Chapter 1 Matter

1-1 Scientific Method: A systematic approach to solving problems. Does not guarantee scientific success Many discoveries made by accident

1-2 Properties of Matter: Matter: Anything that has mass and takes up space.

Physical Properties: Chemical Properties: Can be observed without changing a substance into another substance. Color, Boiling point, density, mass, volume, etc. Chemical Properties: Can only be observed when a substance is changed into another substance. Flammability, corrosiveness, reactivity with acid, etc.

Intensive Properties: Independent of the amount of the substance that is present. Density, boiling point, color, etc. Extensive Properties: Dependent upon the amount of the substance present. Mass, volume, energy, etc.

Changes of Matter Physical Changes: Chemical Changes (Reactions): Changes in matter that do not change the composition of a substance. Changes of state, temperature, volume, etc. Chemical Changes (Reactions): Changes that result in new substances. Combustion, oxidation, decomposition, etc.

1-3 Classification of Matter Atoms are the building blocks of matter. Each element is made of the same kind of atom. A compound is made of two or more different kinds of elements. Molecules are the smallest units of compounds.

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Mixture: Composition varies from sample to sample Substance (pure): Composition and properties are uniform in every sample elements and compounds Mixture: Composition varies from sample to sample Homogeneous Mixture: uniform composition AKA solutions (air, salt water, gasoline) Heterogeneous Mixture: components separate into regions Italian dressing, sand and water

Separating Mixtures Mixtures can be separated into components by physical means

Distillation: Separates homogeneous mixture on the basis of differences in boiling point.

Chromatography: Separates substances based on differing abilities of compounds to adhere to the surface of a solid

Filtration: Separates solid substances from liquids and solutions.

States of Matter

Inks and food coloring are typically composed of many different dyes which can be separated by paper chromatography. Which of the following terms apply to inks? 1. substance 2. homogenous 3. compound 4. element 5. heterogeneous

Inks and food coloring are typically composed of many different dyes which can be separated by paper chromatography. Which of the following terms apply to inks? 1. substance 2. homogenous 3. compound 4. element 5. heterogeneous

Which of the following separations cannot be achieved using a physical process and, therefore, requires a chemical process? 1. salt from sea water 2. water from honey 3. hydrogen from water 4. ice from water 5. fish from water

Which of the following separations cannot be achieved using a physical process and, therefore, requires a chemical process? 1. salt from sea water 2. water from honey 3. hydrogen from water 4. ice from water 5. fish from water

1-4 Measurement of Matter

SI Units Système International d’Unités

Metric System Prefixes convert the base units into units that are appropriate for the item being measured.

What is the name given to the unit that equals: 10–9 gram 10–6 second 10–3 meter

SI Unites Mass: quantity of matter in an object Time: seconds (s) Grams (g) Time: seconds (s) Volume: liter (L) and the milliliter (mL) 1 mL = 1 cm3

The volume of the cube to the right is 10.0 cm 1. 1.00 L 2. 100 mL 10.0 cm 3. 1.00 kL 4. 30 cm3 10.0 cm 5. 1.00 dL

The volume of the cube to the right is 10.0 cm 1. 1.00 L 2. 100 mL 10.0 cm 3. 1.00 kL 4. 30 cm3 10.0 cm 5. 1.00 dL

Temperature: A measure of the average kinetic energy of the particles in a sample. Celsius and Kelvin scales are most often used. The Celsius scale is based on the properties of water. 0C is the freezing point of water. 100C is the boiling point of water.

Temperature The Kelvin is the SI unit of temperature. It is based on the properties of gases. There are no negative Kelvin temperatures. K = C + 273.15 F = 9/5(C) + 32 C = 5/9(F − 32)

d= m V % Comp= Part Total 1-5 Density and % Comp Example Problems

1-6 Uncertainties in Measurements Systematic errors (built in errors) Thermometer constantly 2°C too low. Random errors Limitation in reading a scale. Precision Reproducibility of a measurement. Accuracy How close to the real value.

General Chemistry: Chapter 1 Precision Reproducibility ∼ 0.1 g ∼ 0.0001 g Precision low high General Chemistry: Chapter 1

1-7 Significant Figures The term significant figures refers to digits that were measured. When rounding calculated numbers, we pay attention to significant figures so we do not overstate the accuracy of our answers.

