Classifications of Matter Matter is anything that occupies space and has mass. mass - a measure of the quantity of matter Volume - space
Classifications of Matter
Matter is anything that occupies space and has mass.
mass - a measure of the quantity of matter
Volume - space
Physical and Chemical Properties of Matter
Properties
A set of characteristics by which a substance can be recognized
can be measured and observed without changing the composition or identity of a substance
densitycolor odortaste
hardnessmelting pointboiling point
Physical Property
Extensive property
depends on amount of material; mass and volume are examples of extensive properties
Intensive property
does not depend on amount of material; density and temperature are examples of intensive properties
mass,volume, length....
density, temperature...
requires a chemical change in order to be observed
the ability of a substance to combine with or change into one or more substances.
old substance gone
new substance formed
Chemical Property
has its own definite shape an volume. Tightly packed particles make solids incompressible.
The Three States of Matter
has a constant volume but conforms to the shape of its container. Particles are not rigidly held in place and are less closely packed.
Solid
Liquid
gasconforms to both the shape and the volume of its container. Particles are very far apart which makes gases very compressible.
solid liquid gas
Physical change
alters a substance without changing the composition
Tearing paperMelting waxPhase changes
examples:
Chemical changeone or more substances changing into new substances
words that signify a chemical change:
BurningRottingRustingExploding
Cellular respirationexamples:
Evidence of a Chemical ReactionThe following are indicators that a chemical reaction has taken place:
- Color change
- Effervescence
– Evolution of gas
Evidence of a Chemical Reaction cont.
- Evolution of light
- Odor
– Formation of a Precipitate
Chemical Reactions
Chemical bonds have been broken and new chemical bonds have been formed
2H2 + O2 2H2O(g) (g) (g)
Chemical Reactions
2H2 + O2 2H2O(g) (g) (g)
Reactants: elements or compounds to the left of the arrow that combine together in a chemical reaction
Chemical Reactions
2H2 + O2 2H2O(g) (g) (g)
Reactants: elements or compounds to the left of the arrow that combine together in a chemical reaction
Products: elements or compounds to the right of the arrow that produced in a chemical reaction
Joseph Priestley and Antoine–LaurentLavoisier — 18th century- Demonstrated that combustion is a reaction between matter and oxygen
Law of Conservation of Mass- matter can neither be created nor destroyed
Massreactants
Massproducts
=
2 Hg
216 g 16 g 200 g
Start: 0 0 216 g
200 g Finish: 0 16 g
2 HgO O2 +
The thermal decomposition of mercury II oxide.
from a laboratory process designed to separate water into hydrogen and oxygen, a student collected 10.0 g of hydrogen and 79.4 g of oxygen. How much water was originally involved in the process?
practice problem 6
2H2 + O2 (g) (g)(g)2H2O
10g 79.4g
Start:
Finish:
?89.4g
a student carefully places 15.6 g of sodium in a reactor supplied with an excess quantity of chlorine gas. When the reaction was complete, the student obtained 39.7 g of sodium chloride. How many grams of chlorine gas reacted? How many grams of sodium reacted ?
practice problem 7
excess 39.7 gFinish: 0
2Na Cl2 2NaCl+
15.6 gStart: excess24.1g
Matter
Mixture Substance
Homogeneousmixtures
Heterogeneousmixtures
Compounds
Elements
Matter
Mixture Substance
Homogeneousmixtures
Heterogeneousmixtures
Compounds
Elements
click on words for definitions
Based on the difference in boiling points of the mixed substances
Distillation
Separating Mixtures
CrystallizationResults in the formation of solid particles of a substance from a solution containing the dissolved stance
Chromatographyseparates the components of a mixture (mobile phase) on the basis of the tendency of each to travel across the surface of another material (stationary phase)
Periodic Table of the Elements
Chemical Symbols
abbreviations for the names of the elements
the first letter is always capitalized
O, Al, C, Cl, H, He…….
An elements position on the periodic gives indications of its various physical and chemical
properties
Main groupsgroup numbers indentified by suffix A
Main group metalsAlkali metals Alkaline earth metals
NonmetalsHalogens Noble gases
transition metalsLanthanidesActinides
transition metalsLanthanides
What makes water,
H2O
water ?
