Volume, Mass and Density

Volume, Mass and Density

= &nb= sp; = Solid 1 = &nb= sp; = &nb= sp; = Solid 2

Which solid has more mass (atoms-molecules-ions)= in the same volume (space)? ____________

I= t’s Density

We can calculate density using the formula:

Den= sity=3D Mass/Volume

Since mass is usually expressed in grams and volume in cm ³, density is expressed in gm/cm³

Density

Density relates the mass of a substance to its volume through the formula: D =3D M/V= . From a density calculation, we may assess whether a substance will float or sink in any given medium and may also obtain a clue as to the identity of the substance.

Regular Solids:

1. To calculate the density o= f any type of matter you must first obtain the mass of the sample
and its volume.

2. The mass may be obtained through th= e use of a triple-beam or electronic balance.

3. Make note of the metric unit that y= ou are using to report the mass. (grams g)

4. Volum= e of the substance may be measured in a variety of ways.

5. For regular solids, those whose form is one of the standard geometric shape= s, use a metric
     ruler to m= ake the necessary measurements and use these values to solve for the volume of = the
    object. For a rectangular solid, volume = =3D length x width x height.
6. When both the mass and vol= ume of the object is known, insert these values into the density
     formula and solve the equation. The proper unit for the density of the object is the un= it of its
     mass over = the unit of its volume, for example - g/ml.
7. Some examples of regular solids are= : Box, Cylinder, Sphere and Cone

Sample Problems

1. Find = the density of a 14 g regular solid measuring 3 cm x 5 cm x 4 cm.

Does it fl= oat in water? ______________________

2. Find = the density of a 25 g regular solid measuring 3.5 cm x 3.5 cm x 3.5 cm.

Does it fl= oat in water? ______________________

Density

I= rregular Solids:

1. To ca= lculate the density of any type of matter you must first obtain the mass of the sam= ple
and its volume.
2. The mass may be obtained t= hrough the use of a triple-beam or electronic balance.

3. Make note of the metric unit that y= ou are using to report the mass. (grams g)

4. Volum= e of the substance may be measured in a variety of ways
5. For irregular solids, those whose form is one of an irregular shape, the displacement method
must be us= ed to determine their volume in milliliters mL.

6. Choos= e a graduated cylinder large enough to hold the object.

7. Fill = the cylinder half-way with water (enough water to cover the object completely, = but not so
    much that when the object is added,= the level of the water rises above the point that the
     cylinder c= an measure) and note the exact volume of the water.
8. Add the object to the wate= r in the cylinder, taking care not to splash the water out of the
    cylinder.
9. Note the new volume in the graduated cylinder.
10. Because 1ml of water is equal to 1 cubic centimeter of water, the volume of the object is
      equal to the new volume in the grad= uated cylinder minus the original volume of water.

11. When both the mass and volume of the object is kno= wn, insert these values into the density
form= ula and solve the equation. The proper unit for the density of the object is the unit of its
mass over the unit of its volume, f= or example - g/ml.

Sample Problems

1. Find = the density of a 14 g irregular solid that displaces 7 mL<= /span> of water.

2. Find the density of a 50 g irregular solid placed in 75 milliliters (mL) of water noting the
new volume= of 100 mL with the objected added to the water.

= &nb= sp;