someone help pls!!
percentage of ethanol in the "blood" sample on a v/v basis is 0.0143% v/v.
is the "blood" sample analysed over the limit for driving? (legal limit is 80mg alcohol per 100mL blood. assume the density of ethanol is 0.785g/mL and the density of blood is 1.0g/mL).
Appreciated if you could show me the calculation. thanks!!
0.0143% v/v means 0.0143 mL/100 mL.
mass = volume x density = 0.0143 mL x 0.785 g/mL = 0.011 g/100 mL = 11 mg/100 mL. Compare to 80 mg/100 mL.
thank you!!
To determine if the "blood" sample is over the legal limit for driving, we need to convert the percentage of ethanol from a v/v basis to mg/100mL.
Here's how you can calculate it step by step:
Step 1: Convert the percentage of ethanol to a decimal:
0.0143% = 0.0143/100 = 0.000143
Step 2: Multiply the decimal value by the density of blood to obtain the concentration in g/mL:
0.000143 * 1.0 g/mL = 0.000143 g/mL
Step 3: Convert the concentration from g/mL to mg/100mL:
0.000143 g/mL * 1000 mg/g = 0.143 mg/100mL
Step 4: Compare the calculated concentration to the legal limit:
The legal limit is 80 mg alcohol per 100 mL blood, so if the calculated concentration is greater than 80 mg/100mL, then it exceeds the limit.
In this case, the concentration of ethanol in the blood sample is 0.143 mg/100mL, which is less than the legal limit of 80 mg/100mL. Therefore, the blood sample is not over the limit for driving.