化学
化学反应、化学计量、分子结构与元素性质。
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how does waters polar structure impact its ability to form solutions wi…
None of the provided options are completely correct. But if we assume the last option was meant to say "allowing water to wedge between other polar molecules and break them down, …
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which type of molecules is water good at dissolving? large molecules sm…
C. Polar molecules
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diffusion works best with... particles trapped in limited space. partic…
moving particles suspended freely in a solution.
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which of the following is not an example of a solution? bowl of cereal …
Bowl of cereal
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what is a solution? a mixture with only one type of substance evenly di…
B. A mixture in which the molecules of one substance are evenly distributed within another substance
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how does diffusion work when air freshener is sprayed in a room? all of…
All of these answers are correct.
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a solute is... the part of a solution that is dissolved. the part of a …
the part of a solution that is dissolved.
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what is a solution? a mixture in which the molecules of one substance a…
A. A mixture in which the molecules of one substance are evenly distributed within another substance
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which type of molecules is water good at dissolving? polar molecules sm…
Polar molecules
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how does waters polar structure impact its ability to form solutions wi…
Water is attracted to other polar molecules, allowing water to wedge between other polar molecules and break them down, forming a solution.
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a polar molecule is best described as... none of these. a molecule that…
having positive and negative ends.
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complete the following questions using your periodic table. if you have…
1. The number of protons in the nucleus of an atom. 2. The total number of protons and neutrons in the nucleus of an atom. 3. An atom of an element with the same atomic number but…
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7) which is larger? a) atomic mass b) atomic number
a) Atomic Mass
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6) in a neutral atom, the atomic number is equal to the number of selec…
A. Electrons, C. Protons
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5) how many protons, neutrons, and electrons should be included in the …
B. 7 protons, 7 neutrons, and 7 electrons
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4) the periodic table organizes elements into columns called groups. fo…
C. They are grouped in a column because they have similar properties
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2) a carbon atom is shown in the model. based on the model, which state…
d) They are smaller than the other particles and are modeled predictably around the center.
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1) a student in science class is creating a key to classify different t…
a) Element b) Compound c) Mixture
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how does the mass, or heaviness, of a particle affect the rate of diffu…
C. Lighter particles typically diffuse faster than heavier particles.
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how does diffusion work when air freshener is sprayed in a room? the ai…
B. All of these answers are correct.
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which of the following do lewis structures help us understand? the exac…
the number of electrons that are involved in the bonding of the molecule
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which of the following could form an ionic bond with an anion? hg₂²+ no…
$\boldsymbol{\ce{Hg^{2+}_{2}}}$
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which best describes why nh₄⁺ can form an ionic bond with cl⁻? its oute…
Its positive charge is attracted to the negative charge of $\ce{Cl^{-}}$.
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what is the chemical formula for copper(ll) sulfate? cuso₄ cu₂so₄ cus c…
A. CuSO₄
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35. draw draw the electron dot structure for each mol-ecule. identify p…
a. Electron - dot structure: \(H:\ddot{O}:\ddot{O}:H\); Polar bonds: \(H\ (\delta+)-O\ (\delta-)\) b. Electron - dot structure: \(\ddot{Br}:\ddot{Cl}\); Polar bonds: \(Br\ (\delta…
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the fluid in a car battery has a volume of 131 ml and a mass of 163 g. …
\( 1.24\ g/mL \)
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determine the number of significant figures in the measurement 0.0030 s…
2
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a 5.23 g sample of a metal occupies 0.27 ml. identify the density of th…
19 g/mL
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balancing equations - #1 a. \\( \\frac{4}{1} \\mathrm{na}+\\frac{1}{2} …
d. \(2Al_2O_3 = 4Al+3O_2\) e. \(N_2 + 3H_2=2NH_3\) f. \(3Fe + 4H_2O=Fe_3O_4+4H_2\) g. \(P_4 + 5O_2=P_4O_{10}\) h. \(2C_2H_6+7O_2 = 4CO_2+6H_2O\) i. \(SiCl_4=Si + 2Cl_2\)
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how many significant figures (sfs) are in each of the following measure…
- \(2\) SFs: \(7.0\times 10^{-3}\text{ L}\) - \(3\) SFs: \(20400000\text{ g}\), \(7.00\text{ m}\), \(80.3^{\circ}\text{C}\) - \(4\) SFs: \(50.40\text{ mL}\) - \(6\) SFs: \(2082.24…
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1. write a definition of the following: a. chemistry b. matter c. atom …
a. Chemistry: The scientific study of matter, its properties, composition, and the changes it undergoes. b. Matter: Anything that has mass and occupies space. c. Atom: The basic u…
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what is meant by the rate of a reaction? the rate of a reaction is the …
Indicates how fast the products are formed or how fast the reactants are consumed.
