Question

An enzyme contains $5.6\%$ Fe, Calculate the number of Fe atoms present in $1g$ of the enzyme.

• A. $12.044\times {10}^{20}$
  
• B. $6.022\times {10}^{20}$
  
• C. $6.022\times {10}^{21}$
• D. none of these

Answer 1

The correct option is B

$6.022\times {10}^{20}$

$5.6\%$ Fe $\to 1g$ enzyme $\to 1\times \frac{5.6}{100}=56\times {10}^{-3}g$

atomic mass of Fe$=56u$

$56g\to 1$ mole atoms

$56\times {10}^{-3}g\to {10}^{-3}$ mole atoms

${10}^{-3}\times 6.022\times {10}^{23}=6.022\times {10}^{20}$ atoms