化学
化学反应、化学计量、分子结构与元素性质。
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question 10 of 32 solution a has a ph of 7, and solution b has a ph of …
C. Solution B is basic, and solution A is neutral.
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question 7 of 11 select the extensive physical property. volume boiling…
A. volume
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how are the concentration of the reactants and reaction rate related? a…
C. A change in concentration results in a change in the rate of a reaction.
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question 8 of 32 some vitamins and dietary supplements are stored in op…
B. Catalyst
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what is the density of a slug of tin that weighs 32.0320 g and occupies…
\( 7.28 \)
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what is the value of the volume of the liquid in the graduated cylinder…
76
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question 7 of 32 what would happen if a small amount of acid were added…
A. The pH would remain about the same.
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question 6 of 32 which of the following combinations of compounds will …
B. $\ce{CH3COOH}$ and $\ce{NaCH3COO}$
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question 5 of 32 what is the equilibrium expression for the reaction be…
A. \(\frac{[\ce{NH3}]^2}{[\ce{N2}][\ce{H2}]^3}\)
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question 4 of 32 how would the graph below change if a catalyst were ad…
B. Part 2 would be lower, and parts 1 and 3 would be unchanged.
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question 3 of 32 how would the equilibrium of the reaction below be aff…
C. The concentrations of \( \ce{O_{2}} \) and \( \ce{SO_{2}} \) would increase.
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question 2 of 32 what are the products of the neutralization reaction b…
C. CaCl₂ and H₂O
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question 1 of 32 hydrogen and oxygen react to form water. which stateme…
B. The concentrations of water, oxygen, and hydrogen are stable.
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at room temperature (20 °c), liquid water has a density of 1.00 g/ml an…
First blank: is less dense than; Second blank: float
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carbon compounds quick check which structure defines the sulfhydryl fun…
A. SH
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carbon compounds quick check which type of bonds can carbon atoms form …
C. single, double, and triple bonds
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carbon compounds quick check which option describes the structure of th…
B. The inner shell is complete with two electrons. The outer shell is incomplete with four electrons.
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carbon compounds quick check why is carbon said to provide a \backbone\…
D. Carbon atoms can form chains and branches with each other, and other atoms can attach to these.
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question 29 of 30 what happens to ice as it melts? a. the released ener…
C. The absorbed energy breaks apart intermolecular forces.
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arrange the following substances from least dense to most dense. most d…
Least dense: methanol (\( d = 0.792 \, \text{g/mL} \)) → water (\( d = 0.998 \, \text{g/mL} \)) → magnesium (\( d = 1.74 \, \text{g/mL} \)) → iron (\( d = 7.87 \, \text{g/mL} \)) …
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question 28 of 30 how many moles of neon (ne) gas have a volume of 0.84…
D. 0.21 mol
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question 27 of 30 which method can be used to separate a mixture of eth…
C. Distillation
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question 27 of 30 which method can be used to separate a mixture of eth…
C. Distillation
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question 26 of 30 how do forces between particles in gases compare to f…
D. The forces in gases are weaker than forces in solids and liquids.
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question 25 of 30 when sugar is added to a sugar solution, the sugar di…
B. Unsaturated
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question 23 of 30 which statement best describes the intermolecular for…
B. Van der Waals forces are the strongest force between \( \ce{H_2} \) molecules, and hydrogen bonding is the strongest force between the \( \ce{NH_3} \) molecules.
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4. hearing protection should be worn anytime the noise level exceeds a.…
d. 90 dB ### Question 5
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question 22 of 30 with carbon dioxide, what phase change takes place wh…
C. A liquid changes to a solid.
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question 21 of 30 the partial pressures of the gases in a mixture are 0…
C. 2.76 atm
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question 20 of 30 which solution is an example of a nonelectrolyte? a. …
A. Iodine in hexane
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if an atom has 4 protons, 3 neutrons and 4 electrons, then this is an a…
beryllium (the option corresponding to beryllium, e.g., if the options are as given: the option with "beryllium")
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question 18 of 30 what is the change in the freezing point of water whe…
A. -0.634$^\circ$C
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central part of the atom containing protons and neutrons * 1 point drop…
atom
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question 17 of 30 what is the phase of water at 0.25 atm and 0°c? phase…
D. Solid
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question 16 of 30 what is the predicted change in the boiling point of …
C. \( 0.015^\circ C \)
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question 15 of 30 charless law describes the relationship of the volume…
