A doctor orders 4.0 mL of phenobarbital elixir. If the phenobarbital is available as 30 mg per 7.5 mL, how many milligrams is given to the patient? Express your answer to two and include the appropriate units
To find the number of milligrams given to the patient, we need to find the amount of phenobarbital in 4.0 mL of the elixir.
First, let's find the concentration of phenobarbital in the elixir:
30 mg per 7.5 mL
To find the concentration of phenobarbital per mL, we divide both the numerator and denominator by 7.5:
30 mg / 7.5 mL = 4 mg / 1 mL
Therefore, the concentration of phenobarbital in the elixir is 4 mg/mL.
Next, we multiply the concentration by the volume of the elixir given to the patient:
4 mg/mL * 4.0 mL = 16 mg
So, 16 milligrams is given to the patient.
To find out how many milligrams of phenobarbital are given to the patient, we can use a proportion.
The given concentration is 30 mg per 7.5 mL. We need to find the amount in 4.0 mL.
Let "x" represent the number of milligrams given to the patient.
Using the proportion:
30 mg / 7.5 mL = x mg / 4.0 mL
Now we can cross-multiply:
7.5 mL * x mg = 30 mg * 4.0 mL
7.5x = 120
Next, divide both sides of the equation by 7.5 to solve for x:
x = 120 / 7.5
x ≈ 16
Therefore, approximately 16 milligrams of phenobarbital are given to the patient.
To find the number of milligrams of phenobarbital given to the patient, we need to convert the given amount of elixir (4.0 mL) to milligrams using the given concentration (30 mg per 7.5 mL).
First, let's calculate the concentration of phenobarbital in terms of milligrams per milliliter (mg/mL):
Concentration = (30 mg) / (7.5 mL) = 4 mg/mL
Now, we can find the number of milligrams given to the patient by multiplying the volume of the elixir (4.0 mL) with the concentration:
Milligrams = (4.0 mL) * (4 mg/mL) = 16 mg
Therefore, the patient is given 16 milligrams of phenobarbital.