化学
化学反应、化学计量、分子结构与元素性质。
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why should you only handle a clean crucible with crucible tongs? the cr…
Question 1: You do not want to contaminate the crucible with oils on your fingers or particles on your gloves Question 2: Magnesium burns brightly enough to cause temporary blindn…
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how can understanding that theories and laws operate consistently over …
It shows that chemical reactions follow consistent rules defined by those theories and laws.
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which change is chemical? (1 point) water evaporating: liquid water bec…
water undergoing electrolysis: liquid water becoming oxygen and hydrogen molecules
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what is the activation energy of a reaction? (1 point) o the amount of …
the minimum energy required by the reactants for the reaction to proceed
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challenge 2 ? element name: ? element symbol: ? mass number: 5 ? # of p…
Element Name: Boron Element Symbol: B Mass Number: 5 # of Protons: 5 # of Neutrons: 0 # of Electrons: 5 Charge: 0 Ion?: No (Neutral Atom) Stable?: Yes
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element name how many? 2 p+ 3 n° 2 e- how many stable isotopes of this …
Element Name: Helium Symbol: $He$ Number of stable isotopes: 2
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if you change the number of electrons... mass #: stays constant changes…
Mass #: Stays Constant Charge: Changes Atom Name (Identity): Stays Constant
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practice make the atoms. fill in the missing information: carbon elemen…
Check the "Stable" box.
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if you change the number of electrons... mass #: stays constant, change…
Mass #: Stays Constant Charge: Changes Atom Name (Identity): Stays Constant Element Name: Boron Element Symbol: B Mass Number: 5 # of Protons: 5 # of Neutrons: 5 # of Electrons: 5…
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scenario 2: the acidity of different types of pop was investigated by p…
IV: Type of pop DV: Amount of corrosion Cons: Identical nails, time - intervals of checking
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using the data above, or by adding/subtracting the p if you change the …
If you change the number of protons: - Mass #: Changes - Charge: Changes - Atom Name (Identity): Changes If you change the number of neutrons: - Mass #: Changes - Charge: Stays Co…
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which atom is a carbon atom?
C
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which statement best explains why carbon is present in so many kinds of…
Question 1: It can form four covalent bonds Question 2: A fundamental role
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identify the independent variable in the following scenario: im trying …
The brand of coffee (Starbucks or Dunkin)
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1. classify the following as heterogeneous or homogeneous mixture. salt…
Homogenous
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9. identify the figurative language in line 13. 10. what do the words “…
9. Cannot be determined without line 13. 10. A noisy, crowded, chaotic situation. 11. To move quietly and stealthily. 12. A period of powerlessness. 13. Free - flowing and spontan…
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apply the big idea read the activity in the left column. then, in the r…
- Prepare for a career: A chemist developing drugs in a pharmaceutical company. - Act as an informed citizen: Deciding on a local chemical - plant expansion. - Use technology: Sel…
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select the correct answer. which event represents a chemical change? a.…
D. milk turning sour
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in the image, balls that look alike represent the same type of atom. ba…
B. molecules of elements
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select the correct answer. what happens to the molecules within a gas w…
B. They lose energy
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during which processes does the space between particles tend to increas…
Melting and vaporization
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the mass number is the protons added together with the: neutrons electr…
Neutrons
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if an element has 7 protons in the nucleus, how many neutrons will be p…
7
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consider the reaction h₂(g) + i₂(g) ⇌ 2hi(g). what is the reaction quot…
613
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a solid reactant is placed into a beaker of a warm water. the liquid vi…
Fewer bubbles will be produced because of fewer collisions of reactant molecules.
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which of the following best defines an acid? an acid has a ph of 7. an …
An acid has more hydrogen ions in solution.
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which statement correctly compares chemical reactions with nuclear reac…
In chemical reactions, small amounts of energy can be absorbed or released. In nuclear reactions, changes in energy are much larger.
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the following half - reaction method is used to balance oxidation - red…
Balance the half reactions based on the number of electrons
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a scientist researching methods to convert used motor oil into gasoline…
B. breaking molecules into smaller chains
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four substances are tested for different properties. the results of the…
Z
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the following reaction occurs in a cars catalytic converter. 2no(g) + 2…
The oxidation state of nitrogen in NO changes from +2 to 0, and the oxidation state of carbon in CO changes from +2 to +4 as the reaction proceeds.