C. The volume would be 3/4 of its original value.
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question 10 of 10 suppose a sample of water in this experiment had a ma…
### Conversion to pounds (lb) # Explanation: ## Step1: Identify conversion factor We know that \( 1\ \text{lb} = 454\ \text{g} \), so the conversion factor to convert grams to pou…
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question 13 of 30 in diamond, carbon atoms are bonded together by exten…
A. Network
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when your workplace obtains new materials, you should add them to the c…
C. Immediately
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the hazard communication standard requires employers to do all of the f…
A. Prepare and post a list of all employees who handle hazardous and toxic substances in the workplace
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suppose a buret was used to deliver 18.77 ml of water into a beaker. ex…
s: - \(18.77\space mL=\boldsymbol{0.01877}\space L\) - \(18.77\space mL=\boldsymbol{1.877\times 10^{4}}\space\mu L\) (If we consider the box with \(×10^{0}\), there might be a mis…
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question 10 5 points using your data table 1 step 2, from your procedur…
11.8 ### Question 11 (Note: Since no data table is provided, we can't calculate the exact values, but here's the method for each part): #### Part a: To find the initial volume of …
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question 11 of 30 avogadro’s law relates the volume of a gas to the num…
A. 4 moles gaseous product
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which of the following is a characteristic of solid silver? a. high ele…
A. High electrical conductivity
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what causes pressure inside an inflated soccer ball? a. the gas molecul…
C. The gas molecules move rapidly and collide with the surface of the ball.
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question 8 of 30 how can a mixture of salt and sand be separated? a. by…
C. By dissolving the salt in water and filtering out the sand
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question 8 of 10 a solution was prepared by adding 641 mg of sodium chl…
\(25.7\) (Wait, no, earlier calculation was 25.7282, and if we consider significant figures in the sum, maybe I made a mistake. Wait, 641 mg is 0.641 g (three sig figs), 72.2 mg i…
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the mass of a beaker was measured to be 125.445 g. a buret was used to …
\( 0.372 \)
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question 8 5 points using your data table 1, from your procedure docume…
4
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question 7 of 30 what is the pressure of 0.5 mol nitrogen (n₂) gas in a…
C. 1.7 atm
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question 6 using your data table 1, from your procedure document: input…
3
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question 6 of 30 a mixture of he, ne, and n₂ gases has a pressure of 1.…
A. 1.24 atm
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question 5 of 30 which substance will form a solution when mixed with s…
D. $\ce{CH_{3}OH}(l)$
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3. condensation is an exothermic process. this means that energy ______…
has been removed from a system
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question 6 of 10 perform the following calculations and report your ans…
First calculation: $\boxed{8.6}$ (wait, but earlier I thought 8.5557 rounded to two sig figs is 8.6? Wait, 8.5557: first two sig figs are 8 and 5. The next digit is 5, so we round…
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the cylinder shown at right, the correct volume is 56.0ml. data table e…
s for Part 2: a) $\boldsymbol{1547}$ (or $1.547\times 10^{3}$) milliliters b) $\boldsymbol{20.}$ (or $2.0\times 10^{1}$) inches c) $\boldsymbol{7666}$ (or $7.666\times 10^{3}$) gr…
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question 5 of 10 report the following values to the specified number of…
$0.00100$ ### 98289 reported to 2 significant figures:
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question 4 of 10 three groups of students were tasked with determining …
s: - Most accurate: Group 1 - Most precise: Group 2 (For the multiple-choice format: Which group was most accurate? \(\boldsymbol{\text{Group 1}}\) Which group was most precise? \…
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1. thermal energy is added to water. which of the following describes t…
Bonds have been broken that hold particles in place.
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if you wanted to measure the volume of a liquid to the greatest precisi…
D. buret (Note: Assuming the options are labeled as A: All of the glassware... , B: graduated cylinder, C: Erlenmeyer flask, D: buret, E: beaker. If the original labeling is diffe…
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classify the glassware used in this experiment based on the number of d…
- 0 decimal places: beaker, Erlenmeyer flask - 1 decimal place: graduated cylinder - 2 decimal places: buret - 3 decimal places: (No glassware from the answer bank)
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12. how are the codes (chemical formulas) for 13. use what you have jus…
To solve this, we recall the definitions: - **Element**: Consists of only one type of atom (chemical symbol of one element). - **Compound**: Consists of two or more different elem…
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7. appoint one group member to cut apart model 1 to separate the nine d…
To solve these questions, we analyze the definitions and apply them: ### Question 8 #### Brief Explanations: - **Pure Substances**: Drawings where all particles are identical (mat…
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steel is an example of a pure substance because it is made up of two di…
false ### Question 6 (Salt dissolving in water):
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question 4 (multiple choice worth 4 points) (01.06br mc) which of the f…
The particles have no set ratio for how to combine, and they can be separated by physical means.
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what type of solution contains more solute than would normally dissolve…
Supersaturated (the option corresponding to "Supersaturated")
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during an experiment, iron powder and sulfur powder were mixed thorough…
Iron powder and sulfur powder combined physically, therefore they retained their individual properties.
