The amount of calcium oxide produced on heating $150 \ kg$ of limestone ($75 \%$ pure) is $........... \ kg$ $(Nearest \ integer)$. Given: Molar mass (in $g \ mol^{-1}$) of $Ca = 40, O = 16, C = 12$.

If $6.022 \times 10^{20}$ atoms are present in $100 \ mL$ of urea solution,then find out the molarity of the urea solution. (in $M$)

Consider the reaction shown below. The percentage yield of the amide product is $......$ . (Round off to the Nearest Integer). (Given: Atomic mass: $C = 12.0 \, u, H = 1.0 \, u, N = 14.0 \, u, O = 16.0 \, u, Cl = 35.5 \, u$)
$C_6H_5COCl + (C_6H_5)_2NH \rightarrow C_6H_5CON(C_6H_5)_2 + HCl$
Given: $0.140 \, g$ of $C_6H_5COCl$ reacts with $0.388 \, g$ of $(C_6H_5)_2NH$ to produce $0.210 \, g$ of $C_6H_5CON(C_6H_5)_2$.

$4.0 \ g$ of a mixture containing $Na_2CO_3$ and $NaHCO_3$ is heated to $673 \ K$. The loss in mass of the mixture is found to be $0.62 \ g$. The percentage of sodium carbonate in the mixture is:

The density of $2 \ M$ aqueous solution of $NaOH$ is $1.28 \ g \ cm^{-3}.$ The molality of the solution is $... \ m$ [Given that molecular mass of $NaOH = 40 \ g \ mol^{-1}$]

If $0.45 \ g$ of a gas with molecular weight $60$ and $0.22 \ g$ of another gas with molecular weight $44$ are present,and the total pressure exerted by the mixture is $75 \ cm \ Hg$,then the partial pressure of the second gas is .......... $cm$ of $Hg$.