Question

Ketamine, Sometimes used as an adjuvant to general Anesthesia, it’s available as a 10.0% (w/v) solution. Calculate the volume of the solution that contains 30. mg of ketamine. Be sure your answer has a unit symbol and is running to the CORRECT NUMBER OF SiGNIFICANT DIGITS.

Answer 1

1) List known values

Ketamine solution: 10.0% (w/v) solution

Mass of Ketamine: 30mg

2) List unknown values

The volume of solution.

3) Set the equation

`mass\text{ percent=}\frac{\text{grams of solute}}{\text{milliliters of solution}}\cdot100`

4) Convert mg to g.

`\text{gramsofsolute}=30mg\cdot(1g)/(1000mg)=0.03g\text{ of ketamine}`

5) Plug in known quantities and solve for volume.

`10.0=\frac{0.03g\text{ of ketamine}}{\text{volume of solution (mL)}}\cdot100`

Rearrange algebraically

`\text{Volume of solution (mL)=}\frac{0.03g\text{ of ketamine}}{10}\cdot100=\text{ 0.}3mL`

The volume that contains 30 mg of ketamine is 0.3mL

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