You have a sample – sample 1 - that has a concentration (✗) particles. From this you take 1 mL and add it to 99 mL water to create sample 2. You then take 1 mL of sample 2 and place it in 99 mL of water to create sample 3. And lastly, you take 1 mL of sample 3 and add it to 9 mL of water to create sample 4. What is the final dilution factor in sample 4? You may use drawings if it helps you understand and explain, though not necessary.

The table below summarizes the results for Sudan IV test. Which solvent the lipid samples are homogeneous? PUT A CHECK   Hexane Ethyl Acetate Water Methanol A         B         C         Which solvent the lipid samples are heterogeneous? PUT A CHECK   Hexane Ethyl Acetate Water Methanol A         B         C             What is the nature of the lipid samples?* A. Polar B. Nonpolar

If you diluted 200 uL of your culture into 1800 uL of water what is your dilution factor? (Show your work)

Is there a difference between pH measurements using the pH meter and the pH paper? Compare the initial pH and the final pH of each sample. What was the most effective buffer? What was the least effective?  Solución pH inicial pH final Diferencia water 7.45 2.48   0.1 M NaCl 7.28 2.03   milk 6.78 6.45   buffer de fosfato 8.76 7.78     **** Calculate the difference (subtract) the initial pH - final pH values ​​to identify the effectiveness of each solution as a buffer. Values ​​with little difference mean that a less drastic change occurred and are therefore more effective. On the contrary, values ​​by much difference reflect drastic changes in pH and are less effective. What do buffers do and why are they important in biological systems?

Propose a serial dilution that would give a dilution of 1/153 000 000. Each tube in your dilution series must have a volume of 50 ml or less.

You are testing a sample of water from a swimming pool. You count a plate made from a 1 mL transfer of a 10-1 dilution and it has 38 colonies on it. Calculate the number of CFu/mL for this plate.

You have a culture of cells at 3.5 x 108 cells/ml and you want to prepare a fresh 5 ml culture with a starting density of 1 x 104 cells/ml. What volume of the old culture do you add to the new 5 ml culture?

A 25.00 mL sample of 0.320 M LIOH is titrated with 0.750 M HNO3 at 25 °C. Calculate the initial pH before any titrant is added. pH = Calculate the pH of the solution after 5.00 mL of the titrant is added. pH =

Using 10 μL of a patient's serum, how much diluent would be needed to create a 1:10 dilution? ______ μL

Explain the color changes observed throughout the peroxide value of oil experiment. Materials:1. Old and fresh oil samples2. Distilled water3. Acetic acid/chloroform solution4. Saturated potassium iodide solution5. Sodium thiosulphate (0.01M)6. 1% Starch indicator: dissolve 1g of starch in 10 ml of water and then add 90 ml of hotwater to it