Question

Calculate the number of hydrogen atoms in $15$ moles of $H_{2}O?$

• A. $9.3\times {10}^{24}$
• B. $9.03\times {10}^{22}$
• C. $9.03\times {10}^{23}$
• D. $1.806\times {10}^{25}$

Answer 1

Answer: (D)

$1.806\times {10}^{25}$

$1$ mole of substance contains approximately $6.02\times {10}^{23}$ of its particles

$15.0$ moles of $H_{2}O$ have $15.0\times 6.02\times {10}^{23}=9.03\times {10}^{24}$ $H_{2}O$ molecules.

Each $H_{2}O$ molecule contains $2$ hydrogen atoms.

Total number of hydrogen atom$=2\times 9.03\times {10}^{24}=18.06\times {10}^{24}$ atoms.

$=1.806\times {10}^{25}$ atoms.

Hence, the correct option is D.