化学
化学反应、化学计量、分子结构与元素性质。
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a ______ is the force that holds atoms together in a compound. synthesi…
chemical bond
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2/53 when nitrogen becomes an ion, what is its oxidation number? -3 +5 …
-3
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1/53 predict the bond that will form between s and o. ionic covalent
Covalent
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question 4. a chemist is designing a new compound and wants to predict …
A. Carbon (C) C. Nitrogen (N) E. Sulfur (S)
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question 3. which of the following statements explains why potassium (k…
B. Potassium's outermost electron is farther from the nucleus, making it easier to lose.
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question 2. complete the following statements about periodic trends in …
I. increases II. less reactive III. less reactive; more reactive
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in the chemical equation, fe(s) + o₂(g) → fe₂o₃(s), what is the state o…
C. Gas ### Second Question (Type of Reaction)
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which reaction type is the following? * zn + 2hcl → zncl₂ + h₂ ○ single…
A. Single Replacement ### Second Question:
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at a certain p and t, a gas occupies 20 l. if p and t are held constant…
B. 10 L
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balance the following equation: ___ $p_4$ + ___ $o_2$ → ___ $p_2o_5$ * …
\( \boldsymbol{P_4 + 5O_2 ightarrow2P_2O_5} \) (the first option) ### Second Sub - Question (Identifying Single - Replacement Reaction)
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which of the following is a combustion reaction? \\( \\mathrm{c}_3\\mat…
First Question: A. \(C_3H_8 + 5O_2 ightarrow 3CO_2 + 4H_2O\) Second Question: C. \(3CuCl_2 + 2Al ightarrow 2AlCl_3 + 3Cu\)
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which chemical equation represents a double replacement reaction? 2na +…
\(\text{NaOH} + \text{HCl} ightarrow \text{NaCl} + \text{H}_2\text{O}\) (the fourth option)
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which of the following is a decomposition reaction? * \\( \\mathrm{al}_…
First Question: \( 2\text{HgO} ightarrow 2\text{Hg} + \text{O}_2 \) (the second option in the first question) Second Question: \( 2\text{C}_2\text{H}_6 + 7\text{O}_2 ightarrow 4\t…
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which of the following is a synthesis reaction? * fe + cucl₂ → fecl₂ + …
\( \boldsymbol{\text{SO}_2 + \text{H}_2\text{O} ightarrow \text{H}_2\text{SO}_3} \) (the option with this reaction) ### Second Question (Double Replacement Reaction)
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which represents a balanced chemical equation? * \\( \\mathrm{co_2 + h_…
$\ce{CH_{4} + 2O_{2} -> CO_{2} + 2H_{2}O}$ (the third option: $\boldsymbol{\ce{CH_{4} + 2O_{2} -> CO_{2} + 2H_{2}O}}$)
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which equation represents a synthesis chemical reaction? * 2 points 2s …
A. \(2\text{S} + 3\text{O}_2 ightarrow 2\text{SO}_3\)
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which represents a balanced chemical equation? * 2 point ○ co₂ + h₂o → …
C. \( \ce{CH4 + 2O2 -> CO2 + 2H2O} \) ### Second Question (Law for Balanced Reactions)
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this equation represents a balanced chemical reaction: fe(s) + cuso₄(aq…
C. Single Replacement ### Second Question (Reactants in \( \text{HgO} ightarrow \text{Hg} + \text{O}_2 \))
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what type of reaction involves multiple reactants forming one product? …
B. Synthesis ### Second Question:
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this equation represents an unbalanced chemical reaction: al + o₂ → al₂…
2 (the option with "2") ### Second Sub - Question (Identifying Reaction Type)
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this unbalanced equation represents a chemical reaction: cu(no₃)₂ + nai…
1
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how do greenhouse gases trap heat? they chemically combine to create su…
The correct option is: They reflect solar radiation back towards the Earth.
