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BioTech Mathematical Examples

1

Write The Following Percents as a Fraction and Decimal:

23%

4.6%

190%

.74%

Solve the Following Percentage Problems:

10% of 35 is what number?

1.2 is 12% of what number?

What percent of 80 is 88?

17 is what percent of 50?

How far is a 10km race in miles?

A car is going 55 mph. How fast is it moving in km per hour?

Bacteria are growing in a flask. The growth medium for the bacteria requires 5g fo glucose per liter. A

technician has prepared some medium and added 0.24 pounds of glucose to 25 liters. Did the technician

make the broth correctly?

An assay is performed in which the correct answer is known to be 200.8 mg. The assay gives a value of

200.1. What is the percent error?

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BioTech Mathematical Examples

2

How much solute is required to make 500 ml of a 0.25 M solution of NaCl?

How would you prepare 10 Liters of 0.3 M

KH PO 2 4

?

Convert 20% (w/v) NaCl to molarity. The FW of NaCl is 58.44.

How would you make 250 mL of a 1⁄4 dilution of food coloring?

A stock solution initially has a concentration of 20 mg if solute per liter. A diluted solution is prepared by

removing 1 mL of stock solution and adding 14 mL of water.

a) What is the concentration of solute in the diluted solution?

b) How much solute is present in 1 mL of the diluted solution?

A stock solution has a total volume of 100 mL. It is diluted by removing 1 mL of stock solution and

adding 24 mL of water. The concentration of solute in the dilution is 1.5g/L.

a) What is the concentration of solute in the solution?

b) How much solute is present in the total 100 mL if stock?