化学
化学反应、化学计量、分子结构与元素性质。
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unit 6 lesson 6 additional practice problems 1. the two graphs show mod…
The weed represented by the graph with the lower y - intercept (smaller initial value on the y - axis at \( d = 0 \)) covered a smaller area when the chemicals were applied. We kn…
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select the correct answer. which of the following is a major disruptor …
D. burning of fossil fuels
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3. try another one. consider a fictitious molecule, x₅ya₃. the molar ma…
\(139.25\)
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name______ first semester review worksheet-version 2 to receive any cre…
\(3.76\times10^{23}\) molecules ### Question 2:
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which of the following supports the main idea of the text? a to buy cig…
C. The tobacco leaves they harvest have dangerous chemicals on them: nicotine and pesticides.
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a chemist mixes 4 liters of one acid solution with 10 liters of a 40% s…
0.05
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7. what does the term \tolerance\ refer to in the context of addiction?…
7. B. Needing more of the drug to feel the same effects 8. D. Drinking large quantities of alcohol in a short period 9. C. Lay them on their side (BACCHUS) 10. B. To track alcohol…
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nov 1, 2025 homework due 11.5.25 rock transformation chapter 3/lesson 4…
1) Land is made out of rocks and soil. 2) Rocks are made out of one or more minerals. 3) The rock cycle describes three things: how rocks are formed, how they break apart, and how…
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goal: create a model that represents groups of atoms that could make up…
A valid repeating group for Sample 2 is: ``` H H | | H-C-C-H | | H H ``` (This is ethane, $C_2H_6$, which is a colorless liquid/gas near room temp, matches the gasoline-like hydro…
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1. a student conducted an experiment with a chamber filled with nitroge…
1. B. She placed the chamber in an ice bath. 2. | Oxygen Molecules Before Cooling | Oxygen Molecules After Cooling | |----------------------------------|--------------------------…
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5. explain why understanding bonding is important for understanding mol…
Understanding bonding is critical because it defines the structure, stability, and properties of molecules. Bonding determines how atoms arrange themselves to form molecules, whic…
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. what is the empirical formula for a compound that is 50.8% zinc, 16.0…
s: 4. (Original work had errors, but intended answer) $\boldsymbol{ZnPO_2}$ (Note: Correct empirical formula should be rechecked, but based on original work, ZnPO₂) 5. (Simplified…
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directions: show all of your work for each of the following problems. u…
$\boldsymbol{C_3H_7}$ ### Problem 2:
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6 pour chacune des réactions globales suivantes, déterminez : 1) les éq…
Pour résoudre la variation d'enthalpie molaire standard de la réaction globale, on utilise la **loi de Hess** (ou la relation entre l'enthalpie de réaction et les enthalpies de fo…
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question 4 (1 point) which one of these are not an example of how schem…
Question 4: Telling someone your darkest fears within the first five seconds of sitting next to them at the local burger shop. Question 5: Assumption
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exercices 7 chaque transformation énoncée ci-dessous représente-t-elle …
A) P B) C C) P D) P E) C F) P G) C H) C I) P
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5. pour chaque changement mentionné, indiquer le ou les indices qui per…
A) C. Une grande quantité d'énergie est dégagée. B) A. Il y a un changement de couleur, F. Le changement n'est pas réversible C) B. Il y a un changement de température, D. Il se d…
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4. parmi les transformations suivantes, cochez celles qui représentent …
B) Les feuilles des arbres qui rougissent à l'automonne. C) Une tranche de pain qui est digérée. F) Un jeans qui se décolore sous l'action de l'eau de Javel. H) Le moteur de la to…
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what is the % yield if 20 grams of hydrogen is reacted with 32 grams of…
25 %
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what is the % yield if 4 moles of hydrogen is reacted with 3 moles of o…
75%
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an organic synthesis to make the pain reliever acetominophen is suppose…
80%
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if we react 30 grams of ethane ($c_2h_6$) with 320 grams of oxygen, how…
88 grams
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consider the combustion of ethane reaction below for the next two quest…
8
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which are transformations that occur in an incandescent light bulb? sel…
a. electrical to thermal energy, b. electrical to radiant energy
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how many grams of water are produced if we react 3 moles of hydrogen wi…
About 60 grams
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consider the combustion of hydrogen for the next two questions. $2h_2(g…
Hydrogen and 10 moles water produced.