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in a _________ reaction, two or more elements or compounds form one pro…
combination
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the following reaction is an example of a ___________ reaction. mathrm{…
combustion
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barium chloride and sodium sulfate react according to the following equ…
28 g
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caco₃(s) → cao(s) + co₂(g) express your answer as a chemical equation. …
\(CaCO_3(s) ightarrow CaO(s)+CO_2(g)\)
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k₂so₄(aq) + bacl₂(aq) → kcl(aq) + baso₄(s) express your answer as a che…
$$\text{K}_2\text{SO}_4(\text{aq})+\text{BaCl}_2(\text{aq})\to2\text{KCl}(\text{aq})+\text{BaSO}_4(\text{s})$$
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al(s) + h₂so₄(aq) → al₂(so₄)₂(aq) + h₂(g) express your answer as a chem…
$$2Al(s)+3H_{2}SO_{4}(aq)\to Al_{2}(SO_{4})_{3}(aq)+3H_{2}(g)$$
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zn(s) + hno₃(aq) → zn(no₃)₂(aq) + h₂(g) express your answer as a chemic…
\(Zn(s)+2HNO_3(aq)\to Zn(NO_3)_2(aq)+H_2(g)\)
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what is the simple way of writing a generic combustion reaction? cxhy (…
The third option (\(C_xH_y+O_2 ightarrow CO_2 + H_2O\)) is the correct simple way of writing a generic combustion reaction.
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using the letters a,b,c and d create a model of a double replacement re…
\(AC + BD\to AD + BC\)
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using the letters a,b an c create a model of a single replacement react…
The correct forms of single - replacement reactions are \(A + BC ightarrow B + AC\) and \(A + BC ightarrow AB + C\).
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a student was studying physical and chemical changes. the student carri…
A. A cube of metal was changed into a flat sheet of metal.
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a student was asked to formulate a hypothesis about what would happen i…
C. The resulting solution would contain a precipitate.
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hcl(aq) + naoh(aq) → nacl(aq) + h₂o(l) a student had two dilute, colorl…
B. The temperature of the reaction mixture increases.
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which best describes the advantage of pest resistance? pests can tolera…
Farmers do not have to use harsh chemicals to save their crops.
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in 1939, the use of ddt (a powerful synthetic chemical) as an insectici…
Insect and pest populations decreased
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in parts 2, 3 and 4 of this lab, you will be conducting calorimetry exp…
5.0 g (since the two solutions are mixed together, the volumes and hence their masses are added together).
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in part 1 of this lab, you will be calculating \\( \\delta _ { mathrm {…
Number of moles of magnesium, since \(Mg\) is in the balanced chemical equation and is a part of the system.
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in part 1 of this lab, you will be calculating δrh by conducting consta…
Leave \(T_{initial}\) and \(T_{final}\) in \(^{\circ}C\), then calculate \(T_{final}-T_{initial}\), then leave the result in \(^{\circ}C\) (as we learned in lecture)
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in part 1 of this lab, you will be calculating δrh by conducting consta…
Mass of the aqueous solution, since we are measuring its temperature using the thermometer.
