List of top Chemistry Questions

The role of calcination in metallurgical operation is
The relative abundance of two isotopes of atomic weight 85 and 87 is 75% and 25% respectively. The average atomic weight of element is
The repeating units of PTFE are
The reducing agent used in the thermite process is
The recoil speed of a hydrogen atom after it emits a photon in going from $n = 5$, state to $n = 1$ state is
The radius of the nuclues is proportional (if A is the atomic mass number)
The radius of $n^{th}$ orbit $r_n$ in terms of Bohr radius $(a_0)$ for a hydrogen atom is given by the relation
The purpose of smelting an ore is
The name hydrogen was given by
The maximum amount of $BaSO_4$ precipitated on mixing $BaCl_2 (0.5 M)$ with $H_2SO_4$(1 M) will correspond to
The hydroxide of which of the following element is amphoteric?
The hydride ion, $H^-$, is a stronger base than the hydroxide ion, $OH^-$. Which one of the following reactions will occur if sodium hydride (NaH) is dissolved in water?
The hybridisation and geometry of $ B $ and $ N $ in $ [H_3B {
The helium atom does not contain
The heat of transition is the heat evolved or absorbed when a substance is converted from
The ground state electronic configuration of neutral titanium atom is
The ground state electronic configuration of $S$ is $3s^2 3p^4$. How does it form the compound $SF_6$?
The Government of India has passed the environment (Protection) Act in the year
The gold numbers of four protective colloids O, P, Q and R are 0.005, 0.01, 0.1 and 0.5 respectively. The decreasing order of their protective power is
The formula of sodium zeolite which is used in permutit process for softening water is
The formula for permutit or zeolite which is used as softner in ion-exchange method is
The following reaction is known as $ {C6H6 + CH3Cl ->[AlCl_3][(\text{anhy}.)] C6H5CH3 + HCl}$
The first ionization energies of group 16 elements
The first line of the Lyman series in a hydrogen spectrum has a wavelength of $1210 ??. The corresponding line of a hydrogen- like atom of $Z = 11$ is equal to
The fire extinguisher 'pyrene' contains