Question

Prelab 9: Due at the start of Lab 9

Name:________________________   Lab day________

Show all work, even simple addition and include units and sig figs where applicable.

1. To make solutions for the Beer's Law graph, you are provided with a 49.9 ppm Allura Red solution. You pipet 10.00 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 Allura Red concentration of the new solution you've made? This is Allura Red Dilution 1.

V _final =

C _final =

2. If you pipet 10.00 mL of the solution you made in Question #1 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 #1 to calculate this answer to avoid rounding errors. Your final answer will be reported to the correct number of sf. This is Allura Red Dilution 2.

V _final =

C _final =

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 will be reported to the correct number of sf. This is Allura Red Dilution 3.

V _final =

C _final =

4. To make solutions for the Density of KCl graph, you are provided with a 12.0% KCl 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 KCl concentration of the new solution you've made? This is KCl 2 solution.

V _final =

C _final =

5. To make solutions for the Density of KCl graph, you are provided with a 12.0% KCl 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 KCl concentration of the new solution you've made? This is KCl 3 solution.

V _final =

C _final =

6. To make solutions for the Density of KCl graph, you are provided with a 12.0% KCl solution. You pipet 10.00 mL of this solution into a test tube and then you pipet 30.00 mL of deionized water into the same tube. After stirring, what is the KCl concentration of the new solution you've made? This is KCl 4 solution.

V _final =

C _final =

7. Using the equation of the line in the graph below, calculate the concentration of Allura Red (in ppm) of the Buckeye-ade sample which has an absorbance of 0.415 a.u.

y= 0.0494x

R^2= 0.9861

Answer 1