化学
化学反应、化学计量、分子结构与元素性质。
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estimate the enthalpy of reaction (in kj) for the following reaction, g…
\(-164\)
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using the given information, calculate the standard enthalpy of reactio…
-129.7
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question 1 1 pts valence bond theory teaches that a __________results w…
covalent bond
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which of the following best represents a formation equation? c(graphite…
\( \boldsymbol{\text{C}(\text{graphite}) + \frac{3}{2}\text{H}_2(\text{g}) + \frac{1}{2}\text{Cl}_2(\text{g}) ightarrow \text{CH}_3\text{Cl}(\text{g})} \) (the first option in the…
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formative # 7 - energy changes and rates of reactions -... question 5 (…
3
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question 4 (1 point) saved for the reaction, xa + yb --> products, the …
increasing the concentration of B will have no effect on the rate
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question 6 (1 point) use the following information to answer the next q…
3402 J (corresponding to the option: 3402 J)
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effective nuclear charge and atomic radius 41. which electrons experien…
The valence electrons in nitrogen experience a greater effective nuclear charge. This is because nitrogen (atomic number 7) has a greater atomic number than beryllium (atomic numb…
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formative # 7 - energy changes and rates of reactions -... false questi…
3
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question 2 (1 point) saved according to the collision theory, the crite…
True
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47. determine the number of valence electrons in each element: a. ba b.…
To determine the number of valence electrons for each element, we use their positions in the periodic table (group number for main - group elements, and electron configuration ana…
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convert 281.1 kpa to torr. report your answer to the nearest whole numb…
\(2108\) (if we use the more accurate \(\frac{760}{101.325}\) conversion factor: \(\frac{281.1\times760}{101.325}=\frac{213636}{101.325}=2108.424\approx2108\) when rounded to the …
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question 4 (1 point) when 6.000 moles of glucose are combusted, 16 815 …
$\ce{C6H12O6(s) + 6O2(g) -> 6CO2(g) + 6H2O(\ell)}$ with $\Delta H = -2802.15\ \text{kJ}$ (the fourth option: $\boldsymbol{\ce{C6H12O6(s) + 6O2(g) -> 6CO2(g) + 6H2O(\ell)}}$ $\bold…
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what else is produced during the combustion of butane, c₄h₁₀? 2c₄h₁₀ + …
C. \(CO_{2}\)
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what does the octet rule state that explains why atoms bond? an atom bo…
A. An atom bonds to have eight valence electrons to become stable.
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(b) dry hydrogen gas was reacted with iron fillings using the set up be…
(i) $$Fe + 2HCl \xrightarrow{\Delta} FeCl_{2}+H_{2}$$ (ii) $$2H_{2}+O_{2}\xrightarrow{\text{Flame}}2H_{2}O$$
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consider the following thermochemical equations. no(g) + o₃(g) → no₂(g)…
The enthalpy change for the reaction $\ce{2 NO_{2}(g) -> 2 NO(g) + O_{2}(g)}$ is $\boxed{+113.2\ \text{kJ/mol}}$ (or check the calculation again for possible sign errors, but base…
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question 3 (1 point) the enthalpy of formation of an element in its mos…
zero (the option corresponding to "zero")
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question 2 (1 point) a solid sample of granite, mass 200 g, is cooled s…
28.7 °C (Option: 28.7 °C)
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question 1 (1 point) use the following information to answer the next q…
478 kJ (corresponding to the option "478 kJ")
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convert 460.5 kpa to torr. report your answer to the nearest whole numb…
\(3454\)
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use the bond enthalpies given below to estimate the enthalpy of reactio…
\(-557.3\) kJ/mol
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question 5 use the bond enthalpies given below to estimate the enthalpy…
\(-19.5\space kJ/mol\)
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consider the following thermochemical equations. no(g) + o₃(g) → no₂(g)…
$-190.9\space kJ/mol$
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consider the following thermochemical information. 2 al(s) + 3/2 o₂(g) …
\(-780\mathrm{kJ/mol}\)
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select all of the following substances that you expect to have a non - …
- $\text{CH}_4(g)$ - $O(g)$
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figure 2: the bef₂ molecule adopts a linear structure in which the two …
The bond angle in \( \text{BeF}_2 \) is larger than the bond angle in \( \text{H}_2\text{S} \). ### Question 2
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25.0 ml of an lioh solution was titrated with 29.15 ml of a 0.205 m h3p…
\(0.717\ M\)
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29.4 ml of a ch3cooh solution was titrated with 18.5 ml of a 0.175 m li…
\(0.110\space M\)
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18.35 ml of an hcn solution was titrated with 35.4 ml of a 0.268 m naoh…
\(0.517\space M\)
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what is the endpoint in relation to a titration? the point where the co…
The point where the color changes for the indicator during the titration.
