List of top Chemistry Questions

The time required for 10% completion of a first order reaction at 298 K is equal to that required for its 25% completion at 308 K. If the value of A is \(4 \times 10^{10} s^{-1}\) . Calculate \(k\) at 318 K and \(E_a\).

The oxidation number of cobalt in \(K[Co(CO)_4]\) is

The following data were obtained during the first order thermal decomposition of \(SO_2Cl_2\) at a constant volume.
\(SO_2Cl_2(g) → SO_2(g) + Cl_2(g)\)

Experiment	Time/s-1	Total pressure/atm
1	0	0.5
2	100	0.6

Calculate the rate of the reaction when total pressure is 0.65 atm.

Predict the products of electrolysis in each of the following: 
 (i) An aqueous solution of AgNO₃ with silver electrodes. 
 (ii) An aqueous solution of AgNO₃ with platinum electrodes. 
 (iii) A dilute solution of H₂SO₄ with platinum electrodes. 
 (iv) An aqueous solution of CuCl₂ with platinum electrodes.

Nitric oxide reacts with Br₂ and gives nitrosyl bromide as per reaction given below:
\(2NO (g) + Br_2 (g) ⇋ 2NOBr (g)\)
When 0.087 mol of NO and 0.0437 mol of Br₂ are mixed in a closed container at constant temperature, 0.0518 mol of NOBr is obtained at equilibrium. Calculate equilibrium amount of NO and Br₂ .

Reaction of diborane with ammonia gives initially

A binary solid has a primitive cubical structure with $B^-$ ions constituting the lattice points and $A^+$ ions occupying $25\%$ of its tetrahedral holes. The molecular formula of the crystal is

Among the following, the optically active compound is

Sphalerite is concentrated by

IUPAC name of $ C{{H}_{3}}CH=\underset{\begin{align} & | \\ & C{{H}_{2}} \\ & | \\ & C{{H}_{3}} \\ \end{align}}{\mathop{C}}\,C{{H}_{3}} $

An atom with high electronegativity has

$1.5\, g$ of a non-volatile, non-electrolyte is dissolved in $50 \,g$ benzene $(K_b\, =\, 2.5\, K kg \,mol^{-1}$ ). The elevation of the boiling point of the solution is $0.75\, K$. The molecular weight of the solute in $g$ $mol^{-1}$ is

Ammonium ion $\left( NH _{4}^{+}\right)$ reacts with nitrite ion $\left( NO _{2}^{-}\right)$ in aqueous solution according to the equation $NH _{4}^{+}(a q)+ NO _{2}^{-}(a q) \longrightarrow N _{2}(g)+2 H _{2} O (l)$ The following initial rates of reaction have been measured for the given reactant concentrations. Which of the following is the rate law for this reaction?

A gas mixture contains 50% helium and 50% methane by volume. What is the percent by weight of methane in the mixture ?

For the reaction $ 2{{N}_{2}}{{O}_{5}}(g)\xrightarrow[{}]{{}}4N{{O}_{2}}(g)+{{O}_{2}}(g) $ if the concentration of $ N{{O}_{2}} $ increases by $ 5.2\times {{10}^{-3}} $ M in 100 s then the rate of the reaction is:

Complete combustion of 0.858 g of compound $ X $ gives 2.63 g of $ C{{O}_{2}} $ and 1.28 g of $ {{H}_{2}}O $ . The lowest molecular weight which $ X $ can have, is:

Ammonia will not form complex with

Syngas is a mixture of

$20.0 \,kg$ of $N_2(g)$ and $3.0\, kg$ of $H_2(g)$ are mixed to produce $NH_3(g)$. The amount of $NH_3(g)$ formed is

Excess nitrate in drinking water can cause

Amine that cannot be prepared by Gabriel- phthalimide synthesis is

Choose the reaction with negative $\Delta$S value

Hard acids prefer to combine with

Adsorption is accompanied by

A lone pair of electrons in an atom implies