List of top Chemistry Questions

Aromatic aldehydes in the presence of cyanide ion are convened to acyloins. This reactionis called
$[Ar]^{18} 3d^{10}4s^1$ electronic configuration belongs to
Aqueous tension of water depends on
Anti-Markovnikov?? addition of HBr is not observed in
Aniline reacts with which of these to form Schiff base ?
Anhydrous cobalt (II) chloride is blue in colour but on dissolving in water it changes to pink in colour because
Anhydrous $ {AlCl_3}$ is prepared from
Anhydrous stannous chloride can be prepared by
Analysis shows that an oxide ore of nickel has formula $Ni_{0.98} O_{1.00}$ The percentage of nickel as $Ni^{3+}$ ions is nearly
An oxide $X$ in its normal form is almost non- reactive due to very high $X - O$ bond enthalpy. It resists the attack by halogens, hydrogen and most of acids and metals even at elevated temperatures. It is only attacked by $HF$ and $NaOH$. The oxide $X$ is
An organic compound (A), $C_2H_5NO_2$ gives on reduction another compound (B) $C_2H_7N$. The reaction of nitrous acid on (B) evolves nitrogen and gives another compound (C) $C_2H_6O$. The compound (C) on oxidation gives acetic acid. The compounds A, B, C are
An organic compound with the formula $C_6H_{12}O_6$ forms a yellow crystalline solid with phenylhydrazine and gives a mixture of sorbitol and mannitol when reduced with sodium. Which among the following could be the compound ?
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?