The reaction of calcium with water is represented by the equation $Ca + 2H_2O \to Ca(OH)_2 + H_2$. What volume of $H_2$ at $STP$ would be liberated when $8 \ g$ of calcium completely reacts with water? .......... $cm^3$

$4.0 \, g$ of caustic soda is dissolved in $100 \, mL$ of solution. The normality of the solution is: (in $, N$)

What is the number of moles of water removed from one mole of cane sugar when charred completely using conc. $H_2SO_4$?

One litre of hard water contains $12.00 \ mg$ of $Mg^{2+}$. The milli-equivalents of washing soda $(Na_2CO_3)$ required to remove its hardness is:

Fortification of food with iron is done using $FeSO_4 \cdot 7 H_2 O$. The mass in grams of the $FeSO_4 \cdot 7 H_2 O$ required to achieve $12 \ ppm$ of iron in $150 \ kg$ of wheat is $..........$ (Nearest integer).
[Given: Molar mass of $Fe, S$ and $O$ respectively are $56, 32$ and $16 \ g \ mol^{-1}$]

$A$ mixture of $CaCl_{2}$ and $NaCl$ weighing $4.44 \ g$ is treated with sodium carbonate solution to precipitate all the $Ca^{2+}$ ions as calcium carbonate. The calcium carbonate so obtained is heated strongly to get $0.56 \ g$ of $CaO$. The percentage of $NaCl$ in the mixture (atomic mass of $Ca=40$) is