A chemist adds of a magnesium fluoride solution to a reaction flask. Calculate the mass in micrograms of magnesium fluoride the chemist has added to the flask. Round your answer to significant digits.

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.

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