Question

Convert 2.0 M of Phenobarbital sodium (MW: 254 g/mole) solution in water into % w/v and ratio strengths.

Answer 1

Answer:

The concentration is 50,8 % w/v and radio strengths = 1,96.

Explanation:

Phenobarbital sodium is a medication that could treat insomnia, for example.

2,0 M of Phenobarbital sodium means 2 moles in 1L.

The concentration units in this case are %w/v that means 1g in 100 mL and ratio strengths that means  1g in r mL. Thus, 2 moles must be converted in grams with molar weight -254 g/mole- and liters to mililiters -1 L are 1000mL-. So:

2 moles × $\frac{254 g}{1 mole}$= 508 g of Phenobarbital sodium.

1 L ×$\frac{1000 mL}{ 1 L}$ = 1000 mL of solution

Thus, % w/v is:

$\frac{508 g}{1000 mL}$ × 100 = 50,8 % w/v

And radio strengths:

$\frac{1000 mL}{508 g}$  = 1,96. Thus, you have 1 g in 1,96 mL

I hope it helps!