25.0mL of an acidic 0.100 mol/L tin (II) chloride solution required an average volume of 12.7 mL of potassium dichromate solution for a complete reaction. The amount of concentration of the potassium dichromate solution is _______ mmol/L

How do you go about solving this? I think that the 5 step method is involved in finding a solution :/ Please help!! My test is tomorrow :( thanksss!!

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To find the concentration of the potassium dichromate solution (in mmol/L), you can follow these steps:

Step 1: Write the balanced chemical equation for the reaction between tin (II) chloride and potassium dichromate. Assume that the reaction is taking place in acidic conditions. The balanced equation is as follows:
SnCl2(aq) + K2Cr2O7(aq) → SnCl4(aq) + CrCl3(aq) + KCl(aq)

Step 2: Use stoichiometry to determine the mole ratio between tin (II) chloride and potassium dichromate from the balanced equation. From the equation, you can see that the mole ratio is 1:1. Therefore, the amount of tin (II) chloride reacted is also 0.100 mol.

Step 3: Convert the volume of tin (II) chloride solution to moles using the equation:
moles = concentration × volume (in L)
moles of tin (II) chloride = 0.100 mol/L × 0.025 L = 0.0025 mol

Step 4: Use the mole ratio from step 2 to determine the moles of potassium dichromate that reacted. Since the mole ratio is 1:1, the moles of potassium dichromate is also 0.0025 mol.

Step 5: Convert the moles of potassium dichromate to concentration using the equation:
concentration = moles / volume (in L)
concentration of potassium dichromate = 0.0025 mol / 0.0127 L = 0.1969 mol/L

Therefore, the concentration of the potassium dichromate solution is 196.9 mmol/L.

To find the concentration of the potassium dichromate solution in mmol/L, you can use the following five-step method:

Step 1: Write down the balanced chemical equation for the reaction between tin(II) chloride and potassium dichromate. This will help you determine the stoichiometry of the reaction.

Step 2: Calculate the number of moles of tin(II) chloride used in the reaction. To do this, multiply the volume of the tin(II) chloride solution (25.0 mL) by its concentration (0.100 mol/L).

Step 3: Determine the mole ratio between tin(II) chloride and potassium dichromate from the balanced equation.

Step 4: Calculate the number of moles of potassium dichromate required for the reaction. Multiply the number of moles of tin(II) chloride from step 2 by the mole ratio from step 3.

Step 5: Calculate the concentration of the potassium dichromate solution. Divide the number of moles of potassium dichromate from step 4 by the volume of the potassium dichromate solution (12.7 mL), and express the result in mmol/L.

Now, let's go through the steps using the given information:

Step 1: The balanced chemical equation for the reaction between tin(II) chloride (SnCl2) and potassium dichromate (K2Cr2O7) is:

3 SnCl2(aq) + 2 K2Cr2O7(aq) → 3 SnCl4(aq) + Cr2O3(s) + 4 KCl(aq)

Step 2: The number of moles of tin(II) chloride used in the reaction can be calculated as follows:

moles of SnCl2 = volume of SnCl2 solution (in L) × concentration of SnCl2 solution (in mol/L)
= 25.0 mL ÷ 1000 mL/L × 0.100 mol/L

Step 3: The mole ratio between tin(II) chloride and potassium dichromate from the balanced equation is 3:2.

Step 4: The number of moles of potassium dichromate required for the reaction can be calculated as follows:

moles of K2Cr2O7 = moles of SnCl2 × (2 moles of K2Cr2O7 / 3 moles of SnCl2)

Step 5: The concentration of the potassium dichromate solution can be calculated as follows:

concentration of K2Cr2O7 (in mmol/L) = moles of K2Cr2O7 ÷ volume of K2Cr2O7 solution (in L) × 1000

By following these steps and plugging in the given values, you should be able to find the concentration of the potassium dichromate solution in mmol/L. Good luck with your test!