Question

A prescription calls for the following: Sodium citrate 5 g Tartar Emetic 0.015 g Cherry syrup ad 120 mL Using a balance with a sensitivity of 4 mg, an acceptable weighing error of 5% and cherry syrup as the solvent for tartar emetic, how could you obtain the correct quantity of tartar emetic to fill the prescription?

Answer 1

Answer:

measure the volume of cherry syrup solution with Tartar Emetic = 22.5 mL

Hence, the correct quantity of tartar emetic to fill the prescription will be obtained

Step-by-step explanation:

Given:

Mass of Sodium citrate = 5 g

Mass of Tartar Emetic = 0.015 g = 15 mg

Volume of Cherry syrup ad 120 mL = 120 mL

sensitivity = 4 mg

Error = 5%

Now,

The smallest weight that can be measured = $\frac{\textup{Sensitivity}}{\textup{Error}}\times100$

or

The smallest weight that can be measured =  $\frac{\textup{4}}{\textup{5}}\times100$  = 80 mg

Now,

80 mg is dissolved in 120 mL of Cherry syrup according to prescription

( Thus,

1 mg is dissolved in $\frac{120}{80}\ mL$  of Cherry syrup according to prescription )

so to measure 15 mg of Tartar Emetic, measure the volume of cherry syrup

=   $15\times\frac{120}{80}\ mL$

= 22.5 mL

Hence, the correct quantity of tartar emetic to fill the prescription will be obtained