List of top Chemistry Questions

A flask containing air (open to the atmosphere) is heated from 300 K to 500 K. The percentage of air escaped to the atmosphere is
A dispersion of AgCl in water is
A diode used as a rectifier is
A current of 9.65 ampere flowing for 10 minutes deposits 3.0 g of the metal which is monovalent. The atomic mass of the metal is
Bakelite is obtained from phenol by reacting with
Which of the following is not a condensation polymer ?
A compound is formed by two elements $Y$ and $Z$. The element $Z$ forms $ccp$ and atoms $Y$ occupy $1/3\, rd$ of tetrahedral voids. The formula of the compound is
A compound 'A' having the molecular formula $C_5H_{12}O$ on oxidation gives a compound 'B' with molecular formula $C_5H_{10}O$. Compound 'B' gave a 2, 4-DNP derivative but did not give the haloform test. The structure of the compound A is
A compound $(A)$ of molecular formula $C_7H_8O$ is insoluble in water and dilute sodium bicarbonate but dissolves in dilute aqueous sodium hydroxide and gives a characteristic colour with aqueous $FeCl_3$. On treatment with bromine water, it readily gives a precipitate of $C_7H_5OBr_3$. Write down the structure of the compound $(A)$.
A compound is formed by two elements X and Y. Atoms of the element Y (as anions) make ccp and those of the element X (as cations) occupy all the octahedral voids. What is the formula of the compound?
A compound $'A'$ having the molecular formula $C+{5}H_{12}O$, on oxidation gives a compound $'B'$ with molecular formula $C_{5}H_{10}O$. Compound $'B'$ gave a $2,4-$dinitrophenylhydrazine derivative but did not answer haloform test or silver mirror test. The structure of compound $'A'$ is
If the melting point of ice is $0^?C$ and latent heat of fusion is $5.46\, kJ\, mol^{-1}$, the entropy change for the conversion of $18\, g$ of ice to water at one atmosphere is
A complex involving $dsp^2$ hybridisation has
A combustible gas is liberated when caustic soda solution is heated with
A colloid always :
A colloidal system having a solid substance as a dispersed phase and a liquid as a dispersion medium is classified as_____________ .
A chemical $'A?$ is used for the preparation of washing soda to recover ammonia. When $CO_2$ is bubbled through an aqueous solution of $'A?$, the solution turns milky. It is used in white washing due to disinfectant nature. What is the chemical formula of $'A'$ ?
A chelating agent has two or more than two donor atoms to bind to a single metal ion. Which of the following is not a chelating agent?
A certain current liberate 0.5 g of hydrogen in 2 h. How many grams of copper can be liberated by the same current flowing for the same time in a copper sulphate solution ?
A certain compound $X$ imparts a golden yellow flame. When zinc powder is heated with concentrated solution of $X$, $H_2$ gas is evolved. $X$ combines with $CO_2$ to give a salt $Y$. $Y$ is a hydrated salt which on reaction with $HCl$ or excess of $CO_2$ gives another salt $Z$ which is an important part of baking powder. Identify $X$, $Y$ and $Z$.
A certain compound has a formula $ {C_3H_6O}$. It combines with hydroxylamine to form two compounds which are geometrical isomers of each other. It is
A box of T L-capacity ls'divided into two equal compartments by a thin partition which are filled with 2 g $H_2$ and 16 g $CH_4$ respectively. The pressure in compartment filled with $H_2$ is recorded as P atm. The total pressure when partition is removed will be
A black powder when heated with cone. $HCl$ gives a greenish yellow gas. The gas acts as an oxidising and a bleaching agent. When it is passed over slaked lime, a white powder is formed which is a ready source of gas. The black powder and white powder respectively are
A black compound of manganese reacts with a halogen acid to give greenish yellow gas. When excess of this gas reacts with $NH_3$ an unstable trihalide is formed. In this process the oxidation state of nitrogen changes from
A barbituric acid derivative drug Veronal is used as