Chemistry - Mole Concept Question with Solution | TestHub

Volume of one drop $=\left(\frac{1}{25}\right)\mathrm{mL}$ $\therefore$ Mass of $1\mathrm{drop}=\mathrm{V}\times \mathrm{d}$ $=\left(\frac{1}{25}\mathrm{mL}\right)(1\mathrm{g}/\mathrm{mL})$ $=\frac{1}{25}\mathrm{g}$ Number of moles of ${\mathrm{H}}_2\mathrm{O}=\frac{\text{ Massof water inonedrop }}{\text{ Molarmassof water }}=\frac{\frac{1}{25}}{18}=\frac{1}{25\times 18}$ $\therefore$ Number of ${\mathrm{H}}_2\mathrm{O}$ Molecule $=\frac{1}{25\times 18}{\mathrm{N}}_0=\frac{1}{50\times 9}{\mathrm{N}}_0=\frac{0.02}{9}{\mathrm{N}}_0$