Core Practical: Determining Density Flashcards

All 5 cards in this deck

What are the steps to determine the density of a regular solid such as a cuboid?

e.g. a block $2$ cm $\times$ $3$ cm $\times$ $5$ cm of mass $60$ g

1. Measure mass on a balance: $60$ g
2. Measure the sides with a ruler and calculate volume: $2 \times 3 \times 5 = 30$ cm$^3$
3. Density $=$ mass $\div$ volume $= 60 \div 30 = 2$ g/cm$^3$

What are the steps to determine the density of an irregular solid using water displacement?

e.g. a stone of mass $60$ g

1. Measure the mass on a balance: $60$ g
2. Lower it into a measuring cylinder (or displacement can) of water and find the volume of water displaced: $20$ cm$^3$
3. Density $=$ mass $\div$ volume $= 60 \div 20 = 3$ g/cm$^3$

What are the steps to determine the density of a liquid using a balance and a measuring cylinder?

e.g. empty cylinder $50$ g; with $20$ cm$^3$ of liquid $66$ g

1. Find the mass of the liquid by subtracting: $66 - 50 = 16$ g
2. Read the volume from the cylinder: $20$ cm$^3$
3. Density $=$ mass $\div$ volume $= 16 \div 20 = 0.8$ g/cm$^3$

True or false? When finding the density of a liquid, the balance reading of the liquid in the measuring cylinder can be used as the mass of the liquid.

False. The mass of the empty measuring cylinder must be subtracted first.

How should a measuring cylinder be read to avoid a parallax error?

With the eye level with the bottom of the meniscus.