Question

Jordan is working with a 50% stock concentration of Windex. She decides to add 500 µL of bacteria to a tube containing 1 mL of nutrient broth and then adds 500µL of the Windex stock to the tube as well. What is the unknown concentration of the tube?

Answer 1

33% is the unknown concentration of the tube.

Explanation:

Concentration of stock of windex = 50%

concentration of bacteria = 500 microliter

nutrient broth = 1000 micro litre +500 microlitre of windex

concentration of bacteria is the volume of bacteria present in nutrient broth culture.

total volume in the tube is 1000

50% is the concentration of tube of bacteria and broth before adding windex.

After adding windex of 50 % concentration and the volume is 500 microliter which is only 250 microliter of windex rest is water.

33% is the concentration of the tube, which means it has 33% of bacteria in 1500 ml of solution.