Some Basic Concepts of Chemistry - Result Question 36 — JEE PYQ Chapterwise

Answer:

Correct Answer: 38. $\left(6.023 \times 10^{24}\right)$

Solution:

38. Considering density of water to be $1.0 \mathrm{~g} / \mathrm{mL}, 18 \mathrm{~mL}$ of water is $18 \mathrm{~g}(1.0 \mathrm{~mol})$ of water and it contain Avogadro number of molecules. Also one molecule of water contain

$\begin{aligned} 2 \times(\text { one from each H-atom }) & +8 \times(\text { from oxygen atom }) \\ & =10 \text { electrons. } \\ \Rightarrow 1.0 \text { mole of } \mathrm{H}_2 \mathrm{O} \text { contain } & =10 \times 6.023 \times 10^{23} \\ & =6.023 \times 10^{24} \text { electrons. } \end{aligned}$