5. CHEMISTRY REVIEW

ELEMENTS, COMPOUNDS, AND MIXTURES

----

GASES AND MOLES

----

MEASUREMENT AND ANALYSIS

----

QUIZ 1: MEASUREMENT TO GASES AND MOLES

----

SCIENTIFIC ANALYSIS AND SIGNIFICANT FIGURES

----

125 K = °C

-148

5.00 g of magnesium represents how many moles? moles

0.206

A direct relationship can be represented by: y/x=k xy=k a curved line data

1

A theory that repeatedly fails to confirm the expected predictions: needs to be modified is probably correct requires more research time should be maintained indefinitely

1

Assuming the volume of the insoluble substance to be 92.5 mL and the mass to be 693.8 g, what is the density of the substance? Be sure to use the correct number of significant figures. 7.50 g/mL 7.500 g/mL 0.133 g/mL 0.1333 g/mL

1

Express the answer in scientific notation & observe significant figure rules. (1.8 x 10-2) ÷ (9 x 102) 2 x 10-5 0.2 x 10-4 0.20 x 10-4 2.0 x 10-5

1

Initial ideas that are believed to be true and from which a person begins to reason are called: presuppositions theories laws hypotheses

1

Read this balance. 206.50 g 265.0 g 206.5 g

1

Scientific predictions should be made from: deductive reasoning inductive reasoning presuppositions subjective reasoning

1

When an explanation to a problem is accepted as always true, it is a: law theory hypothesis fact

1

Which of these is an appropriate instrument to measure mass? balance scale ruler graduated cylinder

1

Select all that apply. A direct relationship occurs when: two variables increase at the same time two variables decrease at the same time one variable increases as another variable decreases xy=k

1 2

A scientific law: (Select all that apply.) is generally accepted as true has never been found to be in error has no known contradictions must be reverified occasionally

1 2 3

Select all that apply. Which of the following measurements have 1 significant figure? 0.007 7000 7000.0 7

1 2 4

Select all that apply. 1,670 cm3 = _____ 1,670 mL 1,670 kg 1.67 L 1.67 g

1 3

Select all that apply. Which of the following measurements have 3 significant figures? 0.0882 m 0.8820 m 8,820 m 882.0 m

1 3

is defined as the direct relationship between temperature and volume of gases such that as temperature (absolute scale) increases, volume increases by the same fraction of change.

Charles law

0.000626 L is the same as 6.26 cm3. True False

F

0.00726 g is the same as 0.726 mg. True False

F

Density is a chemical property. True False

F

Density is inversely proportional to pressure. True False

F

On the periodic table, elements are arranged according to their mass numbers. True False

F

Solution particles will eventually settle out. True False

F

A 25-liter sample of steam at 100.0°C and 1 atm is cooled to 25.0°C and expanded until the pressure is 20.0 mm Hg. If no water condenses, calculate the final volume of the water vapor. V2 = _____ L 1.0 273 240 760

4

A scientist wished to carry out a chemical reaction in which two moles of aluminum combine with three moles of sulfur. He has 2.70 g of aluminum to react. How many grams of sulfur must he use to satisfy all the aluminum atoms? 1.51 g 2.14 g 3.41 g 4.81 g

4

Compounds that are found naturally in the earth are called: ores composites rocks minerals

4

Define volume. the mass of liquid required to fill a container length x width x height the space occupied by a liquid the space occupied by a quantity of matter

4

Solve the following mole-mass problem. Refer to the periodic table. How much mass does 0.1 mole of neon contain? 26.018 g 2.02 g 2.0 g 2 g

4

Solve the following mole-mass problem. Refer to the periodic table. How much mass does 0.50 mole of copper contain? 31.775 g 31.78 g 31.8 g 32 g

4

Which of the following is not equal to 0.0326 kilometers? 3.260 dkm 32.6 m 3,260 cm 326,000 mm

4

Which of the following measurements has 2 significant figures? 0.001 cm 11.0 cm 100 cm 100 cm

4

Which of the following measurements has 4 significant figures? 832,000 g 8000 g 800. g 800.0 g

4

Round 6.362 to 2 significant digits:

6.4

The number 89.667 rounded off to three significant figures is

89.7

Which balance is the centigram balance? A B

B

A gas occupies 200 mL at -73.0°C. To have the same gas occupy 300 mL, should the temperature be increased or decreased? What is the new temperature in Kelvins? K

increased 300

Forming a hypothesis is accomplished through reasoning.