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ca(oh)₂ is added to a large beaker of water. how is the solution differ…
The solution turns phenolphthalein pink.
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which of the following is an oxidation - reduction reaction? o so₂(g) +…
$C_6H_{12}O_6(s)+6O_2(g)\longrightarrow 6CO_2(g)+6H_2O(l)$
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arrange the events involved in the formation of coal in the order they …
1. Plants and trees inhabited the land and the seas about 300 million years ago. 2. Organisms died and were buried on the ocean floor and in swampy areas. 3. Layers of silt and sa…
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ethylene, a gas found in nature, is commonly used to ripen bananas and …
The third option with the structure having a carbon - carbon double bond ($C = C$) and four hydrogen atoms attached to the carbon atoms.
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the molar mass of naoh is 40.00 g/mol. if 5.20 g naoh are dissolved in …
B. 0.260 M
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which of the following shows a bronsted - lowry acid reacting? co + no2…
$HCl + H_2O ightarrow H_3O^+ + Cl^-$
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consider the following reversible reaction. c(s)+o₂(g)⇌co₂(g) what is t…
$K_{eq}=\frac{[CO_2]}{[O_2]}$ (the second option)
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select the correct text in the passage. which sentence incorrectly desc…
In such conditions, oxygen was available in abundance.
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question 1 match the following chemical bond to the correct organic mol…
Glycosidic Linkage: Carbohydrate Ester Linkage: Lipid Peptide Bond: Protein Phosphodiester bond: Nucleic Acid
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consider the hydrocarbon below. what is the name of this hydrocarbon? 1…
B. 1 - pentyne
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select the correct answer from the drop - down menu. ammonia is a gas m…
a compound
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a student requires 2.00 l of 0.100 m nh4no3 from a 1.75 m nh4no3 stock …
Measure 114 mL of the 1.75 M solution, and dilute it to 2.00 L.
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water is dissolved into n - butanol (a polar liquid). which is the seco…
n-Butanol molecules surround water molecules.
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what is a common use of bases? as a component of vinegar as a component…
to reduce indigestion
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according to the collision theory, which is required for a high number …
molecular collisions with energy to overcome activation energy
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which value is most likely to be the ph of a salt solution that is form…
A. 2.0
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which value is most likely to be the ph of a salt solution that is form…
D. 8.7
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which molecule shown in the figure is a thiol? a. h h h c n h h h b. h …
B.
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consider the following system at equilibrium. caco₃(s) ⇌ ca²⁺(aq) + co₃…
D. $Na_2CO_3$
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which functional group is not present in this molecule? ho c o h h - c …
Sulfhydryl
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pure water at 25°c ionizes in the presence of acid to form an equilibri…
self - ionizes to form an equilibrium in which $[H_3O^+]=[OH^-]=10^{-7}M$
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the reaction of a lewis acid with a lewis base would most likely be acc…
covalent bonds
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a beam of light passes though a liquid in a test tube without scatterin…
C. solution
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select the correct location on the image. which number gives the atomic…
196.966569(4)
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which term describes this reaction? oh h2so4 heat addition condensation…
C. elimination
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select the correct answer. what do these images model? a. atoms b. comp…
B. compounds
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which best describes the functional group in an aldehyde? a carbonyl gr…
a carbon chain with a carbonyl group bonded to one end
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which best describes the function of a centrifuge? to separate the solu…
to separate the undissolved particles of a mixture into layers
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how much of a sample remains after five half - lives have occurred? 1/5…
C. 1/32 of the original sample
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ethanol, an organic compound, has the following structural formula. wha…
D. $C_{2}H_{6}O$
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which best explains the formation of polyester? a condensation polymeri…
a condensation polymerization of a carboxylic acid and an alcohol
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a 60.0 - g sample of fermium - 253 was placed in a sealed vessel 9.0 da…
A. 3.0 days
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consider the chemical reaction in equilibrium. h₂ + i₂ + heat ⇌ 2hi. wh…
The direction of the chemical equilibrium will shift to the right, favoring the forward reaction.
