Exam 1 HW questions

Indicate with a plus sign (+) any of these processes that require energy, and a negative sign (-) any that release energy. arctic ice melting

+

Indicate with a plus sign (+) any of these processes that require energy, and a negative sign (-) any that release energy. blowing up a balloon

+

Express each of the following numbers in exponential (scientific) notation. 2,900,000

2.9 x 10⁶

Enter the name and number of atoms of each element in each of the following compounds: Cu₃(PO₄)₂

Cu- Copper- 3 P- Phosphorus- 2 O- Oxygen- 8

A__________ is a tentative explanation of certain facts to provide a basis for further experimentation.

Hypothesis

Enter the name and number of atoms of each element in each of the following compounds: K₂CO₃

K- Potassium- 2 C- Carbon- 1 O- Oxygen- 3

Identify whether each of the following is a pure substance or a mixture: Carbon Dioxide

Pure Substance

It has a definite shape Gas Solid Liquid

Solid

Which is an observation? Water is colorless. Atoms consist of protons, neutrons, and electrons. Atoms can form chemical bonds by sharing electrons. All matter is composed of atoms.

Water is colorless.

Indicate with a plus sign (+) any of these processes that require energy, and a negative sign (-) any that release energy. dry ice changing to vapor

+

Complete the following metric conversions using the correct number of significant figures.Enter your answer in decimal form unless otherwise specified. Do not forget to put zero before decimal point if your answer is less than 1. 3.22 g to kg

0.00322 kg

Complete the following metric conversions using the correct number of significant figures.Enter your answer in decimal form unless otherwise specified. Do not forget to put zero before decimal point if your answer is less than 1. 1354 m to km

1.354 km

How many significant figures are in each of the following numbers? 0.03258

4

How many significant figures are in each of the following numbers? 0.08249

4

Complete the following metric conversions using the correct number of significant figures.Enter your answer in decimal form unless otherwise specified. Do not forget to put zero before decimal point if your answer is less than 1. 51.47 g to mg

5.147 x 10⁴ mg

Complete the following metric conversions using the correct number of significant figures.Enter your answer in decimal form unless otherwise specified. Do not forget to put zero before decimal point if your answer is less than 1. 5.2 x 10⁴ mg to kg

5.2 x 10⁻² kg

How many significant figures are in each of the following numbers? 1.34198 x 10³

6

What is the formula for density?

Density = mass/volume

Identify whether the following pure substance is an element or a compound. Zinc

Element

Mustard Flour Pure Substance Mixture

Mixture

Enter the name and number of atoms of each element in each of the following compounds: Na₂Cr₂O₇

Na- Sodium- 2 Cr- Chromium- 2 O- Oxygen- 7

The air feels cool. Observation Hypothesis Theory Scientific Law

Observation

Determine whether each of the following represents a physical property or a chemical property: Mercury is a liquid at 25°C

Physical

Determine whether each of the following represents a physical property or a chemical property: Sodium chloride is a crystalline solid

Physical

Determine whether each of the following represents a physical property or a chemical property: Sulfur is a bright yellow

Physical

Determine whether each of the following represents a physical property or a chemical property: Vinegar has a pungent odor

Physical

Are the following examples of potential energy or kinetic energy? a person napping

Potential

Are the following examples of potential energy or kinetic energy? sodium hydroxide in a sealed jar

Potential

The battery in the phone has a limited charge time and needs to be recharged on a regular basis in order to keep it in working order. Observation Hypothesis Theory Experiment

Theory

Which of the following is a pure substance existing as different phases in a heterogeneous system? cork floating in water ice floating in water salt dissolved in water flour suspended in water

ice floating in water

Enter the name and number of atoms of each element in each of the following compounds: Fe₂O₃

Fe- Iron- 2 O- Oxygen- 3

It has an indefinite volume and high compressibility Gas Solid Liquid

Gas

I think that the battery needs to be recharged Observation Hypothesis Theory Experiment

Hypothesis

My computer must have a virus since it is not working properly. Observation Hypothesis Theory Scientific Law

Hypothesis

The battery in my watch must be dead since it is no longer keeping time Observation Hypothesis Theory Scientific Law

Hypothesis

These formulas look similar but represent different things. 8S and S₈ Compare and contrast them. How are they different? In 8S the atoms are____. In S₈ the atoms are____. Joined as a unit (molecule) Separate and distinct

