3.4 Using concentrations of solutions in mol/dm³

• What is measured in grams (g)?

  Mass
• What is the formula for molar concentration?

  Concentration = moles/volume
• The formula for molar concentration is $concentration =$$\frac{number\ of\ moles}{volume\ (dm^{3})}$, where volume is measured in dm³
• What is the SI unit for the amount of substance?

  Mole
• Molar concentration indicates the number of moles of solute in one liter of solution.

  True
• A mole contains the same number of particles as there are atoms in 12 grams of carbon-12.


  True
• Molar concentration is expressed in moles per cubic decimeter (mol/dm³).

  True
• What is the relationship between moles, mass, and number of particles?

  Moles relate to mass and particles
• How many grams of carbon-12 are used to define a mole?

  12 grams
• The mole represents a specific number of particles, regardless of the substance.


  True
• Molar concentration is expressed in units of moles per cubic decimeter
• What does the molar concentration formula measure?

  Amount of solute
• A solution containing 0.5 moles of NaCl in 2 dm³ of water has a concentration of 0.25 mol/dm³
• A 1.5 dm³ solution with a molar concentration of 0.2 mol/dm³ contains 0.3 moles of solute.
• The formula for molar concentration is concentration
• To calculate the volume of a solution, you divide the number of moles by the molar concentration.


  True
• The mole is the unit for the amount of substance.


  True
• Match the quantity with its definition:

  Moles ↔️ Unit for amount of substance

  Mass ↔️ Amount of substance in grams

  Number of particles ↔️ Atoms, molecules, or ions
• If 0.5 moles of NaCl are dissolved in 2 dm³ of solution, the molar concentration is 0.25 mol/dm³.


  True
• The concentration of a solution is defined as the number of moles of solute per volume of solution.
• To calculate the number of moles, you multiply the concentration by the volume.
• The formula to calculate moles from molar concentration and volume is moles = concentration × volume.


  True
• Match the quantity with its unit:

  Volume ↔️ dm³

  Moles ↔️ mol

  Concentration ↔️ mol/dm³
• A molar concentration of 0.25 mol/dm³ is equivalent to 250,000 ppm.
• To convert mol/dm³ to g/dm³, you multiply by the molar mass of the substance.


  True
• A solution with 14.61 g/dm³ of NaCl is equivalent to 250,000 ppm.

  True
• What is the molar mass of NaCl?

  58.44 g/mol
• To dilute the HCl solution to 0.1 mol/dm³, 400 cm³ of water should be added.
• The volume in the molar concentration formula must be in cubic decimeters (dm³).


  True
• The concentration of a solution is always expressed in moles per cubic meter.

  False
• The number of moles in a solution can only be calculated if the volume is in liters.

  False
• What is the formula for calculating the number of moles from molar concentration and volume?

  $n =$$C \times V$
• What is the formula for calculating the volume of a solution given the number of moles and concentration?

  $V =$$\frac{n}{C}$
• The mole is defined as the amount of substance that contains the same number of particles as there are atoms in 12 grams of carbon-12
• What is molar concentration also known as?

  Molarity
• What do you divide the number of moles by to calculate molar concentration?

  Volume in dm³
• Molar concentration is also known as molarity.


  True
• What is the number of moles in a 2.5 dm³ solution with a concentration of 0.3 mol/dm³?

  0.75 mol
• The formula to calculate volume from moles and concentration is $volume =$$\frac{moles}{concentration}$, where the volume is in dm³.
• To convert molar concentration from mol/dm³ to g/dm³, you multiply by the molar mass.