In my bio lab we are creating serial disk dilutions (100mg, 300mg, 500mg) from a plant extraction sample.
Wood sample #1 (7mL of hexane)
Hexane 0.6651g
so .6651g of the plant was dissolved in 7mL of hexane. Then I did dilution calculations
so 0.6551g/7 mL = 0.095g/ml
so I assumed 10mL of 100mg/L
10ml x .1g/mL= 1 g
vmL x .095g/mL= 1 g
vmL= 10.52 mL
so I assumed 10mL of 300mg/mL
10ml x .3g/ml= 3g
vmL x .095g/mL= 3g
VmL= 31.57 mL
so I assumed 10mL of 500mg/mL
10 mL x .5g/mL =5 g
10mL x .095g/mL = 5g
VmL= 52.6 mL
Please let me know where I am going wrong if you a problem. I appreciate the help. Thank you.
It seems like you are trying to calculate the volume of the plant extraction sample needed to create different concentrations (100mg/mL, 300mg/mL, 500mg/mL) through serial dilutions. However, there are some errors in your calculations.
Let's go through each dilution step and correct the mistakes:
1. Wood sample #1 (7mL of hexane) - You mentioned that 0.6651g of the plant was dissolved in 7mL of hexane. To calculate the concentration, you divided 0.6651g by 7mL, which is correct. This gives you a concentration of 0.095g/mL.
2. Dilution 1 - You assumed 10mL of a 100mg/mL concentration. To calculate the volume of the plant extraction sample needed, you multiplied the desired concentration (100mg/mL) by the volume (10mL). However, you should divide the desired concentration (1g) by the concentration of the plant extraction (0.095g/mL). So the correct calculation would be:
Desired concentration (1g) / Concentration of plant extraction (0.095g/mL) = 10.53 mL
Therefore, you would need 10.53 mL of the plant extraction sample to create a 100mg/mL concentration.
3. Dilution 2 - You assumed 10mL of a 300mg/mL concentration. Similarly, you need to divide the desired concentration (3g) by the concentration of the plant extraction (0.095g/mL). The correct calculation would be:
Desired concentration (3g) / Concentration of plant extraction (0.095g/mL) = 31.58 mL
Therefore, you would need 31.58 mL of the 100mg/mL solution to create a 300mg/mL concentration.
4. Dilution 3 - You assumed 10mL of a 500mg/mL concentration. Again, divide the desired concentration (5g) by the concentration of the plant extraction (0.095g/mL). The correct calculation would be:
Desired concentration (5g) / Concentration of plant extraction (0.095g/mL) = 52.63 mL
Therefore, you would need 52.63 mL of the 300mg/mL solution to create a 500mg/mL concentration.
To summarize, the corrected calculations for the volume of the plant extraction sample needed for each dilution would be:
1. 10.53 mL for a 100mg/mL concentration
2. 31.58 mL for a 300mg/mL concentration
3. 52.63 mL for a 500mg/mL concentration
I hope this helps clarify the correct calculations for your serial dilutions in the bio lab. Let me know if you have any further questions!