In 8S the atoms are separate and distinct. In S₈ the atoms are joined as a unit (molecule)

Indicate with a plus sign (+) any of these processes that require energy, and a negative sign (-) any that release energy. starting a car

+

Indicate with a plus sign (+) any of these processes that require energy, and a negative sign (-) any that release energy. flash of lightning

-

Solve the following problems, stating answers to the proper number of significant figures. Use scientific notation when it is indicated for the answers. (0.0239)(12.0)

0.287

Complete the following metric conversions using the correct number of significant figures.Enter your answer in decimal form unless otherwise specified. Do not forget to put zero before decimal point if your answer is less than 1. 28.9 cm to m

0.289 m

The formula for vitamin B₁₂ is C₆₃H₈₈CoN₁₄O₁₄P. What fraction of the total atoms are metallic?

1/181

Solve the following problems, stating answers to the proper number of significant figures. Use scientific notation when it is indicated for the answers. 10.49 + 3.0 + 0.091

13.6

The formula for vitamin B₁₂ is C₆₃H₈₈CoN₁₄O₁₄P. How many atoms make up one molecule of vitamin B₁₂?

181

Solve the following problems, stating answers to the proper number of significant figures. Use scientific notation when it is indicated for the answers. (462 x 5.9)/(13.6)

2.0 x 10²

Solve the following problems, stating answers to the proper number of significant figures. Use scientific notation when it is indicated for the answers. 10.0 + 2.84(1.1 x 10⁴)

3.1 x 10⁴

Solve the following problems, stating answers to the proper number of significant figures. Use scientific notation when it is indicated for the answers. (4.14 x 10³)(7.60 x 10⁴)

3.15 x 10⁸

Complete the following metric conversions using the correct number of significant figures.Enter your answer in decimal form unless otherwise specified. Do not forget to put zero before decimal point if your answer is less than 1. 32.3 L to μL

3.27 x 10⁷ μL *μ= micro

Complete the following metric conversions using the correct number of significant figures.Enter your answer in decimal form unless otherwise specified. Do not forget to put zero before decimal point if your answer is less than 1. 38.8 mL to L

3.88 x 10⁻² L

The formula for vitamin B₁₂ is C₆₃H₈₈CoN₁₄O₁₄P. What percentage of the total atoms are carbon?

35%

Complete the following metric conversions using the correct number of significant figures.Enter your answer in decimal form unless otherwise specified. Do not forget to put zero before decimal point if your answer is less than 1. 4.37 cm to mm

43.7 mm

Express each of the following numbers in exponential (scientific) notation. 0.0000055

5.5 x 10⁻⁶

Express each of the following numbers in exponential (scientific) notation. 0.587

5.87 x 10⁻¹

How many significant figures are in each of the following numbers? 38.0647

6

Express each of the following numbers in exponential (scientific) notation. 0.00840

8.40 x 10⁻³

Solve the following problems, stating answers to the proper number of significant figures. Use scientific notation when it is indicated for the answers. (0.4951)/(54.0)

9.17 x 10^⁻³

Absent-minded Alfred put down a bottle containing silver on the table. When he went to retrieve it, he realized he had forgotten to label the bottle. Unfortunately, there were two full bottles of the same size side-by-side. Alfred realized he had placed a bottle of mercury on the same table last week. State the ways Alfred can determine which bottle contains silver without opening the bottles. -The bottle of silver weighs more than the bottle of mercury. -Silver is darker than mercury. -The bottle of mercury weighs more than the bottle of silver. -Silver is solid, mercury is liquid. -Mercury is darker than silver. -Mercury is solid, silver is liquid.

???

During the first week of a new semester, consider that you have enrolled in five different classes, each of which meets for 3 hours per week. For every 1 hour that is spent in class, a minimum of 1 hour is required outside of class to complete assignments and study for exams. You also work 20 hours per week, and it takes you 1 hour to drive to the job site and back home. On Friday nights, you socialize with your friends. You are fairly certain that you will be able to successfully complete the semester with good grades. Show how the steps in the scientific method can help you predict the outcome of the semester. Match each of the following statements concerning your semester with the correct step of the scientific method: A. In the first two weeks of the semester keep a record of your performance in each class, including grades on homework, quizzes and exams. B. This includes the number of classes you have enrolled in, the amount of time you will give to each class, the number of hours required for your off campus job, and the amount of time for social activities. C. If your grades in any class are not good, your idea was incorrect. It will be necessary to increase the amount of time allocated to that class. D. You predict the amount of time you have allocated each week for class work will be sufficient to result in good grades at the end of the semester. 3. Plan and do additional experiments to test the hypothesis. ___

A. In the first two weeks of the semester keep a record of your performance in each class, including grades on homework, quizzes and exams.

