Density
Which of the following is the correct definition of density?
A rectangular metal block has dimensions 5.0 cm × 4.0 cm × 2.0 cm and a mass of 320 g. Calculate the density of the metal in g cm⁻³.
A student wishes to determine the density of olive oil. She places an empty measuring cylinder on a balance and records a mass of 62 g. After pouring olive oil into the cylinder, the balance reads 130 g and the volume reading is 75 cm³. What is the density of the olive oil?
A student determines the volume of an irregular stone by lowering it into a measuring cylinder containing water. The water level rises from 35.0 cm³ to 95.0 cm³. The stone has a mass of 156 g. What is the density of the stone in kg m⁻³?
An object has a density of 3.5 g cm⁻³. What is this density expressed in kg m⁻³?
Density is inversely proportional to volume when mass is constant. A sample of gas has a density of 1.2 kg m⁻³ at a certain pressure. If the gas is compressed so that its volume is halved while its mass remains the same, what is its new density?
Explain which method — measuring dimensions with a ruler or using the displacement method — is more appropriate for determining the volume of a steel sphere, and why.
A student needs to determine the density of a small, irregularly shaped pebble. Which sequence of steps is correct?
The table shows the densities of four materials and of a liquid. [table] Material / Density / kg m⁻³ ; Pine wood / 500 ; Ice / 920 ; Brick / 1900 ; Copper / 8900 ; Liquid (glycerine) / 1260 Which materials will float when placed in glycerine?
A solid block has a mass of 0.810 kg and dimensions 0.10 m × 0.05 m × 0.06 m. Calculate the density of the block in kg m⁻³.
A cube of side length 3.0 cm has a mass of 54 g. Calculate the density of the cube in g cm⁻³.
When determining the density of a liquid, the student first measures the mass of the empty measuring cylinder. Which statement best explains why this step is necessary?
A deep-sea diver drops a solid plastic ball and a solid glass marble into seawater (density 1025 kg m⁻³). The plastic ball has a density of 850 kg m⁻³ and the glass marble has a density of 2500 kg m⁻³. A nearby wooden plank has a density of 1025 kg m⁻³. What happens to each object?
A student measures the mass of a metal sphere as 340 g. She intends to calculate its density in kg m⁻³ and converts the mass to 0.340 kg but forgets to convert the volume from cm³ to m³. The volume she measured was 40.0 cm³. What incorrect density value does she obtain, and in which direction is her error?
A student uses the displacement method to find the volume of a stone but notices air bubbles clinging to the surface of the stone after submerging it. How does this affect the calculated density?
An engineer needs to select a material for a flotation device that must float in seawater (density 1025 kg m⁻³) but sink in ethanol (density 789 kg m⁻³). Which material density would meet both requirements?
Three immiscible liquids — P, Q, and R — have densities of 1080 kg m⁻³, 730 kg m⁻³, and 960 kg m⁻³ respectively. They are poured into the same container. Which row correctly shows the arrangement of liquids from top to bottom?
A container holds two immiscible liquids: liquid X (density 850 kg m⁻³) floating on liquid Y (density 1200 kg m⁻³). A solid sphere with a density of 1000 kg m⁻³ is gently placed into the container. What happens to the sphere?
A student measures the mass and volume of five identical copper cubes and plots a graph of mass (y-axis) against volume (x-axis). The graph is a straight line through the origin. What does the gradient of this line represent?
A metal block has a mass of 480 g and a density of 8.0 g cm⁻³. Calculate the volume of the block.