Lesson on Disaster Readiness and Risk Reduction

1. Read the sample situation then answer the questions that follow.
1.Suppose there are 10 g of sodium chloride (NaCl) and 10 g of 10 g of
water (H2O) , do they have the same number of particles?
2. What about 2500 particles of sugar and 2500 particles of sulphur, do
they have the same masses?

2. Procedure:
1. Measure and record the mass in grams of the following in the table below.
5 pieces plastic bottle cap (must be of the same brand)
5 pieces soft drink crown of the same brand
5 pieces 1-peso coin
2. From the data you obtained from procedure 1, compute for the mass of 1 piece
and 15 pieces for each kind of material.
3. Measure approximately 25.00 g of each material
Materials Mass (g)
5 pieces
Mass (g)
1 piece
Mass (g)
15 pieces
Number of pieces
In 25.00 g
Plastic bottle
cap
Soft drink crown
1-peso coin

3. Guide Questions:
1.Do the three different materials have the same masses?
Explain your answer.
2.Was your expected number of pieces per material the same
with the number of pieces equal to 25.00g?
3.What can you infer from the result of the activity?

4. You have observed from this activity that although you have the same number of
items, different objects will have different masses. In the same way, one mole of
different substances always contains 6.02 x 1023 particles but each of these
substances has a different mass. Examine the sample substances in Table 2. You
will observe that each of the substances contains 6.02 x 1023 particles.
Substances Chemical
Formula
Molar Mass
(g/mol)
Number of particles
Oxygen gas O2 32.00 6.02 x 1023
Sucrose (table
sugar)
C12H22O11 342.34 6.02 x 1023
Hydrogen peroxide H2O2 34.02 6.02 x 1023
Elemental calcium Ca 40.08 6.02 x 1023

5. Directions: Consult the periodic table of elements. Look for the atomic mass of
the following, then record.
Elements Atomic Mass
1. Hydrogen (H) _______________
2. Oxygen (O) _______________
3. Carbon (C) _______________
4. Sulphur (S) _______________
5. Potassium (K) _______________
6. Phosphorus (P) _______________
Answer the following questions:
1. What do you observe about their atomic masses?
The atomic masses of elements are different from one another.
2. What can you infer from the data above?
Each element has its own mass different from the others in the same way
that different compounds have different masses.

6. Assignment:
•Study on the relationship among the
Number of Moles, Mass and Number of
Particles