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part 2: what is whmis? workplace hazardous materials information system…
To solve this WHMIS (Workplace Hazardous Materials Information System) symbol - matching problem, we analyze each symbol, its name, and the safety implications: ### Symbol 1 (Expl…
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check for understanding use your understanding of density to complete t…
B. vegetable oil, 0.71 g/mL ### Part 2: Identifying Substances by Density (Sample A, B, C) #### Sample A: 225 grams, 50 milliliters
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check for understanding use your understanding of density to complete t…
B. vegetable oil, 0.71 g/mL ### Part 2: Identifying the metal samples #### 1. Sample A: 225 grams, 50 milliliters
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chapter 20: chemistry 11.8.1 high resistance to... the area is called a…
Assuming the options are related to chemistry lab liquid expulsion under pressure, and if we correct the OCR - garbled options, the correct answer would be the option related to f…
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exercise b suppose you are writing a report about cancer research and c…
The article is credible. It cites a credentialed researcher (Dr. Folkman), reports experimental results, and includes cautionary notes about human application, showing balanced an…
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3. fill in the following chart. don’t forget to come the isotope symbol…
To solve this, we use the following relationships: - Atomic number (\(Z\)) = number of protons (\(p^+\)) - Mass number (\(A\)) = number of protons (\(p^+\)) + number of neutrons (…
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lesson 37 continued 2. a brochure about home security systems, publishe…
The article has reasonable credibility. Dr. Folkman’s credentials (research scientist at a medical research center) give expertise. The major newspaper has basic fact - checking s…
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3. use the graph paper on the back of this page to plot the data in the…
Approximately 0.94 g/mL (or more precise 0.938 - 0.94 g/mL) ### Part b:
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look at the picture. then, choose the best answers. 2. choose the best …
intensive ### Question 3
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periodic table assignment magnesium is in group □ and period □. gallium…
Magnesium: group 2, period 3; Gallium: group 13, period 4
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19. choose the best answer. who reasoned that it is impossible for all …
B. Democritus
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who proposed the law of definite proportions? ○ crookes ○ thomson ○ pro…
C. Proust ### Second Question (Who discovered the nucleus?):
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16. choose the best answer. how many valence electrons does iodine have…
7 (corresponding to the option with 7)
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15. choose the best answer. who proposed that matter could only be divi…
A. Democritus
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jill mixes two types of concentrations of hcl (hydrochloric acid): 0.37…
50% (Option: 50%)
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physical science study guide – chapter 4 name: be sure to study these q…
a) Kinetic ### Question 2
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ws: ideal gas and more answer the following showing your work and prope…
7.69 L
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3. true or false: analytical chemistry focuses on identifying the compo…
True
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atomic model proposed by j. j. thomson model shows negative electrons f…
The atomic model proposed by J.J. Thomson is the one with the description "model shows negative electrons floating in a'soup' of positively charged material" (corresponding to the…
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2. which branch studies energy and reaction rates? a) biochemistry b) p…
b) Physical Chemistry
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13. match the statements with the pictures. answers can be used more th…
### Matching the Atomic Models: #### 1. Atomic model proposed by Dalton (A) - Dalton's model (A) is a solid sphere, representing the idea that atoms are indivisible and indestruct…
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1. match the branch of chemistry with the correct example: branch examp…
Organic Chemistry: B. Plastics and fuels Inorganic Chemistry: C. Iron and table salt Biochemistry: A. DNA and proteins
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the number of protons in an atom determines an atom’s identity and affe…
Top (lowest protons): neon Next: magnesium Next: silver Bottom (highest protons): plutonium (Order: neon, magnesium, silver, plutonium)
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how many electrons are found in each energy level of a neutral atom of …
- third energy level: three electrons - first energy level: two electrons - second energy level: eight electrons
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an atom of iron has an atomic number of 26 and a mass number of 56. how…
26 protons, 30 neutrons, 26 electrons (corresponding to the third option among the given choices) ### Second Question (Atomic Number and Neutrons Statement)
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14. an agency of the usa department of labor whose function is to regul…
Occupational Safety and Health Administration (OSHA) ### Question 15
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periodic table of the elements get help here an atom that has four prot…
An atom that has three protons.
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identify some of the important similarities and differences between the…
To solve this, we analyze each description and match it with protons, neutrons, or electrons: ### 1. Determines the atomic number The atomic number is equal to the number of proto…
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question 4 of 30 the graph below shows how the pressure and volume of a…
D. The pressure decreases.
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26 the letters ph denote _________________, which is the relative degre…
potential of hydrogen (or power of hydrogen); acidity; alkalinity ### Question 27
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which of the following is a heterogeneous mixture? a. gold alloy b. rub…
D. Paint
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6. susceptible host | an individual who is at an \increased risk\ for i…
To solve these fill - in - the - blank questions related to medical and health concepts, we analyze each one: ### Question 8 - **Explanation**: When a pathogen is transmitted from…
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question 1 of 30 what is the volume of 0.24 mol oxygen (o₂) gas at 345 …
D. 9.1 L