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presidential retreat adapted from the national parks service catoctin m…
It is a place where Presidents can relax, unwind, contemplate, entertain distinguished guests in an informal setting, and cope with the pressures of modern-day society. Many histo…
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excerpt from a journey to the center of the earth by jules verne lookin…
B. The narrator appeases his uncle’s whims.
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select the correct text in the passage. which detail best shapes the id…
A friend is a person with whom I may be sincere.
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question # 4 multiple choice which term best describes the type of farm…
D. organic
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which of the following is the atomic radius of chlorine if the internuc…
a. 100 pm
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atoms tend to be most stable when their outermost energy level contains…
a. a full set of valence electrons
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2/10 energy levels are fixed distances from the of an atom where electr…
nucleus
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electrons in the outermost energy level are called ______ electrons. en…
valence
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5 select the correct texts in the passage. which two phrases in the exc…
To solve this, we analyze context clues for "careening": ### Step 1: Analyze "bumping into my tea before careening off into a corner" The phrase "bumping into my tea" suggests a f…
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3. write down the volume of water in each set of beakers. set a 730 ml …
Set B has the greatest volume of water. The volumes are Set A: 730 ml, Set B: 1250 ml, Set C: 1100 ml. Since 1250 > 1100 > 730, Set B is the answer.
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question 10 of 10 a nonrenewable resource consisting of hydrocarbons fr…
D. fossil fuel
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question 5 of 10 the chemical reaction that occurs when gasoline and ai…
C. combustion reaction
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question 10 of 10 what atom should be balanced last when balancing hydr…
C. The oxygen atoms
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question 9 of 10 what reactants form a combustion reaction? a. water va…
B. A hydrocarbon and oxygen
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question 8 of 10 what is a combustion reaction? a. a reaction between a…
A. A reaction between a molecule and oxygen that produces heat
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question 5 of 10 which of the following is the correct model of $\\ce{c…
A. The model with the chain that represents 8 carbon atoms (the zig - zag chain long enough for \( C_8H_{18} \))
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question 4 of 10 what coefficient would the o₂ have after balancing c₃h…
A. 5
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question 3 of 10 which of the following is a combustion reaction? a. na…
C. $\ce{C_{3}H_{8} + 5O_{2} -> 3CO_{2} + 4H_{2}O}$
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question 2 of 10 what are all the products of a hydrocarbon combustion …
B. Carbon dioxide, water vapor, and heat
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question 1 of 10 what special information does the ball-and-stick model…
D. The ball - and - stick model shows the shape of the molecule.
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question 10 of 10 how many zn atoms are in zn(clo₃)₂? a. 1 b. 6 c. 3 d.…
A. 1
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question 9 of 10 what coefficient is needed to balance the reaction cac…
D. \( 2\text{HCl} \)
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question 8 of 10 what has a complete ionic equation of mg(s) + zn²⁺ + 2…
C. \( \text{Mg}(s) + \text{Zn(NO}_3\text{)}_2(aq) ightarrow \text{Mg(NO}_3\text{)}_2(aq) + \text{Zn}(s) \)
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question 6 of 10 if a reaction starts with 6 atoms of a solid and 12 at…
A. They will contain 18 atoms total in all the products.
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question 5 of 10 what does a complete ionic equation look like? a. all …
A. All ionic substances are written as separate ions in solution.
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question 4 of 10 what are the spectator ions in $\\ce{mg(s) + zn^{2+} +…
D. \( \text{NO}_3^- \)
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question 3 of 10 which of the following best describes a balanced react…
D. A reaction that has the same number and type of atoms on each side of the equation
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question 1 of 10 how is a net ionic equation written from a complete io…
B. The spectator ions are removed.
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question 10 of 10 what does it mean if a substance is soluble? a. it di…
A. It dissolves in water.
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question 9 of 10 what happens in a synthesis reaction? a. one substance…
C. Two substances combine to form a single new substance.
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question 8 of 10 what reaction shows a compound breaking apart into sep…
A. A decomposition reaction
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question 7 of 10 what kind of reaction is represented by fe + cuso₄ → c…
A. A single - replacement reaction
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question 6 of 10 what is the activity series of metals? a. a list of me…
D. A list of metals arranged in order of reactivity
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question 5 of 10 which of the following best describes a double - repla…
A. Atoms in one compound switch places with atoms in another compound.
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question 4 of 10 which of the following demonstrates a double - replace…
A. \(Na_{3}PO_{4}+MnCl_{2} ightarrow Mn_{3}(PO_{4})_{2}+NaCl\)
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question 3 of 10 which of the following is an example of a synthesis re…
A. \( \ce{H_2 + Br_2 ightarrow 2HBr} \)
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question 2 of 10 what happens in a single - replacement reaction? a. tw…
