Chemistry HW questions
Express 1×10^−5 as an ordinary number. 0.00001 0.000001 0.001 0.0001
0.00001
Round off the following to three significant digits. 0.1085
0.109
2.90 cm × 0.2 cm
0.6cm^2
You call one of your friends to go to a movie on Friday night. He declines your invitation, stating that he needs to study for his upcoming exam on Monday. He states that he scores higher on a exam when he studies for the exam. Despite your efforts to convince him to go to the movie, he stays at home to study for his exam. You decide to use the scientific method to test the hypothesis that students who study for an exam tend to score higher than students who do not study for an exam. In what order should you conduct the following steps to test your hypothesis?
1.) design an experiment 2.) collect data 3.)analyze data 4.)confirm or revise hypothesis
Round off the following to three significant digits. 10850
1.09×104
Which of the following measurements corresponds to the graduated cylinder shown in the figure below having an uncertainty of ±0.05 mL? 1.9 mL 1.90 mL 1.950 mL 1.95 mL
1.90,1.95
Express 1×10^7 as an ordinary number. View Available Hint(s) 10,000,000 1,000,000 100,000,000 10,000
10,000,000
Round off the following to three significant digits. 10.20
10.2
Round off the following to three significant digits. 10.352
10.4
Subtract the following measurements and round off the answer: 19.50 cm− 8.9 cm 11 cm 10.60 cm 10.7 cm 10.6 cm
10.6 cm
Express 1×10^5 as an ordinary number. 10,000 100,000 1,000,000 0.1
100,000
10×10×10
10^3
1/10×1/10×1/10
10^−3
21.39cm−10.0cm =
11.4cm
5.67 cm × 2.0 cm
11cm^2
Suppose you are asked to find the area of a rectangle that is 2.1-cm wide by 5.6-cm long. Your calculator answer would be 11.76 cm2. Now suppose you are asked to enter the answer to two significant figures. (Note that if you do not round your answer to two significant figures, your answer will fall outside of the grading tolerance and be graded as incorrect.) Enter your answer to two significant figures and include the appropriate units.
12 cm^3
Multiply the following measurements and round off the answer: 6.25cm×2.05cm 13 cm2 213 cm 12.8 cm2 212.8 cm
12.8 cm2
20.4 cm^2 × 0.58 cm
12cm^3
13.5 cm^2 × 1.24 cm
16.7cm^3
State the number of significant digits in 7.0 cm. three significant digits two significant digits four significant digits one significant digit
2 significant digits
Round off 2.370×10^−4 to three significant digits. 2.38×10^−4 2.3×10^−4 2.37×10^−4 2.4×10^−4
2.37×10^−4
11.2 g /4.6 mL
2.4g/mL
5.3cm+ 16.1cm +0.56cm =
22.0cm
Which of the following measurements corresponds to the graduated cylinder shown in the figure below having an uncertainty of ±0.5 mL? 23.50 mL 23.0 mL 23 mL 23.5 mL
23.0, 23.5
48.820 g /13.0 mL
3.76g/mL
Multiply the following measurements and round off the answer: 18.50cm×2.1cm 39 cm 38.9 cm2 238.9 cm 39 cm2
39 cm2
Express the following ordinary number in scientific notation: 0.000 000 000 000 456 4.56×10^−12 0.456×10^−12 45.6×10^−14 4.56×10^−13
4.56×10^−13
Subtract the following measurements and round off the answer: 14.54 cm− 9.9 cm 5 cm 4.7 cm 4.64 cm 4.6 cm
4.6
1.68cm + 36.97cm+ 17.8cm =
56.5cm
Which of the following measurements corresponds to the graduated cylinder shown in the figure below having an uncertainty of ±0.1 mL? 6.10 mL 6.0 mL 6 mL 6.1 mL
6.0,6.1
Round off 6.614×10^8 to three significant digits. 6.6×10^8 6.7×10^8 6.61×10^8 6.62×10^8
6.61×10^8
93.135 g /14.00 mL
6.653g/mL
Express the following ordinary number in scientific notation: 7,250,000,000 72.5×10^7 0.725×10^9 7.25×10^7 7.25×10^9
7.25×10^9
57.8 g /7.9 mL
7.3g/mL
Round off the following to three significant digits. 7.842×10^12
7.84×1012
Multiply the following measurements and round off the answer: 2.95cm×2.70cm 7.97 cm 7.965 cm2 27.965 cm 7.97 cm2
7.97cm2
Using the correct answer from Part B, calculate the volume of a rectangular prism with a length of 5.6 cm, a width of 2.1 cm, and a height of 6.6 cm. Enter your answer to two significant figures and include the appropriate units.
78 cm^3
Round off the following to three significant digits. 7.852×10^3
7850
Round off the following to three significant digits. 8.0701×10^−8
8.07×10−8
Round off the following to three significant digits. 9.075×10^−12
9.08×10−12
Express the following ordinary number in scientific notation: 94,500,000,000,000,000 94.5×10^14 9.45×10^16 9.45×10^14 0.945×10^17
9.45×10^16
Round off 9.456×10^10 to three significant digits. 9.5×10^10 9.45×10^10 9.46×10^10 9.4×10^10
9.46×10^10
12.6cm−3.14cm =
9.5 cm
Subtract the following measurements and round off the answer: 11.0 cm− 1.34 cm 9.6 cm 9.7 cm 10 cm 9.66 cm
9.7
Scientific Method
A systematic investigation that involves performing an experiment, proposing a hypothesis, testing the hypothesis, and finally, stating a theory or law that explains a scientific principle.
