Answer to Question #113004 in General Chemistry for Mikayla Walker

Question

Milk of magnesia, Mg(OH)2, is commonly used as an antacid and is available in both tablet and liquid forms.
c) You have been supplied with a concentrated oral suspension of milk of magnesia that has a concentration of 2400 mg/10mL. Explain how you would prepare 200.0 mL of a

600 mg/10mL solution of the antacid for use for a child.

Answer 1

Let V(ml) be the volume of initial suspension. Then V will contain V/10*2400 = 240*V mg of milk of magnesia. We need 200/10*600 = 12000 mg of milk of magnesia.

240*V = 12000

V = 50 (ml)

So to prepare desired solution we need to take a 200 ml volumetric flask, add 50 ml of concentrated suspension, and add 150 ml (to the mark) of water.