During the first week of a new semester, consider that you have enrolled in five different classes, each of which meets for 3 hours per week. For every 1 hour that is spent in class, a minimum of 1 hour is required outside of class to complete assignments and study for exams. You also work 20 hours per week, and it takes you 1 hour to drive to the job site and back home. On Friday nights, you socialize with your friends. You are fairly certain that you will be able to successfully complete the semester with good grades. Show how the steps in the scientific method can help you predict the outcome of the semester. Match each of the following statements concerning your semester with the correct step of the scientific method: A. In the first two weeks of the semester keep a record of your performance in each class, including grades on homework, quizzes and exams. B. This includes the number of classes you have enrolled in, the amount of time you will give to each class, the number of hours required for your off campus job, and the amount of time for social activities. C. If your grades in any class are not good, your idea was incorrect. It will be necessary to increase the amount of time allocated to that class. D. You predict the amount of time you have allocated each week for class work will be sufficient to result in good grades at the end of the semester. 1. Collect the facts or data. ____

B. This includes the number of classes you have enrolled in, the amount of time you will give to each class, the number of hours required for your off campus job, and the amount of time for social activities.

Enter the name and number of atoms of each element in each of the following compounds: C₂H₅OH

C- Carbon- 2 H- Hydrogen- 6 O- Oxygen- 1

Enter the name and number of atoms of each element in each of the following compounds: CH₃COCH₃

C- Carbon- 3 H- Hydrogen- 6 O- Oxygen- 1

During the first week of a new semester, consider that you have enrolled in five different classes, each of which meets for 3 hours per week. For every 1 hour that is spent in class, a minimum of 1 hour is required outside of class to complete assignments and study for exams. You also work 20 hours per week, and it takes you 1 hour to drive to the job site and back home. On Friday nights, you socialize with your friends. You are fairly certain that you will be able to successfully complete the semester with good grades. Show how the steps in the scientific method can help you predict the outcome of the semester. Match each of the following statements concerning your semester with the correct step of the scientific method: A. In the first two weeks of the semester keep a record of your performance in each class, including grades on homework, quizzes and exams. B. This includes the number of classes you have enrolled in, the amount of time you will give to each class, the number of hours required for your off campus job, and the amount of time for social activities. C. If your grades in any class are not good, your idea was incorrect. It will be necessary to increase the amount of time allocated to that class. D. You predict the amount of time you have allocated each week for class work will be sufficient to result in good grades at the end of the semester. 4. Modify the hypothesis. ___

C. If your grades in any class are not good, your idea was incorrect. It will be necessary to increase the amount of time allocated to that class.

Enter the name and number of atoms of each element in each of the following compounds: Ca(NO₃)₂

Ca- Calcium- 1 N- Nitrogen- 2 O- Oxygen- 6

Determine whether each of the following represents a physical property or a chemical property: Aluminum combines with oxygen to form a protective oxide coating

Chemical

Determine whether each of the following represents a physical property or a chemical property: Carbon cannot be decomposed

Chemical

Determine whether each of the following represents a physical property or a chemical property: Oxygen is not combustible

Chemical

Determine whether each of the following represents a physical property or a chemical property: Water does not burn

Chemical

State whether each of the following represents a chemical change or merely a physical change: A steak is cooked on a grill until well done

Chemical

State whether each of the following represents a chemical change or merely a physical change: Chlorine bleach is used to remove a coffee stain on a white lab coat

Chemical

State whether each of the following represents a chemical change or merely a physical change: One gram of an orange crystalline solid is heated in a test tube, producing a green powdery solid whose volume is 10 times the volume of the original substance

Chemical

State whether each of the following represents a chemical change or merely a physical change: When two clear and colorless aqueous salt solutions are mixed together, the solution turns cloudy and yellow

Chemical

Enter the name and number of atoms of each element in each of the following compounds: Co(C₂H₃O₂)₂

