chemistry
dalton’s deduction
name:
date:
Concept: Compounds are substances having definite composition that can be chemically decomposed.
The Law of Conservation of Mass states that in ordinary chemical reactions mass is neither created nor
destroyed. Based on this notion, complete the following mass amounts by examining the following
equations:
Example A.) hydrogen + oxygen  (produces) water.
___ g
16.0 g
18.0 g
Example B.) copper + oxygen  copper oxide
63.5 g
16.0 g
______ g
TABLE 1
Sample
Grams of oxygen
Grams of tin
1
2
3
1.5075 grams
2.5995 grams
4.2376 grams
11. 189 grams
19. 294 grams
31.452 grams
Total grams of tin
oxide
12.696 grams
21.894 grams
35.690 grams
Use the data in TABLE 1 to answer questions 1-5.
1.) What are the % oxygen and the % tin in the sample one of tin oxide?
Mass of oxygen/total grams x 100 = ____________%
Mass of tin/total grams x 100 = ____________%
2.) Law of Definite Composition states that a compound always contains exactly the same proportion of
elements by mass. If this combination of tin and oxygen were the same what would expect the %Sn in
sample 2 and sample 3. Explain.
3.) What is the fraction of tin: oxygen in sample 2 and sample 3.
Use the Formula: grams O/ grams Sn = ____________
4.) How many grams Oxygen are present per 1.00 g of tin?
5.) If the tin oxide compound were composed of equal number tin and oxygen particles how would you
write the formula? Write Sn first.
chemistry
dalton’s deduction
name:
date:
Use the data in Table 2 to answer questions 6-10.
TABLE 2
Sample Grams of oxygen
Grams of tin
total grams of tin oxide
1
4.9608 g
18.431 g
23.392 g
2
12.381 g
46.000 g
58.381 g
6.) What are the % oxygen and the % tin in the first sample of tin oxide?
Mass of oxygen/total grams x 100 = ____________%
Mass of tin/total grams x 100 = ____________%
7.) What is the fraction of oxygen: tin in sample 1 and sample 2.
Use the Formula: grams O/ grams Sn = ____________
8.) How many grams Oxygen are present per 1.00 g of tin.
9.) Does the data suggest that the tin oxide in table 2 is a different compound? Explain.
10.) Are the two sets of data in Table 1 and Table 2 representative of one or two separate compounds of
tin oxide? Explain.
11.) The Law of Multiple Proportions states: When two elements form a series of compounds, the ratios
of the masses of the second element that combine with 1 grams of the first element can always be
reduced to small whole numbers. Divide the ratio from the second table by the ratio from the first table.
Record your answers.
12.) What do you think is the formula for the second tin oxide compound?
Dalton studied these three laws. Suppose matter consists of unbreakable particles that can be joined,
separated or rearranged. If these unbreakable particles (atoms) have specific and unique masses that
are neither destroyed nor created by chemical change then mass must be conserved. These unbreakable
particles could join to form a compound in specific ratios that would correspond to elements having
definite composition by mass. The law of multiple proportions could explain why the mass ratio of second
element is in whole number ratios if the atoms or unbreakable particles themselves were in the same
whole number ratio.
13.) In determining the formula for both tin oxide compounds we supposed that compounds were made of
elementary particles. Dalton looked at data such as this and proposed that matter is ultimately composed
of particles called ______________. The beginning of the atomic theory rests on the Law of
Conservation of Mass, Law of Definite proportions, and Law of Multiple Proportions.