Answer: 0.174 g
Explanation:
First of all understand that charge on an atom like here 2+ will not vary molar mass. because ions are formed by loss or gain of electrons and electrons do not contribute to the mass of an atom or ion. so losing or gaining electron doesnt create any difference.
molar mass of Fe, i.e. mass of 1 mole of Fe is 56 g. So, mass of 1 mole of Fe2+ will also be 56 g.
given is 0.003109 moles of Fe2+,
Use maths,
1 mole of Fe2+ weighs 56 g
So, 0.003109 moles will weigh = (56 g / 1 mol ) x 0.003109 = 0.174 g.
Answer : The molarity of 
in the solution is 1.5 M.
Explanation : Given,
Moles of = 3.0 mol
Volume of solution = 2.00 L
Molarity : It is defined as the number of moles of solute present in one liter of volume of solution.
Formula used :
Now put all the given values in this formula, we get:
Therefore, the molarity of in the solution is 1.5 M.
I believe the correct answer is C, but I'm 100% on this. Hope this helped though!
-TTL
There is the same overall number of atoms of each element on the reactants side as on the products side, they are simply rearranged. Also, mass is conserved as atoms cannot be created or destroyed by a chemical reaction.