Co- Cobalt- 1 C- Carbon- 4 H- Hydrogen- 6 O- Oxygen- 4

During the first week of a new semester, consider that you have enrolled in five different classes, each of which meets for 3 hours per week. For every 1 hour that is spent in class, a minimum of 1 hour is required outside of class to complete assignments and study for exams. You also work 20 hours per week, and it takes you 1 hour to drive to the job site and back home. On Friday nights, you socialize with your friends. You are fairly certain that you will be able to successfully complete the semester with good grades. Show how the steps in the scientific method can help you predict the outcome of the semester. Match each of the following statements concerning your semester with the correct step of the scientific method: A. In the first two weeks of the semester keep a record of your performance in each class, including grades on homework, quizzes and exams. B. This includes the number of classes you have enrolled in, the amount of time you will give to each class, the number of hours required for your off campus job, and the amount of time for social activities. C. If your grades in any class are not good, your idea was incorrect. It will be necessary to increase the amount of time allocated to that class. D. You predict the amount of time you have allocated each week for class work will be sufficient to result in good grades at the end of the semester. 2. Formulate a hypothesis. ___

D. You predict the amount of time you have allocated each week for class work will be sufficient to result in good grades at the end of the semester.

These formulas look similar but represent different things. 8S and S₈ Compare and contrast them. How are they alike? Each is one compound. Each is multiple discrete individual units. Each represents eight atoms of sulfur. There are no similarities.

Each represents eight atoms of sulfur.

Plug in the phone to recharge the battery and allow sufficient time for the battery to fully recharge. Turn the phone back on. The phone now works again Observation Hypothesis Theory Experiment

Experiment

Are the following examples of potential energy or kinetic energy? a bird flying

Kinetic

Are the following examples of potential energy or kinetic energy? fan blades spinning

Kinetic

Are the following examples of potential energy or kinetic energy? ocean waves rippling

Kinetic

It has a definite volume, but not a definite shape Gas Solid Liquid

Liquid

It has an indefinite shape and slight compressibility Gas Solid Liquid

Liquid

Chicken Broth Pure Substance Mixture

Mixture

Identify whether each of the following is a pure substance or a mixture: Beach Sand

Mixture

Identify whether each of the following is a pure substance or a mixture: Cement

Mixture

Identify whether each of the following is a pure substance or a mixture: Hot tea

Mixture

Identify whether each of the following is a pure substance or a mixture: Vinegar

Mixture

My cell phone has stopped working Observation Hypothesis Theory Experiment

Observation

My sister wears red quite often. Observation Hypothesis Theory Scientific Law

Observation

Which matter contains the least force of attraction between particles? Mercury Sodium metal Liquid bromine Oxygen gas

Oxygen gas

Which of the following are diatomic molecules? O₂ N₂O ClF P₄ HCl SiO₂ CH₄ H₂O₂

O₂ ClF HCl

State whether each of the following represents a chemical change or merely a physical change: In the lab, a student cuts a 20 cm strip of magnesium metal into 1-cm pieces

Physical

State whether each of the following represents a chemical change or merely a physical change: In the lab, students firepolish the end of a glass rod. The jagged edge of the glass has become smooth

Physical

Identify whether each of the following is a pure substance or a mixture: Zinc

Pure Substance

Salt Pure Substance Mixture

Pure Substance

Water Pure Substance Mixture

Pure Substance

A ______________ is a simple statement of natural phenomena to which no exceptions are known under the given conditions.

Scientific Law

A pure substance has a definite, fixed composition. Observation Hypothesis Theory Scientific Law

Scientific Law

Which of the following are pure substances? Sand Sugar Gold Maple Syrup Eggs

Sugar Gold

Your boss found a piece of metal in the lab and wants you to determine what the metal is. She is pretty sure that the metal is either lead, aluminum or silver. The lab bench has a balance and a 100-mL graduated cylinder with 50 mL of water in it. You decide to weigh the metal and find that it has a mass of 20.25 g. After dropping the piece of metal into the graduated cylinder containing water you observe that the volume increased to 57.5 mL. Identify the metal. The unknown metal is silver. The unknown metal is lead. The unknown metal is aluminum.

The unknown metal is aluminum.

A______ is an explanation of the general principles of certain phenomena with considerable evidence to support it.

Theory

The candle burns more brightly in pure oxygen than in air because oxygen supports combustion. Observation Hypothesis Theory Scientific Law

Theory