Chemistry - Concentration Terms Question with Solution | TestHub

$\begin{array}{rl}& \mathrm{M}=\frac{\mathrm{W}\times 1000}{{\mathrm{M}}_2\times \mathrm{V}\text{ (in }\mathrm{mL})}\\ & \mathrm{W}=\frac{\mathrm{M}\times {\mathrm{M}}_2\times \mathrm{V}\text{ (in }\mathrm{mL})}{1000}=\frac{0.75\times 36.5\times 25}{1000}\\ & =0.684\mathrm{g}\text{ (Mass of }\mathrm{HCl})\\ & \underset{36.5\mathrm{g}}{\mathrm{HCl}}+\underset{40\mathrm{g}}{\mathrm{NaOH}}⟶\mathrm{HCl}+\mathrm{NaOH}\end{array}$ 36.5 g HCl reacts with $\mathrm{NaOH}=40\mathrm{g}$ 0.684 g HCl reacts with $\mathrm{NaOH}=\frac{40}{36.5}\times 0.684\simeq 0.750\mathrm{g}$ Amount of NaOH left $=1\mathrm{g}-0.750\mathrm{g}=0.250\mathrm{g}=250\mathrm{mg}$