Chemistry
Chemical reactions, stoichiometry, molecular structures, and element properties.
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a chemical change is different from a physical change because in a chem…
A chemical change is different from a physical change because in a chemical change a new substance is formed and in a physical change a new substance is not formed.
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label the reactants and products in the chemical equation shown. drag l…
\(P_4 + 3O_2\) (Reactants), \(2P_2O_3\) (Products)
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what are the correct coefficients to balance the above chemical equatio…
\(1,5,3,4\)
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reactants are always on the side of the arrow and products are always o…
First blank: left, Second blank: right
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examine the chemical equation. which indicator(s) of a chemical change …
Formation of water, Formation of a gas
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without balancing the final equation, predict the products for the synt…
\(LiCl\)
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which chemical reaction always starts with a hydrocarbon reacting with …
Combustion
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what type of reaction is h₂ + n₂ → nh₃?
Synthesis
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the dissolution of iced tea powder in water is
A. not a chemical reaction
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___h₂o₂ → ___h₂o + ___o₂ it is already balanced 2,2,1 2,1,2 2,1,1
\(2H_2O_2 ightarrow2H_2O + 1O_2\)
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true or false: when balancing chemical equations, can you change the su…
False
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without balancing the final equation, predict the products for the synt…
\(MgBr_2\)
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estion 11 (3 points) listen the above image shows the aftermath of soli…
A chemical reaction has taken place because a gas (carbon dioxide) is formed, which is indicated by the bubbling and fizzing in the mixture.
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question 10 (3 points) listen helium atom what happens to this atom if …
1. The atom changes from helium to hydrogen (as the number of protons determines the element). 2. The atom (now a hydrogen - related species) may become negatively charged (\(H^-\…
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which glass shows a homogeneous mixture and which shows a heterogeneous…
The glass with sugar and water shows a homogeneous mixture because sugar dissolves uniformly in water. The glass with sand and water shows a heterogeneous mixture because sand doe…
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look at the picture showing a piece of wood burning in a fire. which op…
The wood is changing into new substances like ash, heat, and smoke.
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ionic vs. covalent bonding ionic bond covalent bond which is true regar…
Ionic bonds happen when atoms give or take (transfer) electrons.
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how can land pollution harm the environment? * it can allow for harmful…
B. All of the above
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metals, nonmetals, and metalloids which statement is true about the per…
Elements in the same group or column have similar properties.
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observe the picture above. what changes between isotopes? atomic number…
Number of neutrons
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observe the picture above and answer the questions below: if an atom lo…
It becomes positively charged (cation +2)
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15. which of the following is a source of nonpoint pollution? * a. unli…
15. d. runoff from agricultural fertilizers 16. a. pathogen 17. c. water conservation
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balancing equation mixed review 7. rxn type: ___ + ___ → ___ therefore …
7. \(1\ CaO+1\ H_2O \to 1\ Ca(OH)_2\), Syn 8. \(2NaF + 1Br_2\to2NaBr+1F_2\), SR 9. \(2Al + 6HCl\to3H_2+2AlCl_3\), SR 10. \(4Cu+1O_2\to2Cu_2O\), Syn
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the orange, round particles you see represent h+ ions in solution. whic…
All of these statements are true
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look at the picture showing ice, liquid water, and steam. which stateme…
In solids, particles are tightly packed and only vibrate; In liquids, they move around each other; In gases, they move freely and spread out.
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calculate the volume in liters of a ( 8.61\times10^{-4} ) mm copper(ii)…
\(1.03\times 10^{4}\space L\)
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a chemist adds 370.0 ml of a 1.7 mol/l iron(iii) bromide (febr₃) soluti…
\(0.19\space kg\)
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which particles account for nearly all of the mass of the atom? a proto…
B. protons and neutrons
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24 select the correct answer. at work, claire has a deadline that is ra…
A. chemicals associated with short - term stress
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calculate the volume in milliliters of a 1.67m aluminum chloride soluti…
\(674\)
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which of the following correctly describes a proton? a it has an electr…
d. none of the above
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a chemist must prepare 225. ml of 220. mm aqueous barium chlorate (ba(c…
\(176\space mL\)
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a chemist makes 200. ml of copper(ii) fluoride (cuf₂) working solution …
\(1.92\space mM\)
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a chemist must dilute 83.1 ml of 5.24 m aqueous iron(ii) bromide (febr₂…
\(0.218\space L\)
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atoms of different i can be distinguished from each other by the number…
Elements
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which variables have a direct effect on movement in chromatography? che…
Solubility of pigment, Size of pigment
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keeping in mind that a sample moves with the solvent, is it possible to…
No
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the solvent in paper chromatography is also known as the _ phase. fill …
mobile
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the paper in paper chromatography is also known as the phase. fill in t…
stationary
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is the dye that will allow us to see the amino acids in paper chromatog…
Ninhydrin
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another name for separation in column chromatography is_________. fill …
elution
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a chemist prepares a solution of silver oxide (ago) by weighing out 5.1…