inductive

The rocks and minerals of the earth consist of compounds.

inorganic

The biosphere of the earth is made up of compounds.

organic

An excellent tool to gauge the reliability of any theory is its capacity to generate accurate

predictions

A mixture in which the particles eventually settle out is called a .

suspension

A hypothesis which appears to be verified by multiple experiments and/or researchers may become a .

theory

The scattering of light by a colloid is called the .

tyndall effect

The various components of a mixture do not combine chemically. True False

T

Match each word with its definition. Match the items in the left column to the items in the right column. 1. a hypothesis that equal volumes of gas under equal conditions have equal numbers of molecules 2. the number of particles in a mole of a substance; equals 6.02 x 1023 particles per mole 3. the inverse relationship such that as pressure increases, volume decreases 4. the direct relationship such that as temperature increases, volume increases 5.a law derived from combining Boyle's and Charles's Laws 6. the process of intermingling molecules from one substance into another by random motion 7. the symbolic representation of a chemical reaction based on the conservation of mass 8. the energy of motion which is represented as K.E. = 1/2 mv2 9. theory that all matter is particulate, in continuous motion, and increasingly spread out from solids to gases 10. one atomic weight of an atom or molecular weight of a molecule expressed in grams 11. the substance yielded as a result of a chemical reaction 12. one of the starting substances (ingredients) in a chemical reaction

1. Avogadro's Hypothesis 2. Avogradro's Number 3. Boyle's Law 4. Charles' Law 5.Combined gas Law 6.diffusion 7. equation 8. kinetic energy 9. Kinetic Molecular Theory 10. mole 11. product 12. reactant

Match the common elements with their symbols. 1. magnesium 2. potassium 3. iron 4. lead

1. Mg 2. K 3. Fe 4. Pb

Match the following words. Match the items in the left column to the items in the right column. 1. the correctness of measurement 2. the measure of the distance from one point to another 3. a measure of the quantity of matter in an object 4. how spread out the results of an experiment are or how repeatable measurements are; often dependent on the certainty with which an estimation can be made 5. space occupied by a quantity of matter

1. accuracy 2. length 3. mass 4. precision 5. volume

Match each word with its definition. Match the items in the left column to the items in the right column. 1. the simplest unit of an element that still retains the properties of that element 2.a group of elements that generally give up electrons 3. a primary substance that cannot be divided into separate substances 4. composed of dissimilar parts which can be separated easily 5. even distribution of parts throughout the whole mixture 6. compounds that do not contain the element carbon 7. a change from one state of matter to another 8. a change in shape, size, or physical characteristics while remaining the same substance

1. atom 2. metal 3. element 4. heterogeneous 5. homogeneous 6. inorganic 7. phase change 8. physical change

Match each word with its definition. Match the items in the left column to the items in the right column. 1. a uniform dispersion, heterogeneous in nature, between two or more substances 2. the group of elements that are good conductors of electricity and heat; solids except for mercury 3. two or more substances dispersed in one another but each retaining their own identity 4.the group of elements that are poor conductors of electricity and heat; mostly liquids and gases 5. two or more elements joined together such that the elements have lost their individual identities

1. colloid 2. metal 3. mixture 4. nonmetal 5. compound

Match the following. Match the items in the left column to the items in the right column. 1. a prediction made or conclusion drawn from insight gained from an established principle 2. when two variables change in the same direction, one remaining larger than the other by the same factor 3. an initial proposed explanation for a phenomenon 4. when one variable becomes larger and the other variable becomes smaller by the same factor 5. a relationship that is accepted as true and no longer needs to be tested and verified 6. real reasoning based on data or facts 7. initial idea which is believed to be true 8. a generalized model used to explain observations

1. deductive reasoning 2. direct relationship 3. hypothesis 4. inverse relationship 5. law 6. objective 7.presupposition 8. theory

Match the three phases of matter. 1. fixed volume; variable shape 2. fixed volume; fixed shape 3. variable volume; variable shape

1. liquid 2. solid 3. gas

A solution that contains maximum solute at a given temperature is: condensed saturated super-saturated an electrolyte

2

A substance made up of all identical atoms is: a chemical an element compound alloy

2

An inverse relationship can be represented by: y/x-k xy=k a straight line data

2

An unknown insoluble substance displaced the water shown. Its mass is indicated on the triple beam balance. volume of water displaced = _____ 92 92.5 92.50

