Question

Calculate the mass of $12.0\times {10}^{14}$ atoms of hydrogen.

• A. $6.023\times {10}^{23}$ g
• B. $12\times {10}^{14}$ g
• C. $1.99\times {10}^{-9}$ g
• D. $9.33\times {10}^{22}$ g

Answer 1

Answer: (C)

$1.99\times {10}^{-9}$ g

Mass of $6.02\times {10}^{23}$ atoms of hydrogen = $1$ g
Therefore mass of $1$ atom of hydrogen = $\frac{1}{6.02\times {10}^{23}}$ g
$\therefore$ Mass of $12\times {10}^{14}$ atoms of hydrogen = $\frac{12\times {10}^{14}}{6.02\times {10}^{23}}$ = $1.99\times {10}^{-9}$g