Select all the industries in which chemistry plays an important role. Check all that apply. medicine petrochemical industry paper industry construction industry food industry
All of the above
Which of the following is a positive reason for learning chemistry? chemistry is relevant to daily life chemistry offers career opportunities chemistry studies interesting topics chemistry benefits society all of the above
All of the above
Chemistry has many applications to daily life. An example is the Hall-H´eroult process, in which the second most-used construction metal is produced. The metal is _____. A.)salt B.)aluminum C.)gold D.)iodine
Aluminum
Scientific theory
An extensively tested proposal of a scientific principle that explains the behavior of nature. A theory offers a model to describe nature; for example, the atomic theory describes the particle nature of matter.
Natural Law
An extensively tested proposal of a scientific principle that states a measurable relationship under different experimental conditions. A natural law is often expressed as an equation; for example, P1V1=P2V2P1V1=P2V2.
Hypothesis
An initial, tentative proposal of a scientific principle that attempts to explain the meaning of a set of data collected in an experiment.
Who is the founder of modern chemistry?
Antoine Lavoisier
The founder of modern chemistry is considered to be __________. A.)Antoine Lavoisier B.)Robert Boyle C.)Thomas Jefferson D.)Benjamin Franklin
Antoine Lavosier
Why is chemistry referred to as the central science? A.because it stands at the crossroads of biology, physics, geology, and medicine B.because it doesn't involve precise calculations C.because there are more chemists than physicists and mathematicians together D.because it's one of the oldest sciences E.because it is one of the youngest sciences
Because it stands at the crossroads of biology,physics,geology, and medicine
What is now known as the scientific method was first suggested by _____. A.)Thales B.)Aristotle C.)Boyle D.)Empedocles
Boyle
The study of the composition and properties of matter is known as _____. A.)physics B.)mathematics C.)biology D.)chemistry
Chemistry
Which of the following experiment setups would be the best way to test your hypothesis? A.) After the exam, give students a survey questioning their study habits and what grade they think they made on the exam. B.) Before the exam, give students a survey questioning their study habits. C.) Before the exam, give students a survey questioning their study habits and what grade they think they will make on the exam. D.) After the exam, give students a survey questioning their study habits and what grade they made on their exam.
D.) After the exam , give students a survey questioning their study habits and what grade they made on their exam
Early chemists (prior to the mid-1600s) included all of the following except _____. A.)Empedocles B.)Aristotle C.)Thales D.)Boyle
D.) Boyle
Which statement about the early history (pre-1600s) of chemistry is correct? A.)The four commonly accepted elements in early chemistry were water, earth, fire, and carbon dioxide. B.)Ancient Greek scientists were not aware that different forms of matter had different densities. C.)The earliest scientific study began in Western civilizations D.)Most of what we know now in the field of chemistry was "discovered" after the early 1600s.
D.) Most of what we know now in the field of chemistry was "discovered"
Who first published the periodic table? A.)Antoine Lavoisier B.)John Dalton C.)Robert Boyle D.)Dmitri Mendeleev C.)Johannes Nicolaus Brønsted
Dmitri Mendeleev
In which of the following industries does chemistry play an important role? A.)medicine B.)pharmaceutical C.)petrochemical D.)agriculture E.)all of the above
E.) All of the above
According to Aristotle's beliefs, what fifth element in addition to four basic elements is filling all space? A.)ether B.)air C.)good D.)god
Ether
The founder of medicine is _____. A.)Hippocrates B.)Thales C.)Lavoisier D.)Boyle
Hippocrates
A tentative explanation of a problem or a tentative statement of a scientific principle is a(n) _____. A.)theory B.)experiment C.)law D.)hypothesis
Hypothesis
What quantity (length, mass, volume, time) is expressed by the following units? ton
Mass
The volumes of two gases combine in the ratio of small whole numbers. scientific theory or natural law
Natural law
Who is considered the founder of the scientific method? A.)Dmitri Mendeleev B.)Johannes Nicolaus Brønsted C.)Robert Boyle D.)Antoine Lavoisier E.)John Dalton
Robert Boyle
The region surrounding the nucleus has negative charges. natural law or scientific theory
Scientific theory
When we drop an ice cube into water the transfer of heat is due to changes in the motion of molecules in the ice and water. scientific theory or natural law
Scientific theory
Organic Chemistry
The branch of chemistry that studies substances containing the element carbon
Biochemistry
The branch of chemistry that studies substances derived from plants and animals
Science
The methodical exploration of nature and the logical explanation of the observations.
Inorganic Chemistry
The study of all other substances, those that do not contain the element carbon
What quantity (length, mass, volume, time) is expressed by the following units? microsecond
Time
An example of a theory is modern atomic theory, which states that all matter is composed of small particles called atoms. Based on what you know about scientific theories in general, classify the following statements regarding modern atomic theory as true or false.