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question 24 a mixture of 10.0 g of ne and 10.0 g of ar have a total pre…
1.10 atm (the option with "1.10 atm")
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consider the following (incomplete) reaction. how many l of carbon diox…
2.88 L
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a sample of f₂ gas occupies 1.120 l when held at 273.15 k. what was the…
812 mL (corresponding to the option "812 mL")
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what volume (in ml) will a sample of f₂ gas occupy in a syringe at 5.5 …
5.5 mL (corresponding to the option "5.5 mL")
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a gas - filled weather balloon with a volume of 52.0 l is held at groun…
641 L (corresponding to the first option: 641 L)
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how do gas particles respond to an increase in volume? - increase in te…
The correct option is the third one (the option with "decrease in temperature and decrease in pressure"). Wait, no—wait the options are: 1. increase in temperature and decrease in…
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a football that is inflated to maximum capacity while held inside a war…
The option: "volume and temperature are directly related; when one decreases, so does the other"
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consider the graph shown below, then select all of the statements that …
II,IV
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the (balanced) reaction for the combustion of ethanol (c₂h₅oh) is shown…
21.4 g (corresponding to the option "21.4 g")
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given the tabulated bond enthalpies, estimate the enthalpy of reaction …
-808 kJ
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which bond would you expect to have the lowest bond energy? o h-f o h-b…
H-I (the option with the blue dot, labeled H-I)
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which bond would you expect to have the lowest bond energy? o h-f o h-b…
O H-I
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given the following tabulated data, calculate the enthalpy of reaction …
-2220 kJ (Option: -2220 kJ)
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which of the following represents a formation equation for c₆h₅oh(l)? ○…
The fourth option (6 C(s) + 3 H₂(g) + 1/2 O₂(g) → C₆H₅OH(l))
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given the following thermochemical equations, determine the enthalpy of…
-1075 kJ (corresponding to the option -1075 kJ)
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140.0 g of metal at 24.0°c has 632 j of heat added to it. the metal’s s…
67.0°C (Option: 67.0°C)
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a system that does work to push back a piston but transfers no heat to …
The correct option is: \(w < 0, q = 0, \Delta E < 0\) (the first option in the list, assuming the first option is labeled with this description).
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which process is shown in the following enthalpy diagram: enthalpy diag…
A. exothermic; $\ce{H2O(g) -> H2O(l) + 40.7\ \text{kJ}}$ (assuming the first option is this, as per the description)
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which process is shown in the following enthalpy diagram: h, enthalpy h…
exothermic: $\ce{H2O(g) -> H2O(l) + 40.7\ \text{kJ}}$ (the first option in the list, likely labeled as the first radio button option with that text)
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instant cold packs used to treat minor bruises and cuts are commonly ma…
A. It is an endothermic reaction, absorbing heat from its surroundings, therefore feeling "cold".
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scientists are concerned about melting glaciers and ice sheets. why are…
The correct option is "This causes a decrease in albedo and warms the earth." (the second option among the given choices).
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consider a system of gases that is compressed using 986 j from a piston…
+624 J (the option with +624 J)
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write the empirical formula for at least four ionic compounds that coul…
\(Fe(NO_{3})_{2}\), \(Fe(CN)_{2}\), \(Pb(NO_{3})_{4}\), \(Pb(CN)_{4}\)
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order the steps to take when drawing electron dot diagrams. count the d…
1. Use the periodic table to find the chemical symbol of the atom and the number of electrons in the valence shell. 2. Write the chemical symbol of the atom. 3. Draw dots around t…
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classify each bond as covalent, ionic, or metallic according to its des…
# Explanation: ## Step 1: Analizar el enlace en un anillo de oro puro Los enlaces metálicos ocurren en metales puros (como el oro). Los átomos metálicos comparten un "mar de elect…
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name: _______________ pd: ______ chemistry u3l14_q2 ct module day 3 iiw…
(a) Element: Potassium (K); Electron configuration: $1s^22s^22p^63s^23p^64s^1$ (b) The 1s peak of Ca appears to the left of K's 1s peak because Ca has a higher nuclear charge, inc…
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johanna is studying what happens to the energy as a ball rolls down a r…
gravitational potential energy
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a mixture of n₂, o₂ and he have mole fractions of 0.25, 0.65, and 0.10,…
0.975 atm
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a mixture of 4.0 g h₂(g) and 10.0 g he(g) in a 4.3 l flask is maintaine…
5.12 atm
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part 2 of 2 how many moles of cl is this? answer in units of mol. 1. 1.…
2. 1.09323
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part 1 of 2 zinc chloride (zncl₂) is 52.02% chlorine by mass. what mass…
9. 32.3044
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how many moles are in 4.30 g of h₂o? answer in units of mol. 1. 0.12208…
4. 0.238624
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select the correct answer. how does regular exercise help make us more …
C. During exercise the brain releases endorphins, the chemicals that help improve our mood.
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what is the mass of 4.100 mol ca(oh)₂? answer in units of g. 1. 333.45 …
7. 303.81
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a 10.5 l sample of gas at 292 k contains o₂ at 0.622 atm and n₂ at 0.51…
0.273 mol
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b. a chemist raised the temperature of a liquid 45°f in 1 minute. what …
\(0.75^{\circ}F\) per second.
