Question

What volume of a 2% erythromycin solution can be made from 15 gm of erythromycin powder?

Answer 1

The concentration of volume of solution can be expressed in many ways for example: mass percent, volume percent, mass-by-volume percent, etc.

The formula for mass-by-volume percent is:

mass-by-volume percent = $\frac{g of solute}{100 mL of solution}$

2% erythromycin solution means 2 g of erythromycin in 100 mL.

Consider, for 15 g the volume be X mL.

So,

$\frac{X mL}{15 g} = \frac{100 mL}{2 g}$

$X= \frac{100\times 15}{2}$

$X= 750 mL$

Hence, the volume is $750 mL$.

Answer 2

Let the volume of erythromycin solution be x

And given amount of  erythromycin solution is 15 g

then  

2% of x = 15 g

That is  

$\frac{2}{100} \times x = 15$

2x = 1500

x = 750

So, x found to be 750.

So, the volume of erythromycin solution found to be 750 mL that is 750 mL of a 2% erythromycin solution can be made from 15 gm of erythromycin powder.