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what does the word titrant refer to for a titration? the chemical for w…
The chemical for which both the concentration and volume are known.
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related to titration, what is an analyte? the chemical for which the vo…
The chemical for which the volume is known, but the concentration is not.
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what does equivalence point refer to during a titration? the chemical f…
The point where moles of acid equals moles of base.
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4. calculate the volume of a liquid with a density of 5.45 g/ml and a m…
Approximately $11.93\ \text{mL}$ (or more precisely $\frac{65}{5.45} \approx 11.93$ mL)
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both vanadium and its 3+ ion are paramagnetic. use electron configurati…
- Electron configuration of V (atomic number 23): $\boldsymbol{[Ar] 4s^2 3d^3}$ (has 3 unpaired $3d$ electrons). - Electron configuration of $\boldsymbol{V^{3+}}$: Loses 3 electro…
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what is the balanced equation for this reaction? hclo₄ + mg(oh)₂ →
\(2HClO_4+Mg(OH)_2 = Mg(ClO_4)_2 + 2H_2O\)
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what is the balanced equation for this reaction? hno₂ + nh₄oh → 2hno₂ +…
\(HNO_2+NH_4OH = NH_4NO_2 + H_2O\)
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what is the balanced equation for this reaction? hf + ca(oh)₂ → 2hf + c…
\(2HF + Ca(OH)_2 = 2H_2O+CaF_2\) (the first option \(2HF + Ca(OH)_2\to2H_2O + CaF_2\))
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review exercises multiple choice choose the correct answer. 1. the righ…
1. C. tricuspid valve 2. B. pericardium 3. A. septum 4. D. infarct 5. C. transfusion 6. B. shunt 7. C. heart 8. D. cardiomyopathy 9. D. cardiomegaly 10. D. perfusion 11. B. pulmon…
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which scientist developed the first model of the atom that proposed the…
Thomson
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109. write orbital diagrams for each ion and determine if the ion is di…
To solve this, we analyze each ion by determining its electron configuration, then constructing the orbital diagram and checking for unpaired electrons (paramagnetic has unpaired,…
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the simple model below is a neutral magnesium (mg) atom with the elemen…
It must lose two electrons and become an ion.
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which is the electronic configuration for oxygen? 1s² 2s² 2p¹ 1s² 2s² 2…
\(1s^{2}2s^{2}2p^{4}\) (the third option)
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while looking at xenon (xe) on the periodic table, a student needs to f…
A. directly up
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which of the following symbols would be included in the noble gas notat…
Kr
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103. write condensed electron configurations and orbital diagrams for e…
To solve this, we'll find the condensed electron configurations and orbital diagrams for each species. The condensed electron configuration uses the noble gas core (the electron c…
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which statement best describes how electrons fill orbitals in the perio…
Electrons fill orbitals in order of their increasing energy from left to right.
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which statement describes a property of a proton? ○ is found outside th…
has a positive charge
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atom a and atom b have the same number of protons, but they do not have…
Atom A and Atom B are isotopes of the same element.
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when an atom that has no charge loses two electrons, it becomes a posit…
positive ion.
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this is how sodium appears in the periodic table. the arrow is pointing…
atomic mass
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someone considering a career as a resource scientist most likely enjoys…
chemistry and physics
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question 11 viscosity is the characteristic of a fluid that resists • s…
- **Question 11**: flow - **Question 12**: heat
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dinitrogen monoxide - no₂ sulfur trioxide - so₃ phosphorus pentachlorid…
B. $\text{NO}_3^-$, C. $\text{SO}_4^{2-}$
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the bond formed by the complete transfer of electrons from an electropo…
ionic bond.
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select all substances most likely covalent, formed from nonmetal atoms …
\(H_2O\), \(CO_2\) ### Second Sub - Question: Choose all properties that typically apply to ionic compounds.
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which is an example of a monatomic ion? na+ nh4+ co32- no3- so42- a pol…
\( \text{Na}^+ \) (the first option: \( \text{Na}^+ \)) ### Second Question: A polyatomic ion is best described as
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the formula of calcium nitrate, balancing charges of $ca^{2+}$ and $no_…
s: 1. \( \text{Ca(NO}_3\text{)}_2 \) (the last option: Ca(NO₃)₂) 2. \( \text{Na}^+ \) (the first option: Na⁺)
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new and interesting research conducted by suleiman a. a1-sweedan and mo…
A. paucity of
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calculate the bond energy for \c\ in kj. average bond enthalpies (kj/mo…
\(1806\) kJ/mol
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module 8 assessment, ps1 - 2 (ps1 - 7) unit 2 ubuntu, the unsafe scient…
6) b. \(H_2O(l)\) 7) b. Water is a liquid and has two hydrogens and one oxygen. 8) b. \(NaOH(aq)\) 9) a) \(1+\) ion and a) \(1-\) ion 10) \(2Na(s)+2H_2O(l) ightarrow 2NaOH(aq)+H_2…
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you see a liquid seeping out of a container. could this be a visual sig…
Yes
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you see a faint mist hovering above a work area. could this be a visual…
Yes
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revising an explanation three complete chemical reactions are given to …
1. c. \(NaCl(aq)\) 2. a. Sodium chloride dissociates in water and becomes aqueous. 3. d. \(AgNO_3(aq)\) 4. a) 1 + ion and nitrate makes a) 1 - ion
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sal drew the electron dot diagram of an aluminum atom as shown. how sho…
He should add a single dot below the symbol.
