Core Practical: Determining Density

equipment

ruler, vernier calipers, micrometer, digital balance, eureka can, measuring cylinder

ruler resolution

1 mm

vernier resolution

0.01 mm

micrometer resolution

0.001 mm

balance resolution

0.01 g

regular object aim

determine density using dimensions

regular object independent variable

type of shape, or volume

regular object dependent variable

mass

regular object method

measure mass, measure dimensions, calculate volume, calculate density

regular object repeat

take multiple readings, and average

irregular object aim

determine density using displacement

irregular object independent variable

different irregular shapes

irregular object dependent variable

volume of displaced water

irregular object method

measure mass, fill eureka can, lower object, measure displaced water

irregular object volume rule

displaced water volume = object volume

liquid density aim

determine density by mass difference

liquid method

measure empty cylinder mass, add liquid, measure new mass

liquid mass formula

mass of liquid = mass full − mass empty

density formula

density = mass ÷ volume

systematic error

zero the balance before measuring

random error

take repeat readings, and average

irregular object caution

lower object gently to avoid splashing

safety

handle glassware carefully

safety

do not pour water onto balance

safety

stand up to react to spills

exam tip

state equation, list apparatus, describe measurements, repeat and average