List of top Chemistry Questions

A reaction involving two different reactants can never be

Consider an endothermic reaction $X\, \to \,Y$ with the activation energies $E_b$ and $E_f$ for the backward and forward reactions respectively. In general :

The rate constant of a reaction depends on:

The temperature coefficient of a reaction is 2. If the velocity of the reaction is 5 at 25�C, then, the velocity of the reaction at 55�C is

If $2.0 \,g$ of a radioactive isotope has a half-life of $20\, h$, the half-life of $0.25 \,g$ of the same substance is:

Law of multiple proportions is illustrated by one of the following pairs:

The amount of calcium carbonate that reacts with 500 cc of 0.5 N hydrochloric acid is

On reduction with hydrogen, $3.6\, g$ of an oxide of metal left $3.2\, g$ of metal. If the vapour density of metal is $32$, the simplest formula of the oxide would be

In electrolysis of dilute $ H_2SO_4$, what is liberated at anode?

A current of strength $2.5$ amp was passed through $CuSO _{4}$ solution for 6 minutes $26$ seconds. The amount of copper deposited is : (At. wt. of $Cu =63.5,1\, F =96500$ coulomb $)$

Orbital is :

Which of the following is not hydrolysed?

The isoelectronic pair is

The number of isomeric hexanes is:

Due to the presence of an unpaired electron, free radicals are:

Among the following the strongest nucleophile is

Which types of isomerism is shown by $2, 3$-dichlorobutane ?

At $90^{\circ} C$, pure water has $H _{3} O ^{+}$ion concentration of $10^{-6} mol / L ^{-1}$. The $K_{w}$ at $90^{\circ} C$ is :

For the reaction $ {2NO2(g) <=> 2\,NO(g) + O2(g)}$ $\left(K_{c} = 1.8\times10^{-6} \,at \,184^{\circ}C\right)$ $\left(R = 0.00831 \,k J/\left(mol. K\right)\right)$ When $K_{p}$ and $K_{c}$ are compared at $184^{\circ}$ C it is found that :

Hydrogen ion concentration in mol/L in a solution of pH = 5.4 will be :

What is the conjugate base of $OH^-$ ?

When $10\, mL$ of $0.1\, M$ acetic acid $(pK_{a} = 5.0)$ is titrated against $10\, mL$ of $0.1\, M$ ammonia solution $(pK_{b} = 5.0)$, the equivalence point occurs at $pH$

Hydrogen bomb is based on the principle of :

The material used in warfare in making smoke screens for military purposes is:

Glucose has difference from fructose in that it