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in this lab you will be calculating $delta_{r}h$ for several chemical r…
Negative, because an increase in temperature means the reaction is exothermic.
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in this lab you are synthesizing acetylsalicylic acid (asa) from salicy…
$1.37$
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describe the difference between mechanical and organic solidarity in yo…
Mechanical solidarity is in simple, like - valued societies. Organic solidarity is in complex, specialized, interdependent ones.
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which type of energy is produced by vibrations traveling in waves? soun…
sound energy
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which of the following is not a pure substance? nitrogen carbon trail m…
trail mix
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a chemical change happens when the molecules in a substance change to p…
toast smells different than bread
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which of the following is not an example of a chemical change? a piece …
a piece of paper being torn
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which household chore is a physical change? cooking dinner folding laun…
B. Folding laundry
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the atomic number is the number of protons in the nucleus. which elemen…
B. Rhenium
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which of the following best describes an ion? an atom that is neutral a…
an atom that is charged
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which is a characteristic of metals? brittle insulative malleable
malleable
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particle models below are three particle models illustrating different …
model B
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sep construct an explanation from which area of the periodic table are …
Semiconductors are likely to be found near the zig - zag line (metalloid region) of the periodic table. This is because elements in this area (such as silicon and germanium) have …
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sep use models when and if element 119 is discovered, predict where it …
Element 119 would be placed in period 8, group 1 of the modern periodic table.
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where is there a low concentration of due? no concerteraion gradient at…
at the top of cup
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ccc patterns how is the process of using patterns to predict phases of …
Both use pattern - recognition. Moon phase prediction uses the cyclical lunar pattern. Mendeleev used atomic mass and property patterns in the periodic table to predict elements.
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1) please name the following compounds: a. b. c. d. e.
a. 2,4 - dimethyl - 3 - pentanone b. 2 - hydroxy - pentanal c. 4 - chloro - hexanal d. 2 - isopropyl - 4 - bromomethyl - 3 - pentanone e. 1,1 - dimethyl - cyclopentanone
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select the correct answer. the chemical composition of most stars usual…
B. hydrogen
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a safe holiday feast infographic by the partnership for food safety edu…
Buy a food thermometer.
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\a safe holiday feast\ infographic by the partnership for food safety e…
Perishable food must be refrigerated as soon as you get home.
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what is true about shape in our environment in terms of what was learne…
Shapes in our environment are ubiquitous and found in all aspects of our daily lives, from natural objects to man - made structures.
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material properties and changes cloze materials can be described by the…
Materials can be described by their properties such as hardness, transparency and thermal or electrical conductivity. Some materials will dissolve in liquids to form solutions. Se…
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which are characteristics of carbon? check all that apply. covalent bon…
covalent bonding, generally in nonelectrolytes, low melting point, forms a variety of compounds
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why do atoms form ions? to achieve 8 valence electrons to lose all of t…
To achieve 8 valence electrons.
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which represents the ion formed when aluminum achieves a full valence s…
C. \(Al^{3+}\)
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polyatomic ions 16. no₃⁻ → 17. so₄²⁻ → 18. co₃²⁻ → 19. oh⁻ → 20. nh₄⁺ →
16. nitrate ion 17. sulfate ion 18. carbonate ion 19. hydroxide ion 20. ammonium ion
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why dont the elements in group 4 gain or lose electrons? both of these …
A. Both of these reasons
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oxyacids 6. hno₃ → nitric acid 7. hno₂ → nitrous acid 8. h₂so₄ → sulfur…
Chloric acid
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what is the difference between a bromine atom and a bromine ion? a brom…
