1. Chemistry 1 Chapter 2 Matter & Change

2. Mass – (g) amount of matter in an object
Density
Mass – (g) amount of matter in an object
Volume – (mL) amount of space occupied by an object
Density – (g/mL) a ratio of mass to volume

3. m D = Formula: Rewrite this formula to solve for m & v!
What is the unit for Density????
Remember: A material has the same density no matter how big or small it is!

4. Example:
A piece of metal has a volume of 4.70 mL and a mass of 57.3 g. What is the density?
M = 57.3 g
V = 4.70 mL
D = M / V
D = 57.3 g / 4.70 mL
D = g/mL
D = 12.2 g/mL

5. Intensive vs. Extensive
Intensive Properties – Do NOT depend on amount
Examples: density
Extensive Properties – Depends on amount
Examples: Mass, volume

6. Problem A piece of copper has a mass of 57. 54 g. It is 9
Problem A piece of copper has a mass of g. It is 9.36 cm long, 7.23 cm wide, and 0.95 mm thick. Calculate density (g/cm3). M V D

7. Strategy 1. Get dimensions in common units.
2. Calculate volume in cubic centimeters.
3. Calculate the density.

8. Learning Check
Osmium is a very dense metal. What is its density in g/cm3 if g of the metal occupies
a volume of 2.22cm3?
1) g/cm3
2) 22.5 g/cm3
3) 111 g/cm3

9. Volume Displacement 25 mL
A solid displaces a matching volume of water when the solid is placed in water.
33 mL
25 mL

10. Learning Check
What is the density (g/cm3) of 48 g of a metal if the metal raises the level of water in a graduated cylinder from 25 mL to 33 mL?
1) 0.2 g/ cm ) 6 g/cm ) g/cm3
33 mL
25 mL

11. Learning Check
Which diagram represents the liquid layers in the cylinder?
(K) Karo syrup (1.4 g/mL), (V) vegetable oil (0.91 g/mL,) (W) water (1.0 g/mL)
1) ) ) K V W K V W W V K

12. Solution
(K) Karo syrup (1.4 g/mL), (V) vegetable oil (0.91 g/mL,) (W) water (1.0 g/mL) 1) V W K

13. Learning Check
The density of octane, a component of gasoline, is g/mL. What is the mass, in kg, of 875 mL of octane?
1) kg
2) 614 kg
3) 1.25 kg

14. Learning Check
If blood has a density of 1.05 g/mL, how many liters of blood are donated if 575 g of blood are given?
1) L
2) L
3) L

15. Graphs of density and volume can be used to find the density of a substance. The slope of the line formed when mass and volume are plotted is the density. Remember “rise over run”.

16. Scientific Method 5 Steps: 1. Problem 2. Hypothesis 3. Experiment
4. Observations & Data
5. Conclusion 16

17. 1) Problem -
“What’s wrong?” 17

18. 2) Hypothesis - “Educated Guess” predict what will happen
Based on prior knowledge 18

19. 3) Experiment - Test your hypothesis
a) Control Group – stays the same, used for comparison
b) Variable Group – what you
manipulate that changes 19

20. 1. Independent Variable – what the experimenter (I) changes.
2. Dependent Variable – what is observed/measured.
The dependent variable depends on the independent variable
The independent variable is what I change!!! 20

21. 3. Control Variables – all other variables that are kept constant.
Remember, a good experiment only has two variables that change (independent and dependent). All the rest of the variables must be the same. 21

22. when graphing… 22

23. 4) Observations
&
Data collection 23

24. 5) Conclusion -
- Based on observations
Might support hypothesis! 24

25. What’s the MATTER? Matter Mass
is defined as anything that has mass and takes up space.
Mass
is the amount of matter an object contains.

26. A substance is matter that has uniform and definite composition.
Pure substances contain only one kind of matter.
NaCl Cr
Element
Compound

27. Physical Property is a quality or a condition of a substance that can be observed or measured without changing the substance’s composition.
Color
Size
Hardness
Density
Shape

28. States of Matter
Solid
Liquid
Gas
Name examples of each…

29. Phases of Matter
Solid Liquid Gas

30. Change in matter without changing the chemical composition.
Physical Change
Change in matter without changing the chemical composition.
Examples:
Boiling
Freezing
Melting
Condensing
Breaking
Splitting
Cracking
Grinding
Cutting
Crushing
Bending

31. - Chemical Change – one or more substances changing into a new substance.
Signs of a chemical change:
1. Bubbling
2. Change in Temp
3. Color Change
4. Change in Smell

33. 2.2 Mixture Heterogeneous a physical blend of two or more substances.
not uniform in composition
Examples:
Muddy Water
Chocolate-Chip Cookie
Salad

34. Solutions are homogeneous mixtures. They consist of one phase.
completely uniform in composition
Examples:
Milk
Salt water
Solutions are homogeneous mixtures. They consist of one phase.

35. Phase
any part of a system with uniform composition and properties.
Heterogeneous mixtures
consist of two or more phases.
Liquids can be separated by distillation. One liquid is boiled then cooled so it will condense again into a liquid.

36. 2.3 Element Examples: Al C Hg
The simplest form of matter that can exist under normal laboratory conditions.
Examples: Al C Hg

37. Compound Examples: AlCl3 NaCl H2CO3 CH3OH
A substance that can be separated into simpler substances only by chemical means.
Examples:
AlCl3
NaCl
H2CO3
CH3OH

39. Classify the following as an element, compound or mixture:
C12H22O11
Table sugar
Water
Iron
Vegetable Soup
Salt water O2
CaCO3
Air
Compound
Element
Mixture

40. mass of reactants = mass of products
2.4
Law of Conservation of Mass
Mass is neither created nor destroyed in chemical reactions.
mass of reactants = mass of products
In a chemical reaction, the numbers and kinds of atoms present in the products are the same as those present in the reactants.

41. In a Chemical reaction two or more substances change into new substances.
Reactants  Products
Example:
Li + KCl  LiCl + K