**Problem: **You
are given two unknown liquids. Find the density of each.

**Materials:** 100ml graduated cylinder, triple beam balance, calculator, 2 unknown liquids.

**Procedure:** 1) Find the mass of the empty graduated cylinder.

2) Pour unknown liquid #1 into the graduated cylinder to the **50 ml**.
level.

3) Find the mass of the graduated cylinder with 50ml of unknown liquid #1.

4) Repeat steps 1-3 for unknown liquid #2.

We can calculate density of a each liquid using the formula:

**Density=
Mass/Volume**

where mass is that
for __just the liquid__ (you must subtract out the mass of the graduated cylinder).

Now let's calculate the densities of the two liquids using the following given data.

**Liquid
#1:**

__Given: __Mass of empty graduated
cylinder = __78 grams__

Mass of graduated cylinder
with unknown liquid #1= __128 grams__.

Find:

a) Mass of just the liquid = ____

b) Volume of liquid=_____

c)
Density of liquid #1 =____

**Liquid #2:**

__Given: __Mass of empty graduated cylinder = __78 grams__

Mass
of graduated cylinder with unknown liquid #2= __117.5 grams__.

Find:

a) Mass of just the liquid = ____

b) Volume of liquid =_____

c)
Density of liquid #2=____

Check your answers by inserting the value in the box below.

**Density of
Liquid 1:**

**Density
of Liquid 2:**

Using the table below it is now possible for you to determine what each liquid is.

Substance |
Density (gm/cu.cm) |

>Water | 1.00 |

Cooking oil | 0.92 |

Sea Water | 1.025 |

Carbon tetrachloride | 1.58 |

Benzene | 0.87 |

Glycerin | 1.26 |

Methanol | 0.79 |

**Unknown liquid #1 is:**

**FINDING THE DENSITY OF A LIQUID
USING A HYDROMETER**The density of a liquid
can also be measured using a simple device known as a hydrometer.Literally
meaning "water measurer," a hydrometer is an instrument comprised of
a vertical scale inside a sealed glass tube weighted at one end. It's used to
measure the ratio (called specific gravity) of the density of a liquid grape to
that of pure water. A hydrometer is basically a sealed
tube which is narrow at the top and is weighted with a dense material such as
lead at the bottom. You may have seen one in a salt-water fish aquarium. The hydrometer
is often considered the most valuable tool in wine making.
When a hydrometer is inserted into a liquid, the tube floats vertically so that
the narrow part sticks out of the liquid while the heavy end sinks. The narrow
part is calibrated for the density. The hydrometer floats higher in liquids of
higher density and lower in liquids of lower density.

Please
return to the **Science
and Math Activity Home Page** and try another activity.

Mass: Learn how to measure the mass of an object using a triple beam balance

Mass vs. Weight: Mass and weight are often confused by many students. Learn the difference and try some challenging problems.

Volume: Measure volume using a graduated cylinder.

Density of a Solid: Learn to calculate the density of an unknown solid from knowing its mass and volume.

Density of a Liquid: Learn to calculate the density of an unknown liquid from knowing its mass and volume using a graduated cylinder and triple beam balance. Learn what a hydrometer is, and what it can do.

Density Challenge: Great page for gifted and talented students! Some excellent challenging problems.

Assessment: Twenty questions on mass, volume and density (two levels of difficulty). Your test is marked online.

Science Project Ideas: Ideas for science projects using mass, volume and density concepts learned from this module.

Mass Volume Density Lab Exercise: Problem: What is the relationship between water pressure and depth of water?

An Integrated Math Science and Art (STEAM) Activity- Mass, Volume Density Activity using the Gates Project from Central Park NYC.