Question

3. If you pipet 10.00 mL of the solution you made in Question #2 into a test tube and then you pipet 10.00 mL of deionized water into the same tube. After stirring, what is the Allura Red concentration of the new solution you've made? Hint: use at least 2 extra significant figures from your answer to question #2 to calculate this answer to avoid rounding errors. Your final answer willl be reported to the correct number of sf. This is Allura Red Dilution 3. V inal C inal 4. To make solutions for the Density of KCI graph, you are provided with a 12.0% KCI solution. You pipet 30.00 mL of this solution into a test tube and then you pipet 10.00 mL of deionized water into the same tube. After stirring, what is the KCI concentration of the new solution you've made? This is KCI 2 solution. V final C final= 5. To make solutions for the Density of KCI graph, you are provided with a 12.0% KCI solution. You pipet 20.00 mL of this solution into a test tube and then you pipet 20.00 mL of deionized water into the same tube. After stirring, what is the KCI concentration of the new solution you've made? This is KCI 3 solution. V final C final= Page 2 of 3

Answer 1

All of these can be solved using the dilution formula, which states that:

$V_{1}\cdot C_{1}=V_{2}\cdot C_{2}$

Where the subscripts 1 and 2 make reference to values before and after dilution, respectively.

3. I don't know the concentration of the solution you prepared in problem 2, but I can help you at least a little. Your initial volume (V₁) is 10.00 mL of that solution, and you'll add 10.00 mL of water, which means that your final volume (V₂) is the sum of bot: 20.00 mL, so your concentration will be:

$C_{2}=\frac{V_{1}\cdot C_{1}}{V_{2}}=\frac{10.00mL\cdot C_{1}}{20.00mL}=\frac{C_{1}}{2}$

It will be half the concentration of problem 2.

4. Now your are taking 30.00 mL (V₁) of a 12.0% (C₁) solution, and adding 10.00 mL of water, making a total value (V₂) of 40.00 mL, so your final concentration is:

$C_{2}=\frac{V_{1}\cdot C_{1}}{V_{2}}=\frac{30.00mL\cdot 12.0}{40.00mL}=9.00$

9.00%

5. You are now taking 20.00 mL (V₁) of the 12.0% (C₁) solution, and adding an extra 20.00 mL, making a final volume (V₂= of 40.00 mL. Your concentration after dilution is then:

$C_{2}=\frac{V_{1}\cdot C_{1}}{V_{2}}=\frac{20.00mL\cdot 12.0}{40.00mL}=6.00$

6.00%.