Solutions Concentrations

Which is the correct equation to calculate the number of moles of solute.

• number of moles = concentration x 1000

• number of moles = volume / concentration

• number of moles = concentration / volume

• number of moles = concentration x volume

28g of CaCl₂ was dissolved in 0.4 litres of water.

Calculate the concentration of the solution with the correct units.

• 0.625 g

• 6.25 mol / L

• 70 g/L

• 70 dm³

A student is preparing two solutions, A and B to use in an experiment.

To make solution A he dissolved 40.0g of a substance in 500 cm³ of a solvent.

Calculate the concentration of solution A.

• 0.08 g/L

• 8 g/L

• 0.8 g/L

• 80 g/L

1 dm³ is equal to which.

• 100 cm³

• 1 L

• 1000 g

• 10 cm³

Scientists use what to make up solutions of a particular concentration.

• Concentration Flask

• Aqueous Flask

• Volumetric Flask

• Deionised Flask

How do you decrease the concentration of a solution. Choose 2 options

• add more solvent

• add more solute

• remove solute

• add more water

What term do we use to describe a less concentrated solution?

• Dilute

• Volume

• Aqueous

• Solvent

Which of the solutions above is the most dilute

• A

• C

• E

• They are all the same concentration

Calculate the molarity of a solution made by dissolving: 10.6 g silver nitrate in water and making the volume up to 250 mL in a volumetric flask.

• 170 g/mol

• 0.0624 mol

• 2.49 mol /L

• 0.249 mol/L

Calculate the molarity of a solution made by dissolving: 34.8 g potassium sulfate in water and making the volume up to 100 mL in a volumetric

flask.

• 0.348 mol / L

• 348 mol / L

• 2.45 mol/L

• 2.00 mol / L