Significant Figures All nonzero digits are significant. Zeroes between two significant figures are themselves significant. Zeroes at the beginning of a number are never significant. Zeroes at the end of a number are significant if a decimal point is written in the number. Pacific/Atlantic Trick

Significant Figures When addition or subtraction is performed, answers are rounded to the least significant decimal place. When multiplication or division is performed, answers are rounded to the number of digits that corresponds to the least number of significant figures in any of the numbers used in the calculation.

First consider the units that need to be converted Dimensional Analysis The average speed of a nitrogen molecule in air at 25°C is 515 m/s. Convert this speed to miles per hour. First consider the units that need to be converted Now find equalities between the units

1 m = 3.28 ft 1 mi = 5280 ft 1 hr = 3600 s Now substitute the numbers Ans 1151.73 mi/hr

What is the mass in lbs of 1. 00 gal of water What is the mass in lbs of 1.00 gal of water? The density of water is 1.00 g/mL. 1.0 gal = 3.79 L 1 L = 1000mL 1 lb = 454 g 8.33lbs

Blood plasma for adults is about 3. 1 L. Its density is 1. 020 g/cm3 Blood plasma for adults is about 3.1 L. Its density is 1.020 g/cm3. How many pounds of blood plasma are there in your body? ( 1 lb = 453.6 g)

The average density of a human brain is 0. 90 g cm-3 The average density of a human brain is 0.90 g cm-3. Which of the following is the correct process to convert g cm-3 to kg L-1?

The average density of a human brain is 0. 90 g cm-3 The average density of a human brain is 0.90 g cm-3. Which of the following is the correct process to convert g cm-3 to kg L-1?

The density of the earth is about 4 g ml-1 The density of the earth is about 4 g ml-1. Which of the following is the correct process to convert g ml-1 to kg m-3? From NASA files

The density of the earth is about 4 g ml-1 The density of the earth is about 4 g ml-1. Which of the following is the correct process to convert g ml-1 to kg m-3? From NASA files

The red ball at the bottom is less dense than the black ball on top. A Galileo thermometer functions based on the dependence of density on temperature. Which of the following statements is correct? black The red ball at the bottom is less dense than the black ball on top. The red ball is less dense than the liquid in the cylinder. 3. The black ball at the top is more dense than the blue ball on the bottom. 4. The black ball at the top is less dense than the liquid in the cylinder. Slide 43 of 27

red A Galileo thermometer functions based on the dependence of density on temperature. Which of the following statements is correct? black The red ball at the bottom is less dense than the black ball on top. The red ball is less dense than the liquid in the cylinder. 3. The black ball at the top is more dense than the blue ball on the bottom. 4. The black ball at the top is less dense than the liquid in the cylinder.

Which of the following expresses the result of the following calculation with the correct number of significant figures? 31.621 cm x 10.22 cm x 2.793292 cm = 1. 9.027 x 102 cm 2. 9.0269 x 102 cm3 3. 9.027 x 102 cm3 4. 9.026 x 102 cm3 5. 9.0 x 102 cm3

Which of the following expresses the result of the following calculation with the correct number of significant figures? 31.621 cm x 10.22 cm x 2.793292 cm = 1. 9.027 x 102 cm 2. 9.0269 x 102 cm3 3. 9.027 x 102 cm3 4. 9.026 x 102 cm3 5. 9.0 x 102 cm3

Which of the following expresses the result of the following calculation with the correct number of significant figures and appropriate units? 86.31246762 g cm-3 x 10.5 cm3 = 906.3 g 906.28091 g cm3 906.2 g cm-6 906.28 g 906 g

Which of the following expresses the result of the following calculation with the correct number of significant figures and appropriate units? 86.31246762 g cm-3 x 10.5 cm3 = 906.3 g 906.28091 g cm3 906.2 g cm-6 906.28 g 906 g

Which of the following do you think would be the best unit of measure to express the height of the Eiffel tower. 1. centimeters 2. nanometers 3. gigameters 4. meters 5. kilometers

Which of the following do you think would be the best unit of measure to express the height of the Eiffel tower. 1. centimeters 2. nanometers 3. gigameters 4. meters 5. kilometers

Which of the following is an SI unit ? 1. km 2. ml 3. kg 4. mg 5. cm

Which of the following is an SI unit ? 1. km 2. ml 3. kg 4. mg 5. cm