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!!
To solve this problem, you can use the 5-step method to find the concentration of the potassium dichromate solution. Here are the steps to follow:
Step 1: Write the balanced chemical equation for the reaction between tin (II) chloride and potassium dichromate.
2 SnCl2 + K2Cr2O7 + 14 HCl -> 2 SnCl4 + 2 KCl + 2 CrCl3 + 7 H2O
Step 2: Determine the moles of tin (II) chloride used in the reaction.
Given: volume of tin (II) chloride solution = 25.0 mL = 0.0250 L
concentration of tin (II) chloride solution = 0.100 mol/L
Using the equation: moles = volume (L) x concentration (mol/L)
moles of tin (II) chloride = 0.0250 L x 0.100 mol/L = 0.00250 mol
Step 3: Determine the moles of potassium dichromate used in the reaction.
Given: average volume of potassium dichromate solution = 12.7 mL = 0.0127 L
Using the equation: moles = volume (L) x concentration (mol/L)
moles of potassium dichromate = 0.0127 L x concentration (mol/L)
Step 4: Find the ratio between the moles of tin (II) chloride and potassium dichromate.
From the balanced chemical equation in step 1, the ratio is 2:1. This means that 2 moles of tin (II) chloride react with 1 mole of potassium dichromate.
Therefore,
0.00250 mol of tin (II) chloride = 0.00250/2 = 0.00125 mol of potassium dichromate
Step 5: Calculate the concentration of the potassium dichromate solution.
Using the equation: concentration (mol/L) = moles/volume (L)
concentration of potassium dichromate = 0.00125 mol / 0.0127 L
Now, you can calculate the final concentration of the potassium dichromate solution by dividing the moles of potassium dichromate by the volume used.
Finally, convert the concentration to mmol/L by multiplying the result by 1000.
I hope this helps! Good luck with your test.
To solve this question, you can use the 5-step method, also known as the stoichiometry method. Here's how you can apply it to find the concentration of the potassium dichromate solution:
Step 1: Write the balanced equation for the reaction.
In this case, we have tin (II) chloride reacting with potassium dichromate:
SnCl2 + K2Cr2O7 → SnCr2O7 + KCl
Step 2: Determine the stoichiometric ratio between the reactants.
From the balanced equation, we can see that the ratio between SnCl2 and K2Cr2O7 is 1:1.
Step 3: Calculate the number of moles of K2Cr2O7 used.
We are given the volume and concentration of the SnCl2 solution as well as the volume of the K2Cr2O7 solution. We can use these values to calculate the moles of K2Cr2O7 used.
moles of K2Cr2O7 = volume of K2Cr2O7 (L) × concentration of K2Cr2O7 (mol/L)
= 12.7 mL ÷ 1000 mL/L × 0.100 mol/L
= 0.00127 mol
Step 4: Use the stoichiometric ratio to find the moles of SnCl2.
Since the stoichiometric ratio is 1:1, the moles of SnCl2 used will also be 0.00127 mol.
Step 5: Calculate the concentration of the K2Cr2O7 solution.
To find the concentration, divide the moles of K2Cr2O7 used by the volume of K2Cr2O7 solution used:
concentration of K2Cr2O7 = moles of K2Cr2O7 ÷ volume of K2Cr2O7 (L)
= 0.00127 mol ÷ (25.0 mL ÷ 1000 mL/L)
= 50.8 mmol/L
Therefore, the concentration of the potassium dichromate solution is 50.8 mmol/L.