29.5 mg of an organic compound containing nitrogen was digested according to Kjeldahl’s method and the evolved ammonia was absorbed in 20 mL of 0.1 M HCl solution. The excess of the acid required 15 mL of 0.1 M NaOH solution for complete neutralization. The percentage of nitrogen in the compound is

The correct order of increasing basicity of the given conjugate bases (R = CH3) is

Out of the following, the alkene that exhibits optical isomerism is

The standard enthalpy of formation of NH3 is –46.0 kJ mol–1. If the enthalpy of formation of H2 from its atoms is –436 kJ mol–1 and that of N2 is –712 kJ mol–1, the average bond enthalpy of N–H bond in NH3 is :

For a particular reversible reaction at temperature T, ∆H and ∆S were found to be both +ve. If Te is the temperature at equilibrium, the reaction would be spontaneous when :

One mole of a symmetrical alkene on ozonolysis gives two moles of an aldehyde having a molecular mass of 44 u. The alkene is

If sodium sulphate is considered to be completely dissociated into cations and anions in aqueous solution, the change in freezing point of water (∆Tf), when 0.01 mol of sodium sulphate is dissolved in 1 kg of water, is (Kf = 1.86 K kg mol–1)

On mixing, heptane and octane form an ideal solution. At 373 K, the vapour pressures of the two liquid components (heptane and octane) are 105 kPa and 45 kPa respectively. Vapour pressure of the solution obtained by mixing 25.0g of heptane and 35 g of octane will be (molar mass of heptane = 100 g mol–1 and of octane = 114 g mol–1)

In aqueous solution the ionization constants for carbonic acid are K1 = 4.2 x 10–7 and K2 = 4.8 x 10–11 Select the correct statement for a saturated 0.034 M solution of the carbonic acid.

In the chemical reactions, the compounds $${}^{\prime }{A}^{\prime }$$ and $${}^{\prime }{B}^{\prime }$$ respectively are

The correct order of $$E_{M^{2+}/M}^o$$ values with negative sign for the four successive elements Cr, Mn, Fe and Co is :

The Gibbs energy for the decomposition of Al2O3 at 500oC is as follows : {2 \over 3}A{l_2}{O_3} $$\to$$ {4 \over 3}Al + {O_2}, $${\Delta }_{r}G$$ = + 966 kJ mol–1 The potential difference needed for electrolytic reduction of Al2O3 at 500oC is at least :

The polymer containing strong intermolecular forces e.g. hydrogen bonding, is

Biuret test is not given by

Let A and B denote the statements A: $$\cos \alpha +\cos \beta +\cos \gamma =0$$ B: $$\sin \alpha +\sin \beta +\sin \gamma =0$$ If \cos \left( {\beta - \gamma } \right) + \cos \left( {\gamma - \alpha } \right) + \cos \left( {\alpha - \beta } \right) = - {3 \over 2}, then:

Let $$A$$ be a $$2\times 2$$ matrix Statement - 1 : $$adj\left(adjA\right)=A$$ Statement - 2 :$$\left|adjA\right|=\left|A\right|$$

Let $$a,b,c$$ be such that $$b\left(a+c\right)\ne 0$$ if \left| {\matrix{ a & {a + 1} & {a - 1} \cr { - b} & {b + 1} & {b - 1} \cr c & {c - 1} & {c + 1} \cr } } \right| + \left| {\matrix{ {a + 1} & {b + 1} & {c - 1} \cr {a - 1} & {b - 1} & {c + 1} \cr {{{\left( { - 1} \right)}^{n + 2}}a} & {{{\left( { - 1} \right)}^{n + 1}}b} & {{{\left( { - 1} \right)}^n}c} \cr } } \right| = 0 then the value of $$n$$ :

In a binomial distribution B\left( {n,p = {1 \over 4}} \right), if the probability of at least one success is greater than or equal to {9 \over {10}}, then $$n$$ is greater than :

One ticket is selected at random from $$50$$ tickets numbered $$00,01,02,....,49.$$ Then the probability that the sum of the digits on the selected ticket is $$8$$, given that the product of these digits is zer, equals :

Let $$y$$ be an implicit function of $$x$$ defined by $$x^{2x}-2x^x\cot y-1=0$$. Then $$y^{\prime }(1)$$ equals