The given question is incomplete, the complete question is:

A chemist adds 35.0mL of a 6.19 * 10^−4/mmol magnesium fluorideMgF2 solution to a reaction flask. Calculate the mass in micrograms of magnesium fluoride the chemist has added to the flask. Round your answer to

3 significant digits.

Answer:

The correct answer is 1.35 microgram.

Explanation:

Based on the given information,

The volume of magnesium fluoride given is 35 ml, and the concentration of magnesium fluoride is 6.19 × 10⁻⁴ mmol/L.

Now the moles of MgF₂ can be determined by using the formula,

Moles = Concentration × Volume

Moles of MgF₂ = Concentration of MgF₂ × Volume of MgF₂

= 6.19 × 10⁻⁴ mmol/L × 35 ml × L/1000 ml

= 217 × 10⁻⁷ mmol

The molecular mass of magnesium fluoride is 62.3 gram per mole

Thus, the mass of MgF₂ is,

= 217 × 10⁻⁷ mmol × 62.3 g/mol

= 13500 × 10⁻⁷ mg

= 1.35 microgram