When water is added to quick lime,the reaction is

What are the different elements present in the mineral barite?

$A$ photon having a wavelength of $310 \ nm$ is used to break the bond of an $A_2$ molecule with a bond energy of $288 \ kJ \ mol^{-1}$. Calculate the percentage of the photon's energy that is converted into kinetic energy $(K.E.)$. [Given: $hc = 12400 \ eV \mathring{A}$,$1 \ eV/atom = 96 \ kJ/mol$]

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 $1 \ g/mL$)

$25 \ mL$ of $0.1 \ N \ NaOH$ solution neutralises $12.5 \ mL$ of $HCl$ solution. The amount of water needed to convert $500 \ mL$ of such $HCl$ solution to $0.1 \ N$ is (in $mL$)

You are given $500 \ mL$ of $2 \ N \ HCl$ and $500 \ mL$ of $5 \ N \ HCl$. What will be the maximum volume of $3 \ M \ HCl$ that you can make from these two solutions? .............. $mL$