D. One reactant replaces an element in another reactant.
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question 1 of 10 which of the following is an example of a decompositio…
C. \( 2\text{NaCl} ightarrow 2\text{Na} + \text{Cl}_2 \)
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question 10 of 10 what are state symbols in a chemical equation? a. sym…
B. Symbols telling what form of matter the substances are in
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question 9 of 10 identify the reactants in the reaction hcl + naoh → na…
D. HCl and NaOH
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question 8 of 10 which of the following is the best definition of a che…
D. A change in a substance where one or more new substances form
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question 7 of 10 if the reactants of a reaction have one s and four o a…
A. One S atom and four O atoms
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question 6 of 10 which of the following is the most likely sign that a …
B. Two liquids are mixed at room temperature and a gas forms.
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question 5 of 10 which of the following describes a chemical reaction? …
D. Atoms in substances react with each other.
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question 4 of 10 what are the substances you start with in a chemical r…
C. The reactants
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question 3 of 10 where are the products in a chemical equation located?…
C. On the right side of the arrow in the equation
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question 2 of 10 which of the following reactions shows a physical chan…
D. $\text{NaCl}(s) ightarrow \text{NaCl}(aq)$
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question 1 of 10 which of the following represents a physical change? a…
A. Phase changing
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question 10 of 10 how does one determine a molecular formula from the e…
A. Multiply subscripts in the empirical formula by \(\frac{\text{molar mass}}{\text{empirical formula mass}}\)
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question 9 of 10 what is the percent composition of sulfur in so₂? a. \…
B. \(\frac{32.1\ \text{g}}{(32.1\ \text{g} + 16.0\ \text{g} + 16.0\ \text{g})} \times 100\%\)
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question 8 of 10 what is the molecular formula of the compound ch₂ with…
C. \( C_3H_6 \)
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question 7 of 10 what does percent composition tell you about a molecul…
D. It tells you how much of a molecule is made up of each element.
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question 6 of 10 so₃ is an empirical formula for which of the following…
A. \(S_2O_6\)
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question 5 of 10 which of the following represents the mass of 1 molecu…
C. 34.1 amu
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question 4 of 10 which conversion factor would be used to convert g/mol…
C. mol/L
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question 3 of 10 what is the molar mass of a compound? a. the mass in g…
A. The mass in grams of 1 mole of the compound
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question 2 of 10 how does one determine an empirical formula from a per…
D. Convert mass percents to moles and then divide by the smallest mole value to get subscripts
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question 1 of 10 how many atoms are in 64 g sulfur (s)? a. 32(6.02×10²³…
C. \(2(6.02\times 10^{23})\) atoms
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question 9 of 10 what is the molarity of 6 moles (mol) of nacl dissolve…
B. $\frac{6\ \text{mol}}{2\ \text{L}}$
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question 7 of 10 what is made when a salt is dissolved in water? a. a s…
A. A solution
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question 6 of 10 what is molarity? a. a measurement of the concentratio…
A. A measurement of the concentration of a solution
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question 5 of 10 which of the following best describes a mole as used i…
B. A very large number of objects
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question 1 of 10 how many atoms does 32 g of sulfur contain? a. $32 \\t…
B. \( 6.02 \times 10^{23} \)
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look at this sentence: the hunters identified traces of the deer in the…
1. tracks or other signs left behind by the passing of a person or animal: The search party found no trace of the missing hikers.
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2) \\underline{6} k + \\underline{\\quad} b₂o₃ → \\underline{3} k₂o + \…
6, 1, 3, 2 ### Problem 3:
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7 multiple choice 5 points select the correct formula for potassium iod…
7. KI 8. $\text{CuCl}_2$
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5 multiple choice 5 points select the correct formula for carbon disulf…
5. $\text{CS}_2$ 6. $\text{Fe(SO}_3\text{)}_2$
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2 multiple answer 5 points select the four signs of chemical reactions …
## Question 2: - Unexpected color change - Formation of a precipitate - Formation of a gas - Formation of heat and/or light ## Question 3: Production of a gas
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4. francis galton was influential in founding which of the following fi…
D. eugenics
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which of the following best describes peat? a liquid form of fossil fue…
an early stage of coal formation
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what is the main component of coal? helium carbon hydrogen oxygen
carbon
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at what temperature does water turn from liquid to steam? 0°f 212°f 50°f
212°F
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what was the primary focus of rachel carson’s book \silent spring\? che…
chemical use in society
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how does chemical weathering occur? plants, lichens, and mosses acceler…
by chemically breaking down rocks by water and gases