqueous acid is
One mole of hydrazine $(N_2H_4)$ loses $10$ moles of electrons in a reaction to form a new compound $X$. Assuming that all the nitrogen atoms in hydrazine appear in the new compound, what is the oxidation state of nitrogen in $X$ ? (Note: There is no change in the oxidation state of hydrogen in the reaction)
Narcotic analgesic is
Which one of the following is a benzenoid aromatic compound?
One of the builders present in scouring soaps?
The rate constant of the reaction $2N_2O_5 \rightarrow 4NO_2 + O_2$ at $300\,K$ is $3 \times 10^{-5}\,s^{-1}$. If the rate of the reaction at the same temperature is $2.4 \times 10^{-5}\, mol\, dm^{-3}\, s^{-1}$, then the molar concentration of $N_2O_5$ is
What are the constituents present in German silver?
Which one of the following is a non-reducing sugar?
Which one of the following exhibits positive resonance effect (+R effect)?
Which one of the following is an achiral molecule?