Question

An enzyme contains 11.2%Fe by mass. The number of Fe atoms present in 1g of enzyme is

Answer 1

• The enzyme contains 11.2% Fe by mass, which means, 11.2 gm of Fe is present in 100 g enzyme.
• ​Since, the 100 gm enzyme contains 11.2 g of Fe, then, the 1 gm enzyme contains $\frac{11.2}{100}gFe=0.112gofFe$
• Therefore, the number of atoms present in 0.112 g of Fe can be calculated as:

$No.ofatomsofFe=\frac{Givenmass}{molarmassofFe}\times N_A$

$=\frac{0.112}{56}\times 6.022\times {10}^{23}$

$=1.2\times {10}^{21}atoms.$

Hence, the number of Fe atoms in 1 gm of enzyme-containing 11.2%Fe by mass $1.2\times {10}^{21}atoms.$