Question

Calculate the number of formula units of $CuS{O}_4.5H_{2}O$ present in ${10}^{-13}$ moles of pure $CuS{O}_4.5H_{2}O$.

• A. $6.022\times {10}^{10}$
• B. $6.022\times {10}^{13}$
• C. $6.022\times {10}^{12}$
• D. $6.022\times {10}^9$

Answer 1

The correct option is A $6.022\times {10}^{10}$

We know,
1 mole of $CuS{O}_4.5H_{2}O=6.022\times {10}^{23}$ formula units of $CuS{O}_4.5H_{2}O$
So, ${10}^{-13}$ moles of pure $CuS{O}_4.5H_{2}O$
$=6.022\times {10}^{23}\times {10}^{-13}$ formula units $=6.022\times {10}^{10}$ formula units of $CuS{O}_4.5H_{2}O$