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which class of organic compound would neutralize a carboxylic acid? ald…
B. amine
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in an experiment, a student wants to increase the rate of a reaction th…
Decrease the volume to increase pressure and to increase concentration.
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which best describes why acetic acid (ch₃cooh) is an organic compound, …
Acetic acid contains a significant amount of carbon, but sodium hydroxide contains no carbon.
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21 multiple choice 1 point which gas is least soluble at 10 °c? o nacl …
D. CO₂
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the poh of a solution is 6.0. which statement is correct? use poh = -lo…
The pH of the solution is 8.0.
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20 multiple choice 1 point which salt is least soluble at 10 °c? nacl n…
C. $KClO_3$
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19 true or false 1 point in a solubility curve graph, you will notice t…
False
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consider the redox reaction below. 2al(s) + 6hcl(aq)→2alcl3(aq)+3h2(g) …
Aluminum is oxidized from 0 to +3.
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18 multiple choice 1 point which salt has the greatest increase of solu…
NaNO₃
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1. a chemical change is shown in the picture below. name three signs th…
1. Color change, formation of a new substance, non - reversibility. 2. Glass (a) likely contains a dissolved mixture. In the dissolved mixture, particles are molecular/ionic and e…
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a chemistry journal requires that all new research papers be peer revie…
The reviewers can determine the experiment's validity.
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kclo3 how many grams of kclo3 will dissolve in: note: remember that the…
12 g
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which is the first step in the dissolving process? the solute becomes l…
The solvent molecules are attracted to particles at the surface of the solute.
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kclo3 how many grams of kclo3 will dissolve in: note: remember that the…
24 g
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kclo3 how many grams of kclo3 will dissolve in: note: remember that the…
28 g
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an atom bonds with another atom. what is the best classification for th…
chemical
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kclo3 how many grams of kclo3 will dissolve in note: remember that the …
7 g
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consider the half reactions below for a chemical reaction. mg → mg²⁺(aq…
$Mg(s)+2H^{+}(aq) ightarrow Mg^{2 +}(aq)+H_{2}(g)$ (corresponds to the first option in the multiple - choice)
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the molecule acetylene (c₂h₂) has hybridization, resulting in a linear …
sp
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13 fill in the blank 1 point a saturated solution of kcl at 90 °c is co…
25 g
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12 fill in the blank 1 point to what temperature must a solution of 50 …
85°C
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a molecule with sp³d hybridization has a bipyramidal geometry.
trigonal
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11 fill in the blank 1 point how many grams of pb(no₃)₂ can be dissolve…
255 g
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sp hybridization results in a geometry with a bond angle of 180°.
linear
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key concept check 1. contrast: what is the difference between chemical …
Physical properties can be observed or measured without altering the substance's chemical composition. Chemical properties involve the substance's ability to undergo chemical reac…
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key concept check 1. contrast: what is the difference between chemical …
A physical change only affects physical properties like state, shape, etc., without changing the chemical makeup of a substance. A chemical change results in the formation of new …
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which compound is used to make asphalt? a saturated hydrocarbon that ha…
a saturated hydrocarbon that has more than 35 carbons in its chain
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elimination substitution addition polymerization condensation polymeriz…
C. addition polymerization
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what is a characteristic of straight chained alkanes? they have one or …
They have carbons bonded in a single row from one end of the molecule to the other end of the molecule.
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which hybridization type involves the mixing of one s orbital, three p …
C. sp³d
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in which reaction is a small molecule formed from the atoms removed fro…
C. elimination
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d. flammability is a chemical property reading check 1. explain: how do…
1. At the melting point, a material changes from solid to liquid. At the boiling point, it changes from liquid to gas. 2. Flammability.
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a plastic that is composed of a saturated hydrocarbon would have molecu…
A. asphalt
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trevor watches as a freight train passes. he counts eight identical bla…
an alkyl halide
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answer the questions in the table below about this molecule: what is th…
What is this molecule's chemical formula? $C_{3}H_{8}O$ How many $CH_{3}$, $CH_{2}$, and $CH$ groups are in this molecule? 2 $CH_{3}$, 0 $CH_{2}$, 1 $CH$
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what is the general formula for a secondary amine? rnh₂ h₂nrnh₂ rn₂h r₂…
$R_2NH$