1 L2 L
+ (g)(l) (g)O22H22H2O
+
32.0 g4.0 g
+ (g)(l) (g)O22H22H2O
+
36.0 g
+ (g)(l) (g)O2HH2O
+
16.0 g2.0 g18.0 g
18.0 g H2O
18.0 g H2O
16.0 g O
2.0 g Hx 100 %
x 100 % = 88.9 % O
= 11.1 % H
+ (g)(l) (g)O2HH2O
32.0 g O
4.0 g H
+ (g)(l) (g)O22H22H2O
36.0 g H2O
36.0 g H2O
x 100 %
x 100 % = 88.9 %
= 11.1 %
Joseph Proust — 18th century
Chemistry Timeline
Law of Definite Proportions- different samples of the same compound always contain its constituent elements in the same proportions by mass
- the proportions can be found by calculating the percent by mass
Percent by mass
based on the law of conservation of mass
Masscompound
the sum of the Masseselements
=
% by mass =mass of the element
mass of the compoundx 100 %
20.00 g of Sucrose is a compound made up of Carbon, Hydrogen and Oxygen
Example page 75
Carbon
Hydrogen
Oxygen
8.44 g
1.30 g
10.26 g
20.00 g Sucrose
8.44 g C
1.30 g H
10.26 g O20.00 g Sucrose
20.00 g Sucrose
20.00 g Sucrosex
x
x
100%
100%
100%
= 42.2 % C
=
=
6.50 % H
51.30 % O
500.0 g of Sucrose is a compound made up of Carbon, Hydrogen and Oxygen
Example page 75
Carbon
Hydrogen
Oxygen
211.0 g
32.5 g
256.5 g
500.0 g Sucrose
211.0 g C
32.5 g H
256.5 g O500.0 g Sucrose
500.0 g Sucrose
500.0 g Sucrosex
x
x
100%
100%
100%
= 42.2 % C
=
=
6.50 % H
51.30 % O
A 78.0 g sample of an unknown compound contains 12.4 g of hydrogen. What is the percent by mass of hydrogen in the compound ?
practice problem 20
% Hydrogen =12.4 g H
78.0 g compoundx 100% = 15.9 % H
If 1.0 g of hydrogen reacts completely with 19.0 g of fluorine, what is the percent by mass of hydrogen in the compound that is formed ?
practice problem 21
% Hydrogen =1.0 g H
20.0 g compoundx 100% = 5.0 % H
19.0 g F + 1.0 g H = 20.0 g compound
If 3.5 g of X reacts with 10.5 g of Y, what is the percent by mass of X in the compound that is formed ?
practice problem 22
% X =3.5 g X
14.0 g compoundx 100% = 25 % X
3.5 g X + 10.5 g Y = 14.0 g compound
% Y =10.5 g Y
14.0 g compoundx 100% = 75 % Y
Two unknown compounds are tested. Compound 1 contains 15.0 g hydrogen and 120.0 g oxygen. Compound 2 contains 2.0 g hydrogen and 32.0 g oxygen. Are the compounds the same ?
practice problem 23
Two unknown compounds are tested. Compound 1 contains 15.0 g hydrogen and 120.0 g oxygen. Compound 2 contains 2.0 g hydrogen and 32.0 g oxygen. Are the compounds the same ?
practice problem 23
% H =15.0 g H
135.0 g compoundx 100% = 11.1 % H
% O =120.0 g O
135.0 g compoundx 100% = 88.9 % O
Two unknown compounds are tested. Compound 1 contains 15.0 g hydrogen and 120.0 g oxygen. Compound 2 contains 2.0 g hydrogen and 32.0 g oxygen. Are the compounds the same ?
practice problem 23
% H =2.0 g H
34.0 g compoundx 100% = 5.9 % H
% O =32.0 g O
34.0 g compoundx 100% = 94.1 % O
11.1 % H
88.9 % O
5.9 % H
94.1 % O
Two unknown compounds are tested. Compound 1 contains 15.0 g hydrogen and 120.0 g oxygen. Compound 2 contains 2.0 g hydrogen and 32.0 g oxygen. Are the compounds the same ?
practice problem 23
Compound 1
Compound 2
No these are not the same compounds
John Dalton — 19th century
Chemistry Timeline
Law of Multiple Proportions- if two elements can combine to form more than one compound, the masses of one element that combine with a fixed mass of the other elements are in ratios of small whole numbers
Mass of nitrogen that combines with 1g of oxygen
Example
Compound 1 1.750g
Compound 2 0.8750g
Compound 3 0.4375g0.4375g
0.4375g
0.4375g=
=
=
4
2
1
Whole number ratios
mass ratio compound
2
1 64.20
47.27
35.80
52.73
1.793 g Cu/ 1 g Cl
0.8964 g Cu/ 1 g Cl= 2
% Cu % Cl
64.20
47.27 52.73
35.80
mass copper (g) in 100.0 g of compound
mass Chlorine (g) in 100.0 g of compound
1.793 g Cu/ 1 g Cl
0.8964 g Cu/ 1 g Cl
mass Cumass Chlorine
Multiple Proportions
(slides that follow are linked to earlier ones)
a substance is form of matter that has a definite or constant composition and distinct properties, for example
waterammoniatable sugargoldoxygen
a mixture is a combination of two or more substances in which the substances retain their distinct indentities, for example
airmilkcement
the composition of a homogeneous mixture is the same throughout, for example
sugar dissolved in water
a mixture of nonuniform composition is a heterogeneous mixture, for example
airSand and iron filings
an element is a substance that cannot be separated into simpler elements by
chemical means
a compound is a substance composed of atoms of two or more elements chemically united in fixed
proportions