Question

What mass of FeSO4^2- x 6H20 (Molar Mass=260g/mol) is required to produce 500 mL of a .10M iron (II) sulfate solution.

A.) 9g
B.) 13g
C.) 36g
D.) 72g

Answer 1

The correct option is: B. 13g

Step-by-step explanation:

Given: Molar mass of iron (II) sulfate: m = 260g/mol,

Molarity of iron (II) sulfate solution: M = 0.1 M,

Volume of iron (II) sulfate solution: V = 500 mL = 500 × 10⁻³ = 0.5 L (∵ 1L = 1000mL)

Mass of iron (II) sulfate taken: w = ? g

Molarity:
`M = (n)/(V (L)) = (w)/(m* V(L))`

Here, n- total number of moles of solute, w - given mass of solute, m- molar mass of solute, V- total volume of solution in L

∴ Molarity of iron (II) sulfate solution:
`M = (w)/(m* V(L))`

⇒
`w = M* m* V(L)`

⇒
`w = (0.1 M)* (260g/mol)* (0.5L)`

⇒ mass of iron (II) sulfate taken:
`w = 13 g`

Therefore, the mass of iron (II) sulfate taken for preparing the given solution is 13 g.