Question

Spinach contains iron. Assume that one leaf has an area of 15 cm2 and has 7.3 x 105 atoms of iron per nm2 in it. Anne makes a spinach dish that has a volume of 5 L and uses 110 leaves of spinach. She needs to eat 3.2 x 10-4 moles of iron per day. How many pL of the dish would she have to eat in one day? (1 mole = 6.022 x 1023 atoms).

Answer 1

Moles of iron required= 3.2*10^-4

1 mole of iron contains 6.023*1023 atoms

3.2*10-4 moles contain 3.2*10^-4*6.023*10²³ atoms=1.92*10²⁰ atoms

1nm2 contains 7.3*10⁵ atoms

10¹⁵ cm2 contains 7.3*10⁵ atoms

15cm2 contains 15*7.3*10⁵/10¹⁵= 109.5*10^-10 atoms

number of leafs required/day= number of atoms requires/number of atoms in each leaf= 1.92*10²⁰/109.5*10^-10= 1.76*10²⁸

110 leaves correspond to 5L

1.76*1028 leaves correspond to 1.76*10²⁸*5/110=8*10²⁶L=8*10²⁶*10¹² pL= 8*10³⁸PL