Concentration Flashcards

All 6 cards in this deck

What is the formula for the concentration of a solution in $\mathrm{g\ dm^{-3}}$?

concentration $= \dfrac{\text{mass of solute (g)}}{\text{volume of solution (dm}^3)}$

How do you convert a volume in $\mathrm{cm^3}$ to $\mathrm{dm^3}$?

e.g. $250\ \mathrm{cm^3}$

Divide by 1000.
$250 \div 1000 = 0.25\ \mathrm{dm^3}$

What are the steps to calculate the concentration of a solution in $\mathrm{g\ dm^{-3}}$?

e.g. 9 g of solute in $200\ \mathrm{cm^3}$ of solution

1. Convert the volume to $\mathrm{dm^3}$: $200 \div 1000 = 0.2$
2. Divide mass by volume: $9 \div 0.2 = 45\ \mathrm{g\ dm^{-3}}$

How do you find the mass of solute in a solution from its concentration in $\mathrm{g\ dm^{-3}}$?

e.g. $50\ \mathrm{g\ dm^{-3}}$ in $500\ \mathrm{cm^3}$

Mass $=$ concentration $\times$ volume in $\mathrm{dm^3}$.
$50 \times 0.5 = 25$ g

True or false? $1\ \mathrm{dm^3}$ is the same volume as $1000\ \mathrm{cm^3}$.

True. $1\ \mathrm{dm^3} = 1000\ \mathrm{cm^3} = 1$ litre.

True or false? Dividing a mass in grams by a volume in $\mathrm{cm^3}$ gives the concentration in $\mathrm{g\ dm^{-3}}$.

False. You must then multiply by 1000, or convert the volume to $\mathrm{dm^3}$ first.