If 0.0490 mol of solid Al reacts stoichiometrically according to the balanced equation with 990 mL of aqueous Cl-, what molarity (M) of Cl- is required?
3 CuCl2(aq) + 2 Al(s) → 3 Cu + 2AlCl3(aq)
You have 0.0490 mole Al.
I assume that is 990 mL aq CuCl2. Moles CuCl2 needed = moles Al x (3 moles CuCl2/2 moles Al) = ??
M CuCl2 = moles/L = ?? moles/0.990 L.
The Cl^- must be 2x that. Check my thinking.
i did 0.049x2/3=mole of CuCl2
then mole of cucl2/.99 then times by 2 to get 0.0660 but its wrong, the actual answer is 0.148. Can you double check this again why i did it wrong
You messed up on the conversion. Look at my response again. It is 0.049 x (3/2) and that x 2 and NOT 0.049 x (2/3) and that x 2. ;-).
I don't get 0.148 but 0.1470000000000.
Sorry about that. I forgot to divide by 0.99 and the answer is 0.148. But your error still is the same. Multiply by 3/2 and not by 2/3.
To find the molarity (M) of Cl-, you need to first find the number of moles of Cl- in 990 mL of the aqueous solution.
Step 1: Convert mL to L.
To convert mL to L, divide the volume by 1000:
990 mL ÷ 1000 = 0.990 L
Step 2: Use the balanced equation to find the stoichiometric ratio.
According to the balanced equation, 3 moles of CuCl2 react with 2 moles of Al to produce 2 moles of AlCl3. Therefore, there is a 3:2 stoichiometric ratio between CuCl2 and AlCl3.
Step 3: Calculate the number of moles of Cl-.
Since the molarity of Cl- is required, we need to find the number of moles of Cl-. Since there is no coefficient in front of Cl- in the balanced equation, we assume that the number of moles of Cl- is equal to the number of moles of AlCl3 formed.
Moles of AlCl3 = 0.0490 mol (from the given amount of Al)
Step 4: Calculate the molarity of Cl-.
Molarity (M) is defined as moles of solute divided by liters of solution. Since we have the number of moles of Cl- and the volume in liters, we can calculate the molarity:
Molarity (M) = Moles of Cl- / Volume (L)
Molarity (M) = (0.0490 mol) / (0.990 L)
Now you can calculate the molarity of Cl- by dividing the given number of moles of Cl- by the volume of the solution in liters.