Using molarity to find solute moles and solution volume Problem PageQuestion

Question

A chemist adds 1.10L of a 0.74M aluminum chloride AlCl3 solution to a reaction flask. Calculate the millimoles of aluminum chloride the chemist has added to the flask. Be sure your answer has the correct number of significant digits.

Answer 1

First we’ll find the moles added.

1.10 L x 0.74 mol / L = 0.814 moles

Next we’ll convert this to millimoles

0.814 moles x 1000 moles/mole = 814 mmoles

Finally we’ll round to 2 significant digits based on 0.74 having only 2:

810 millimoles