$H_2O_2$ solution used for hair bleaching is sold as a solution of approximately $5.0 \, g$ $H_2O_2$ per $100 \, mL$ of the solution. The molecular mass of $H_2O_2$ is $34$. The molarity of this solution is approximately $........$ $M$.

Which of the following substances represents calcium chlorite?

Assign $A, B, C, D$ from the given type of reaction.
$CaCl_2 + Na_2SO_4 \longrightarrow $ No reaction

The incorrect postulates of the Dalton's atomic theory are :
$A$. Atoms of different elements differ in mass.
$B$. Matter consists of divisible atoms.
$C$. Compounds are formed when atoms of different element combine in a fixed ratio.
$D$. All the atoms of given element have different properties including mass.
$E$. Chemical reactions involve reorganisation of atoms.
Choose the correct answer from the options given below :

What quantity (in $mL$) of a $45\%$ acid solution of a mono-protic strong acid must be mixed with a $20\%$ solution of the same acid to produce $800 \ mL$ of a $29.875\%$ acid solution?

When $1 \ L$ of $N/5 \ HCl$ aqueous solution in a beaker is boiled,the volume of the resulting solution becomes $250 \ mL$. During this process,$3.65 \ g$ of $HCl$ is lost. What will be the concentration of the resulting solution? $(HCl = 36.5 \ g/mol)$