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chemical a and chemical b react in an exothermic reaction. what can be …
B. More energy will be released from the old substance than the new substance will release to form its chemical bonds.
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4. explain how ionic compounds with polyatomic ions are both ionic and …
Ionic compounds with polyatomic ions have ionic bonds between the polyatomic ion (as a whole) and the other ion (cation or anion). Within the polyatomic ion, there are covalent bo…
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the first model of the atom was developed through ○ scientific experime…
C. thinking about the smallest particles of matter without experimenting.
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which clue can be used to identify a chemical reaction as a decompositi…
The reaction has a single reactant.
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chemistry i part b: ionic vs covalent review fill in the following sent…
1. Ionic 2. Similar Electronegativities 3. Positively; Losing 4. Negatively; Gaining 5. Cations 6. Anions 7. Electrostatic Attraction 8. Poor 9. Covalent 10. High 11. Dissolve 12.…
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which physical method can be used for obtaining a sample of salt from a…
A. boiling
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what are the products of the combustion of a hydrocarbon? carbon and ox…
B. carbon dioxide and water
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the elements in group 17 of the periodic table are all called halogens.…
number of valence electrons.
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the statue of liberty is made out of copper and was once shiny and copp…
C. a chemical reaction
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which substance is a mixture? table salt gasoline aluminum carbon dioxi…
B. gasoline
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chemistry i part b: ionic vs covalent review fill in the following sent…
1. Trinitrogen tetraphosphide 2. \(NaCl\) 3. \(CO\) 4. Lithium carbonate 5. Ammonium chloride 6. Oxygen dibromide 7. \(FeBr_3\) 8. \(AuI\) 9. Iron (II) oxide 10. \(ZnS\) 11. \(P_2…
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the diagram shows heat being removed from the substance, causing a. it …
A. it to form a liquid as its particles move closer together
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question 19 (4 points) light exposure therapy sparks activity in a brai…
Question 19: The body's arousal Question 20: Drug therapies
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molecular motion is a measure of the movement of the molecules in a sub…
C. soda, air
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molecular motion is a measure of the movement of the molecules in a sub…
C. soda, air
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who is known as the \father of modern chemistry\ because he first organ…
B. Antoine Lavoisier
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who described atoms as small spheres that could not be divided into any…
B. Dalton
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what are the two parts of an atom? the nucleus and the proton cloud the…
D. the nucleus and the electron cloud (assuming the last option is labeled D; if labels were A - D as typical, with the last option being D, the answer is D. the nucleus and the e…
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which best describes a radioactive isotope? an atom is unstable. an ato…
A. An atom is unstable.
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an atom of lithium (li) forms an ionic bond with an atom of chlorine (c…
D. Electrons are transferred from the lithium atom to the chlorine atom.
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which are the products in the equation ( ch_{3}sh + 4o_{2} \to co_{2} +…
C. $\ce{CO_{2}}$, D. $\ce{SO_{2}}$, E. $\ce{H_{2}O}$
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the current model of the atom is 100% correct, and we know everything t…
False
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which symbol in a chemical equation separates the reactants from the pr…
A. =
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multiple - choice question the quantum model is also known as which of …
The electron cloud model.
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multiple - choice question what is an orbital? a large electron. an orb…
C. A region of space that an electron may be found.
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which can occur in a physical change? the mass can increase. the partic…
The particles can arrange in different ways.
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eugene describes the physical property of a material as \sweet and flor…
odor
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question 1 of 10 an engineer that designs buildings is a(n)____. a. civ…
A. civil engineer
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water is made of two hydrogen atoms and one oxygen atom bonded together…
Atoms remain bonded to each other in physical changes.
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serena is mixing a material into a beaker filled with a liquid. she not…
solubility
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what is an example of a physical change? having less ash than the paper…
Ice forming and then melting back into water.
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question 10 of 10 which of the following is a characteristic of the act…
A. They are all radioactive.
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question 9 of 10 which of the following is an alkali metal? a. lithium …
A. Lithium (Li)
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which statement about the physical change of liquid water boiling into …
The heat added represents an energy change.