How many grams of solid magnesium chloride, MgCl₂, are needed to make 250 mL of 0.50 M solution? A)9.5 g B)48 g C)12 g D)125 g E)4.8 g

Question

Quizplus · Accepted Answer

To calculate the amount (in grams) of magnesium chloride needed, we can use the formula:

mass = molarity x volume x molar mass

where molarity is given as 0.50 M, volume is 250 mL, and molar mass of MgCl2 is (24.31 + 2x35.45) = 95.21 g/mol.

Substituting the values, we get:

mass = 0.50 x 0.25 x 95.21 
mass = 11.90 g

Therefore, we need 11.90 g of magnesium chloride. However, since the answer choices only have one option in grams, we choose the one closest to 11.90 g, which is option C (12 g).

How Many Grams of Solid Magnesium Chloride, MgCl2, Are Needed

How Many Grams of Solid Magnesium Chloride, MgCl₂, Are Needed