BACE - Biotechnician Assistant Credentialing Solution Preparation and Calculations Questions and Answers

Question 1

A technician needs to prepare 500 mL of a 0.5 M Tris-HCl buffer. The formula weight of Tris is 121.14 g/mol. How many grams of Tris should be weighed out?

Accepted Answer

30.29 g

Answer

121.14 g

Answer

60.57 g

Answer

500 g

Question 2

A biotechnician is asked to make a 1:10 dilution of a concentrated stock solution to a final volume of 100 mL. Which of the following correctly describes the procedure?

Accepted Answer

Mix 10 mL of stock solution with 90 mL of diluent.

Answer

Mix 1 mL of stock solution with 99 mL of diluent.

Answer

Mix 10 mL of stock solution with 100 mL of diluent.

Answer

Mix 90 mL of stock solution with 10 mL of diluent.

Question 3

A lab protocol requires the preparation of a 2% (w/v) agarose gel solution in a total volume of 150 mL. How much agarose powder is needed?

Accepted Answer

3.0 g

Answer

2.0 g

Answer

0.3 g

Answer

30.0 g

Question 4

You need to prepare 250 mL of a 1X working solution from a 20X stock solution. How much of the 20X stock solution is required?

Accepted Answer

12.5 mL

Answer

10.0 mL

Answer

20.0 mL

Answer

25.0 mL

Question 5

Which of the following is the most critical final step before finalizing the volume of a buffer solution prepared from solid components?

Accepted Answer

Adjusting the pH to the desired value.

Answer

Heating the solution to ensure all solutes are dissolved.

Answer

Allowing the solution to sit for at least one hour.

Answer

Vortexing the solution vigorously for five minutes.

Question 6

A technician prepares a solution by dissolving 58.44 grams of NaCl (Formula Weight = 58.44 g/mol) in enough water to make a final volume of 1.0 L. What is the molarity (M) of this solution?

Accepted Answer

1.0 M

Answer

0.1 M

Answer

0.5 M

Answer

2.0 M

A technician needs to prepare 500 mL of a 0.5 M Tris-HCl buffer.The formula weight of Tris is 121.14 g/mol.How many grams of Tris should be weighed out?

A technician needs to prepare 500 mL of a 0.5 M Tris-HCl buffer.
The formula weight of Tris is 121.14 g/mol.
How many grams of Tris should be weighed out?