Concentrations of Solutions Flashcards

All 6 cards in this deck

What is the formula for the concentration of a solution in g/dm$^3$?

concentration = mass of solute (g) ÷ volume of solution (dm$^3$)

How many cm$^3$ are there in 1 dm$^3$?

1000 cm$^3$.

What are the steps to calculate a concentration in g/dm$^3$ when the volume is given in cm$^3$?
e.g. 5 g of solute in 250 cm$^3$ of solution

1. Convert the volume to dm$^3$: $250 \div 1000 = 0.25$ dm$^3$
2. concentration = mass ÷ volume = $5 \div 0.25$ = 20 g/dm$^3$

What are the steps to calculate the mass of solute in a given volume of solution of known concentration?
e.g. 500 cm$^3$ of a 20 g/dm$^3$ solution

1. Convert the volume to dm$^3$: $500 \div 1000 = 0.5$ dm$^3$
2. mass = concentration $\times$ volume = $20 \times 0.5$ = 10 g

True or false? Adding more water to a solution, keeping the mass of solute the same, decreases its concentration.

True. A larger volume of solution for the same mass of solute means a lower concentration.

How does concentration change if the mass of solute dissolved is increased but the volume of solution stays the same?

The concentration increases, in proportion to the mass of solute.