Mass Concentration g/L

In the picture

1. 1A balance with a small dish of blue crystals: the mass of solid is measured before it dissolves.
2. 2A volumetric flask filled to its single ring mark with deep blue liquid: the total volume of the solution is set accurately.
3. 3A pipette between two flasks: a measured volume of stock solution is transferred.
4. 4A second flask holding a paler blue liquid: the diluted solution has a lower concentration.

Examples

• A saline drip bag labelled 9 g/L contains 9 grams of salt in each litre.
• A sugar syrup for drinks at 100 g/L contains 100 grams of sugar in each litre.

Quiz: Mass Concentration g/L (Age 15)

1. 1

   What does mass concentration in g/L express?

   • grams of solvent per litre of solution
   • grams of solution per litre of solvent
   • grams of solute per litre of solution
2. 2

   What happens when a stock solution is diluted with solvent?

   • The volume increases and the concentration increases, while the mass of solute also increases.
   • The volume increases and the concentration decreases, while the mass of solute stays the same.
   • The volume decreases and the concentration increases, while the mass of solute stays the same.
3. 3

   Which methods can prepare an aqueous solution of known mass concentration?

   • Boiling the solution until only crystals remain
   • Adding solute without measuring until no more dissolves
   • Dissolving a weighed solid, or diluting a stock solution

The answers, each with its explanation, are in the app. This lesson has left the free week, so its quiz is part of the subscription.