Calculate the molar solubility of fe(oh)2 in pure water. (the value of ksp for fe(oh)2 is 4.87×10−17.) express the molar solubility in moles per liter to two significant figures. m

When Fe(OH)2 (S) ↔ Fe2+   +   2OH- is the reaction equation

let the molar solubility = X

when mol/L Fe(OH)2   gives X mol / L Fe2+ and 2X mol / L OH-

when the Ksp expression is:

Ksp = [Fe2+] [OH-]^2

when we assume [Fe2+] = X 

and [OH-] = 2X

and when we have Ksp = 4.87 x 10^-17

so by substitution:

∴ 4.87 x 10^-17 = X*(2X)^2

∴ 4X^3 = 4.87 x 10^-17

∴X = 2.3 x 10^-6

∴ the molar solubility = X = 2.3 x 10^-6  mol/L

Most likely a is the answer - because  you generate   38 atp's but also consume an atp.   each atp gives approx. less than 4 kcal so probably a is the closest answer.

You use the atomic number to find out how many protons and neutrons there are in the atom. you use the atomic mass to find out how many protons and electrons there are in the atom.