C. A bromine atom has 35 electrons, while a bromine ion has 36 electrons.
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why dont the elements in group 4 gain or lose electrons? both of these …
Both of these reasons
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predict the products of the following reaction. if no reaction will occ…
\(C_3H_4(g)+4O_2(g)\to 3CO_2(g)+2H_2O(g)\)
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classify each chemical reaction: 2ch₃ch₂co₂h(l) + 7o₂(g) → 6co₂(g) + 6h…
- \(2CH_{3}CH_{2}CO_{2}H(l)+7O_{2}(g)\to6CO_{2}(g)+6H_{2}O(g)\): combustion - \(MgI_{2}(aq)+Pb(NO_{3})_{2}(aq)\to Mg(NO_{3})_{2}(aq)+PbI_{2}(s)\): double replacement, precipitatio…
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classify each chemical reaction: 2al(s) + 3znbr₂(aq) → 2albr₃(aq) + 3zn…
1. single displacement 2. double substitution 3. combination 4. decomposition
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look at these two molecular diagrams and think about the features of th…
- are isomers of each other - have same molecular formula - are both hydrocarbons - have same number of each kind of atom
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for each reaction, write the chemical formulae of the oxidized reactant…
- For \(Ca(s)+ZnCl_2(aq)\to Zn(s)+CaCl_2(aq)\): - reactants oxidized: \(Ca\) - reactants reduced: \(ZnCl_2\) - For \(Zn(s)+2AgNO_3(aq)\to Zn(NO_3)_2(aq)+2Ag(s)\): - reactants oxid…
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which descriptions apply to isomers? check all that apply. same molecul…
same molecular formula, different structural formula, same number of each kind of atom
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in a certain chemical, the ratio of zinc to copper is 3 to 11. a jar of…
\(147\)
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4. how does age influence dietary needs? it does not affect dietary nee…
- 4. Nutritional needs vary significantly across different stages of life. - 5. Emotions can drive people to eat even when they're not hungry. - 6. Lower income may limit access t…
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4 why is monitoring sodium intake important according to nutrition labe…
4. It helps regulate blood pressure and fluid balance. 5. The nutrient contribution to a daily diet. 6. Vegan label.
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if a solution is undergoing a reaction where co₂ is being created a pro…
yellow
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for each reaction in the table below, write the chemical formulae of an…
| reaction | reactants oxidized | reactants reduced | |--|--|--| | \(Pb(s)+2Cl_{2}(g)\to PbCl_{4}(s)\) | \(Pb\) | \(Cl_{2}\) | | \(O_{2}(g)+Cr(s)\to CrO_{2}(s)\) | \(Cr\) | \(O_{2…
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how does a phenol red - containing solution look if co₂ level is high? …
yellow
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this painting is by pablo picasso, entitled the blind mans meal. what t…
B. He used a monochromatic color scheme, which occurs when one color predominates, shades of black, tints of white, values of a hue.
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some chemical reactants are listed in the table below. complete the tab…
| species | oxidation state of highlighted atom | | ---- | ---- | | \(H_3O^+(aq)\) | \(-2\) | | \(CO_3^{2-}(aq)\) | \(+4\) | | \(CrO_4^{2-}(aq)\) | \(+6\) | | \(HCO_3^{-}(aq)\) | …
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some chemical reactants are listed in the table below. complete the tab…
| species | oxidation state of highlighted atom | | ---- | ---- | | \(N_2(g)\) | \(0\) | | \(Br^-(aq)\) | \(-1\) | | \(Na^+(aq)\) | \(+1\) | | \(Cu^+(aq)\) | \(+1\) |
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you do: 1) no₂ and co₂ have a similar molecular weight. which gas would…
$\ce{NO2}$ would be predicted to deviate more from an ideal gas. This is because $\ce{NO2}$ has stronger intermolecular forces (such as dipole - dipole interactions and potential …
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how does a phenol red - containing solution look if co₂ level is low? m…
red
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predict the products of the reaction below. that is, complete the right…
\( 2\text{HCl}+\text{Ca(OH)}_2 ightarrow\text{CaCl}_2 + 2\text{H}_2\text{O}\)
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the following chemical reaction takes place in aqueous solution: 2agno3…
$$2Ag^{+}(aq)+CO_{3}^{2 - }(aq)\to Ag_{2}CO_{3}(s)$$