List of top Chemistry Questions

An alkene, \(\mathrm{C_3H_6}\) (X), on treatment with HBr in presence of peroxide gives (Y). The compound (Y) on treatment with \(\mathrm{AgNO_2}\) in ethanol gives (Z). The compounds (X), (Y) and (Z) are respectively
When sodium fusion extract is treated with sodium nitroprusside, the appearance of violet colour is due to the formation of
The formula of pentaamminecarbonatocobalt(III) chloride is
Which of the following compound of manganese is a mixed oxide?
The molar conductivity of a weak monobasic acid, HA at 298 K is \(70\ \text{S cm}^2\text{ mol}^{-1}\). What is the percentage ionisation of HA at 298 K?
At infinite dilution \(\lambda^\circ_{H^+} = 340\ \text{S cm}^2\text{ mol}^{-1}\) and \(\lambda^\circ_{A^-} = 80\ \text{S cm}^2\text{ mol}^{-1}\)
A first order reaction follows the equation \(k = (4 \times 10^{10}\ \text{s}^{-1}) e^{-2000/T}\). The value of \(E_a\) for the reaction is about (\(R = 8.314\ \text{J K}^{-1}\text{ mol}^{-1}\))
In a pseudo first order reaction, the following results were obtained. {|c|c|c|c|c|c|c|c|} Time s & 0 & 10 & 20 & 30 & 40 & 50 & 60
$[A]$/mol lit$^{-1}$ & 0.65 & 0.55 & 0.46 & 0.38 & 0.26 & 0.20 & 0.13
Average rate of the reaction between 20 and 40 seconds is
The percentage of helium present in air used by scuba divers is
The correct increasing order of enthalpy of fusion \(\Delta_{\text{fus}}H^\circ\) (in kJ mol\(^{-1}\)) of the following compounds is
The solubility product, \(K_{sp}\) of a sparingly soluble salt, \(\mathrm{AX_2}\), is \(3.2 \times 10^{-14}\) mol\(^3\) lit\(^{-3}\). Its solubility is
Match the correct pH value with the following substances:
(a) Milk of magnesia (i) pH = 6.8
(b) Black coffee (ii) pH = 7.8
(c) Egg white (iii) pH = 5
(d) Milk (iv) pH = 10
Which of the following bond has highest mean bond enthalpy?
The number of bonding pairs and lone pairs of electrons in \(\mathrm{BrF_5}\) molecule are respectively
The $\Delta_r G^\circ$ of the galvanic cell in which the following cell reaction takes place, \[ 2\mathrm{Cr(s)} + 3\mathrm{Cd^{2+}(aq)} \rightarrow 2\mathrm{Cr^{3+}(aq)} + 3\mathrm{Cd(s)} \] is ($E^\circ_{\mathrm{Cr^{3+}/Cr}} = -0.74$ V and $E^\circ_{\mathrm{Cd^{2+}/Cd}} = -0.40$ V)
In Mosley experiment, the X-ray spectrum is obtained by plotting
Which of the following elements have the highest and the lowest first ionization enthalpy?
(i) Be (ii) B (iii) C (iv) N (v) O
The correct increasing order of dipole moment of the following molecules is
The empirical formula of a metal oxide which has $54\%$ metal (M) and $46\%$ oxygen (O) is (Atomic mass of M = $27$ amu and O = $16$ amu)
The threshold wavelength of a metal is \(6000\ \text{\AA}\). The work function of the metal is (\(h = 6.62 \times 10^{-34}\ \text{J s}\))
The radius of the first orbit of \(\mathrm{He^+}\) is
If a radiation of energy $5.2$ eV falls on the photosensitive surfaces of Mo and Ni, they emit photoelectrons with maximum kinetic energy of $0.5$ eV and $1$ eV, respectively. Then the work function of
If the de Broglie wavelength associated with an electron is $0.1227$ nm, then its accelerating potential is
What is the de Broglie wavelength of an electron accelerated through a potential difference of \(100\,\text{V}\)?
Which of the following is the most acidic: Ethanol, Phenol, or \(o\)-Nitrophenol?
What is the ratio of the de Broglie wavelengths of an electron and a proton moving with the same velocity?