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a 10.5 l sample of gas at 292 k contains o₂ at 0.622 atm and n₂ at 0.51…
1.139 atm
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what is the total pressure of the sample of gas mixture? 1.139 atm 2.00…
(Assuming the context of Dalton's Law of Partial Pressures where we sum partial pressures, and if partial pressures lead to 3.02 atm as the total) 3.02 atm
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during a titration of hcl$_{(aq)}$ with naoh$_{(aq)}$, the naoh$_{(aq)}…
i | a base, ii | an acid
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a sample solution of hno₃(aq) and the indicator bromothymol blue were t…
II and IV
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question 4 0.5 pts the major abiotic reservoir for phosphorus is ______…
rock
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question 1 0.5 pts the atmosphere is approximately 80% ______ gas. ○ ch…
N₂
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directions: write t for true or f for false. if false, correct the stat…
F; Correct statement: When two liquids are mixed, no matter disappears (matter is conserved). ### Question 7
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39 of 80 concepts completed fill in the blank question the beta-lactam …
penicillin (or beta - lactam antibiotic, with penicillin being a specific example)
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write the empirical formula for at least four ionic compounds that coul…
\(Fe(NO_{3})_{2}\), \(Fe_{3}(PO_{4})_{2}\), \(Fe(NO_{3})_{3}\), \(FePO_{4}\)
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try again your answer for at least one of your compounds is incorrect. …
\(NH_4CH_3CO_2\), \(NH_4NO_3\), \(Fe(CH_3CO_2)_3\), \(Fe(NO_3)_3\)
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multiple choice question the active part of the penicillin structure is…
A. beta - lactam
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__________ is not only the most valuable precious metal, but it is also…
d. Gold
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question 10 which of the following is not typical of most hydrocarbons?…
D. high melting point
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the electron dot diagram shows the arrangement of dots without identify…
B. tellurium (Te)
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what type of compound is $\\ce{ch_{2}=ch-ch_{2}-ch_{3}}$? a branched al…
D. alkene
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hydrocarbons are the primary constituents of ______. a fruit juices b d…
C. fuels
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what information on the periodic table is used to complete electron dot…
The number before the A at the top of a column shows how many dots to draw in the diagram.
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the carbon atoms in saturated hydrocarbons ______. a have only single b…
A. have only single bonds
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which of the following is true of iron? a. it has the highest electrica…
D. It is a durable metal and is commonly used for casting.
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which of the following is not true of silver? a. it has the highest ele…
C. It is a copper alloy, usually mixed tin as the main additive.
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a precious metal is a. an element with super and electric and thermal c…
B. a highly sought after dense, shiny, soft precious metal that has been used as money for many centuries.
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what is the iupac name of the following compound? (chemical structure i…
2 - methylpropane
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what is the iupac name of an isomer for the following compound? ch₃-ch₂…
B. 2 - methylbutane
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7. homemade ice cream mix an ice-salt bath is made using 0.500 kg of wa…
-20.1°C
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which of these formulas is the condensed structural formula for an alka…
B. \(CH_3 - CH_2 - CH_3\)
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with your class what have we figured out so far about gasoline, diesel,…
The subfield in Natural Science that best applies is Environmental Sciences (or Engineering, Chemistry depending on the focus, but Environmental Sciences is more about the impact …
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__________ is a durable material and is widely used for casting, which …
A. Bronze
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what is the iupac name of this compound? ch₃-ch₂-ch₂-ch₂-ch₂-ch₂-ch₃ a …
B. heptane
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question 1 an organic compound composed of carbon and hydrogen connecte…
C. alkane
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hee sun drew an electron dot diagram of a silicon atom as shown. in add…
B. The same number of dots would appear in the diagram for carbon.
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ch₄ dot structure: complete octet: lewis dot structue:
- Dot Structure (Lewis Dot Structure): $$\begin{array}{c} \ce{H}\\ |\ \\ \ce{H - C - H}\\ |\ \\ \ce{H} \end{array}$$ - Complete Octet: Carbon has 8 electrons (4 bonds, each bond i…
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which is a force that holds atoms together? chemical bond electron shel…
A. chemical bond
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based on the location of nitrogen (n) on the periodic table, how many a…
B. three
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lead is malleable, so it can be pounded into flat sheets without breaki…
Metallic bonds involve many valence electrons shared by many atoms, so the bonds can move around as the metal is pounded.
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the electron dot diagram shows the arrangement of dots without identify…
D. arsenic (As)
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6. salt for de-icing roads road crews spread rock salt on icy pavement,…
$-1.6\ ^\circ\text{C}$ (rounded to two significant figures)
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fluorine (f) and bromine (br) are in the same group on the periodic tab…
Both a fluorine atom and a bromine atom gain one electron, and both atoms become stable.
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when sodium atoms (na) and chlorine atoms (cl) join to make sodium chlo…
A. potassium (K) and fluorine (F)
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helium (he) and neon (ne) are elements in group 8a of the periodic tabl…
A. The electron dot diagram of helium has six fewer dots than the electron dot diagram of neon. A. The electron dot diagram of helium has six fewer dots than the electron dot diag…
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describing electron dot diagrams complete the passage to describe how e…
First blank: eight; Second blank: two
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bohr model of cl₂ lewis dot structures of cl₂ in a lewis dot structure,…
A. A chlorine molecule has 14 total valence electrons. C. There are two bonding electrons in a chlorine molecule. D. There are three lone pairs in a chlorine molecule. (Nota: La o…
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which model correctly represents the electron dot diagram of antimony? …
The third option (·Sb· with 5 dots)