List of top Chemistry Questions

An ore after levigation is found to have basic impurities. Which of the following can be used as flux during smelting ?
An open vessel containing air is heated from 27$^\circ$C to 127$^\circ$C. The fraction of air originally present which goes out of it is
An open flask contains air at $27^?C$, calculate the temperature to which it should be heated such that one third of air measured at final temperature escapes out.
An oil-soluble dye is mixed with an emulsion and emulsion remains colourless. Then, it is
An ionic solid is a poor conductor of electricity because
An example of alum is
An example of a neutral oxide is
An emulsion is a colloidal solution of one of the following dispersed in another liquid
An element with mass number $81$ contains $31.7\%$ more neutrons as compared to protons. Find the symbol of the atom
An element $X$ has atomic number $19$. What will be the formula of its oxide?
An element in +3 oxidation state has the electronic configuration (Ar) $3d^3$. Its atomic number is
An element of group $14$ forms two oxides one of which is highly poisonous and neutral. Other oxide can be easily liquefied and compressed to give a solid which is used as a refrigerant under the name of drikold. The element and the oxides are
An element $'P'$ has atomic number $56$. What will be the formula of its halide?
An element crystallises in a structure having a $fcc$ unit cell of an edge $200\,pm$. If $200\,g$ of this element contains $24 \times 10^{23}$ atoms then its density is
An electron is in one of the $3d$-orbitals. What are the possible values of $n$, $l$ and $m$ for this electron?
An electrolytic cell contains a solution of $Ag_2SO_4$ and have platinum electrodes. A current is passed until 1.6 gm of $O_2$ has been liberated at anode. The amount of silver deposited at cathode would be
An electric current is passed through silver voltameter connected to a water voltmeter. The cathode of the silver voltameter is 0.108 g moreat the end of the electrolysis. The volume ofoxygen evolved at STP is :
An arsenious sulphide sol carries a negative charge. The maximum precipitating power for this sol is possessed by
An aqueous solution of sodium carbonate is' alkaline because sodium carbonate is a salt of
An antibiotic contains nitro group attached to aromatic nucleus in its structure. It is
An amorphous solid $(X)$ burns in air to form a gas $(Y)$ which turns lime water milky. This gas decolourises aqueous solution of acidified $KMnO_4$. Gas $(Y)$ reacts with oxygen to give another gas $(Z)$ which is responsible for acid rain. $X$, $Y$ and $Z$ are
An alkyl halide, $RX$ reacts with $KCN$ to give propane nitrile. $RX$ is
An alcohol $(A)$ on dehydration gives $(B)$ which adds bromine molecule to give $(C). (C)$ on heating with sodamide gives $(D)$ which on hydration in the presence of $Hg^{++}/H_{2}SO_{4}$ gives $(E). E$ on reduction by lithium aluminium hydride gives $(A). (E)$ is also obtained on dry distillation of calcium salt of acetic acid. How many enolisable proton present in the product $(E)$?
An aldehyde on oxidation gives
An acidified solution of potassium permanganate oxidizes