2

Express as an ordinary number. 8.97 x 10-3 = _____ 0.0897 0.00897 0.000897 0.0000897

2

Measure the length of the line within the amount of uncertainty. 13 mm 21.5 mm 22 mm 21 mm

2

Read the following graduated cylinder. 22 mL 22.5 mL 22.50 mL

2

Read the following graduated cylinder. 47 mL 47.2 mL 47.25 mL

2

The Kinetic Molecular Theory helps explain relationships: between gravity, temperature, and nuclear forces between atoms, energy, temperature, and phases of conversion of mass to energy to mass of energy conversion between kinetic and potential energy all of the above

2

The Law of Conservation of Mass states the mass of the products must be ____ the mass of the reactants in any chemical reaction greater than equal to less than

2

The unknown sample has a mass of: 91.490 g 90.495 g 49.49 g 94.988 g 94.48 g

2

What is the length of the object shown? 9.8 cm 9.77 cm 9.771 cm

2

What is the smallest division written on the balance? 1 g 0.1 g 0.01 g 0.001 g

2

Which of the following is not equal to 0.005 meters? 0.000005 km 50 mm 0.0005 dkm 0.5 cm

2

Which of the following is not equal to 0.35 centimeters? 0.0000035 km 0.00035 hm 0.0035 m 3.5 mm

2

Which of the following is not equal to 11.6 millimeters? 0.0000116 km 0.00116 m 0.116 dm 1.16 cm

2

Which of the following is not equal to 63 meters? 0.063 km 0.63 dkm 6,300 cm 63,000 mm

2

Which temperature conversion is correct? °C = K + 273 °C = K - 273 K = °C - 273 K = 273 x °C

2

Which properties are characteristic of true solutions? (Select all that apply.) The particles are suspended indefinitely. The particles are dissolved. The particles are larger than 10-8 cm. The light beam is unaffected.

2 4

Round 23.455 to 4 significant digits:

23.46

An unknown insoluble substance displaced the water shown. Its mass is indicated on the triple beam balance. mass = _____ 694 693.5 693.8 693.80

3

Descriptions based on measurements or reasoning free of bias are: deductive subjective objective inductive

3

Express as an ordinary number. 3.4 x 104 = _____ 340 3,400 34,000 340,000

3

Express in scientific notation. 0.000543 = _____ 5.43 x 10-2 5.43 x 10-3 5.43 x 10-4 5.43 x 10-5

3

Hardness is indirectly related to: specific gravity surface roughness strength of chemical bonds weight

3

How many liters are in a cubic meter? 10 100 1,000 10,000 100,000

3

Read the following graduated cylinder to the correct precision. 13 mL 12.8 mL 12.80 mL 12.799 mL

3

Read the following graduated cylinder to the correct precision. 45 mL 47.5 mL 47.2 mL 47.20 mL

3

The size of the chosen symbols on a graph may be used to indicate the: location of the data coordinates of the data uncertainty of the data relationship of the variables

3

The substance that is dissolved in a solution is called a: solvent colloid solute precipitant

3

What are the foundations of beliefs from which a person begins to reason called? theory hypothesis presupposition none of the above

3

What is the smallest division that you should record for measurements using this balance? 1 g 0.1 g 0.01 g 0.001 g

3

Which is the correct measure of density? 1. cm3/g 2. mass*volume 3. g/cm3 4. g/m3

3

Which of the following is not equal to 42.7 millimeters? 0.0000427 km 0.000427 hm 0.00427 m 4.27 cm

3

Which one of the following is not equal to 72.6 grams? 0.0726 kg 72,600 mg 726 cg 0.726 hg

3

63°C = K

336

0.0155 kg is the same as 15,500 mg. True False

T

4.75 mL is the same as 0.00475 L. True False

T

8,740 cm3 is the same as 8.74 L. True False

T

Temperature is a measure of the average kinetic energy of a gas. True False

T

The molecular weight of H2 and the mass of 1 mole of H2 are equal quantities. True False

T

Balance the following equation by adding the correct mole numbers. P4 + Cl2 → PCl3

blank 6 4

Assuming these numbers are measurements, how many significant figures are allowed in the answer to this multiplication problem? (2.4 x 109) (4.0 x 1023) 1 2 3

literally 2

Water boils at a temperature at a higher altitude than it does at sea level.

lower