True: It is subject to experimentation and revision. It is supported by data. It is currently accepted as the most plausible explanation for the law of conservation of mass. False: It is the only possible explanation for the law of conservation of mass. It proves the existence of atoms. It is mere speculation.
An example of a scientific law is the law of conservation of mass, which states that matter is neither created nor destroyed in a chemical reaction. Based on what you know about scientific laws in general, classify the following statements regarding the law of conservation of mass as true or false.
True: It was developed from past observations. It is subject to experimentation and revision. It predicts future observations. False: It explains why mass is conserved.
What quantity (length, mass, volume, time) is expressed by the following units? cubic centimeter
Volume
According to ancient Chinese beliefs, what two forces were responsible for bringing the earthly world into existence?
Yin and Yang
What is the difference between a hypothesis and a theory? A.a hypothesis is an initial proposal that is tentative, whereas a theory is a proposal that has been tested extensively A.a hypothesis is a conclusion made after a theory was tested C.a hypothesis is a proposal that has been tested extensively, whereas a theory is an initialy stated proposal D.words hypothesis and theory are synonyms
a hypothesis is an initial proposal that is tentative, whereas a theory is a proposal that has been tested extensively
Alchemy
a pseudoscience that attempted to convert a base metal, such as lead, to gold; a medieval science that sought to discover a universal cure for disease and a magic potion for immortality
Green Chemistry
also termed sustainable chemistry, refers to the design of chemical products and processes that reduce or eliminate hazardous substances.
Why is chemistry referred to as the central science?
because it supports other physical sciences, life sciences, and earth sciences. An understanding of chemistry is also prerequisite to the health sciences.
According to the Greek philosopher Empedocles in 450 B.C., what four basic elements composed everything in nature? Check all that apply. A.)fire B.)heat C.)ether D.)air E.)earth F.)water
fire, air, earth,water
According to the Greek philosopher Aristotle in 350 B.C., what five basic elements composed everything in nature? Check all that apply. A.)air B.)fire C.)heat D.)earth E.)ether F.)water
fire, air, earth,water, ether
State the number of significant digits in 6.185 g. three significant digits two significant digits four significant digits one significant digit
four significant digits
What quantity (length, mass, volume, time) is expressed by the following units? nanometer
length
If the temperature of a gas doubles, the volume doubles. natural law or scientific theory
natural law
The total mass of reacting substances remains constant after reaction. natural law or scientific theory
natural law
Petrochemicals are derived from which of the following resources? atmosphere petroleum seawater trees none of the above
petroleum
The nucleus of an atom contains positive charges. scientific theory or natural law
scientific theory
The total energy of two gas molecules remains constant after colliding. scientific theory or natural law
scientific theory
The universe is expanding all the time. natural law or scientific theory
scientific theory
Chemistry
the science that studies the composition of matter and its properties.
What is the difference between a scientific theory and a natural law? A.theory explains the behavior of nature using a model or concept; whereas, a natural law states a relationship that is measurable under various experimental conditions B.expressions theory and natural law are synonyms C.theory and natural law essentially the same except that theories were created by human beings D.theory states a relationship that is measurable under various experimental conditions; whereas, a natural law explains the behavior of nature using a model or concept
theory explains the behavior of nature using a model or concept; whereas, a natural law states a relationship that is measurable under various experimental conditions
State the number of significant digits in 5.50×10−1 mL. three significant digits one significant digit two significant digits four significant digits
three significant digits
What is the second step in the scientific method? A.to plan and perform an experiment, then make observations and record data B.to conduct additional experiments in order to confirm the theory which was created on the first step C.to conduct additional experiments in order to test the hypothesis D.to analyze the data, and propose a tentative hypothesis to explain the experimental observations. E.to analyze the data, and create a theory to confirm the experimental observations
to analyze the data, and propose a tentative hypothesis to explain the experimental observations.
What is the third step in the scientific method? A.to plan and perform an experiment, then make observations and record data B.to create the final theory that wasn't denied by the second step's experiment C.to conduct additional experiments in order to test the hypothesis D.to analyze the data, and propose a tentative hypothesis to explain the experimental observations E.to conduct additional experiments in order to confirm the theory being created on previous step
to conduct additional experiments in order to test the hypothesis
What is the first step in the scientific method? A.)to collect and analyze the data and then perform an experiment to confirm the data being collected B.)propose a tentative hypothesis to explain the experimental observations made by other scientists C.)to plan and perform an experiment, then make observations and record data D.)to conduct additional experiments in order to test the hypothesis E.)to analyze the data, and propose a tentative hypothesis to explain the experimental observations
to plan and perform an experiment, then make observations and record data
Select all professions that require a training in chemistry. Check all that apply. builder cook veterinarians chiropractors pharmaceutist doctors physical therapists
veterinarians chiropractors pharmaceutist doctors physical therapists
According to the Greek philosopher Thales in 600 B.C., what single element composed Earth, air, and space? A.)fire B.)earth C.)water D.)ether E.)air
water
