What volume of $NH_3$ gas at $STP$ would be needed to prepare $100 \ mL$ of $2.5$ molal $(2.5 \ m)$ ammonium hydroxide solution? (Assume the density of the solution is $1 \ g/mL$)

$16 \ g$ each of $H_2$,$He$,and $O_2$ are present in a container exerting $10 \ atm$ pressure at $T \ (K)$. The pressure in $atm$ exerted by $16 \ g$ each of $He$ and $O_2$ in the second container of same volume and temperature is

Which of the following formulas is correctly represented according to Stock notation?

Calculate the number of moles of $NaOH$ required to completely neutralize $100 \ g$ of $118\%$ oleum.

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 :

Identify the type of reaction for the following chemical equation:
$CuSO_4 + 2NaOH (excess) \longrightarrow Cu(OH)_2 \downarrow + Na_2SO_4$