\(2.0\times 10^{-3}\space g/dL\) (rounded to two significant digits as \(5.10\) has three significant digits and \(250\) has two significant digits, and in division, the result is…
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a chemist prepares a solution of barium chlorate (ba(clo₃)₂) by weighin…
\(298\space g/L\)
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a chemist prepares a solution of copper(ii) sulfate (cuso₄) by weighing…
\(93.3\space g/L\)
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a chemist prepares a solution of mercury(ii) iodide (hgi₂) by weighing …
\(0.0306\ \text{g/L}\)
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2 in column chromatography, the _ is the membrane that allows water to …
frit
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1 what allows molecules be separated by column chromatography? check al…
Shape, Size, Polarity
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match the definition with the word: control dependent variable independ…
7. Proton 8. Dependent variable 9. Independent variable 10. Atom 11. Control 12. Nucleus
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an unknown metal in the lab weighs 48.1 grams. it absorbs 575 j of heat…
Ag
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consider the following thermochemical equation: h₂(g) + cl₂(g) → 2 hcl(…
+184.6 kJ
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consider the following thermochemical equation: 2 nh₃(g) → n₂(g) + 3 h₂…
121 kJ
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copper metal has a specific heat of 0.385 j/g·°c. calculate the amount …
7.51 kJ
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what is the change in internal energy, \\( \\delta u \\), in joules, fo…
+ 160 J
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which equation represents the standard enthalpy of formation, \\( delta…
$\frac{1}{2}H_2(g)+\frac{1}{2}N_2(g)+O_2(g)\to HNO_2(aq)$
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what is the change in internal energy, \\( \\delta u \\), in joules, fo…
+ 160 J
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estimate the enthalpy change for the reaction ( c_{2}h_{4}(g)+h_{2}(g)\…
-119 kJ
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calculate \\( \\delta h^{\\circ} \\) for the reaction shown below given…
-282.6 kJ (the option corresponding to this value in the given multiple - choice list)
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given: $so_{2}(g)+\frac{1}{2}o_{2}(g)\to so_{3}(g) delta h^{circ}=-99 k…
+198 kJ
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how much heat is evolved when 320 g of so₂ is burned according to the c…
\(495\space kJ\) (the fifth option)
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copper metal has a specific heat of 0.385 j/g °c. calculate the amount …
7.51 kJ
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question 24 of 25 enter the answer to the problem below, using the corr…
\(33\)
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3. draw the lewis structure for the no3^- ion. a) draw all resonance st…
a) The resonance structures of \(NO_{3}^{-}\) are as follows (showing the movement of double bond among the three \(O\) atoms around \(N\)). b) In one resonance structure (e.g., \…
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calculate the amount of heat needed, in kj, to heat 7.8 g of water from…
$1.31kJ$
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determine the amount of heat, in kj, given off when 211 g of no₂ is pro…
\(-263\ kJ\)
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determine the amount of heat, in kj, given off when 211 g of no₂ is pro…
\(-263\ kJ\)
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determine the amount of no₂ produced, in g, if -744 kj of heat is given…
$597$
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choose the sentence which corrects the incorrect omission in the follow…
Astronomers on the whole understand the solar system better than chemists do.
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which of the following is a compound - complex sentence? while at schoo…
After we get done with school, I have to go to work, but Luther has to go to practice.
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which of the following are common design elements found in persian carp…
floral patterns and geometric designs
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cross charges to form an ionic compound. write the correct chemical for…
1. \(LiCl\) 2. \(BaS\) 3. \(Na_{2}O\) 6. \(AlN\) 7. \(Na_{2}S\) 8. \(BaO\)
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18 when water evaporates, it changes into a a solution b solid c mixtur…
D. gas
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every chemical compound has a spectroscopic fingerprint, a pattern of r…
C. Thus.
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(solids, liquids, gases) most substances go through a phase change when…
1. Freezing 2. Melting 3. Vaporization 4. Condensation 5. E and F 6. Temperature increases (from solid to liquid for E: \(0^{\circ}C\) to \(0 - 100^{\circ}C\); from liquid to gas …
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calculate the amount of heat, in kj, associated with 169 g of mercury c…
$-1.08kJ$
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3. suppose that during the icy hot lab that 65 kj of energy were transf…
\( 55^{\circ}C \)
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determine the amount of heat, in kj, given off when 329 g of no₂ is pro…
\(-410\space kJ\)
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determine the amount of no₂ produced, in g, if -200 kj of heat is given…
$160$
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7. what is unique per each atom that determines which element it is?
The number of protons (atomic number)
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question 9 of 15 how many significant figures will the answer to the fo…
\(3\)
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1. a molecule has 2 double bonds on the central atom and no lone pairs.…
- Electron geometry: Linear - Molecular geometry: Linear - Bond angles: \(180^{\circ}\)
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question 8 of 15 match each expression to the correct number of signifi…
\(13.115 + 4.90255\) matches \(5\); \(1200\) matches \(2\); \(3000\) matches \(1\); \(200.12 - 4.9\) matches \(4\)
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what will be the final temperature, in °c, of a 373 - g sample of water…
\(65.3^{\circ}C\)
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question 1 of 15 match each expression to the correct number of signifi…
185.3 → 4; 0.06 → 1; 1,760 → 3; \(55 + 7.1\) → 3
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b. non - bonding electrons/lone pair electron domains are typically loc…
Water (\(H_2O\)) has two lone pairs on the central atom, while ammonia (\(NH_3\)) has one. The extra lone pair in \(H_2O\) causes stronger repulsion, resulting in a larger differe…
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calculate the amount of heat, in kj, associated with 212 g of mercury c…
\(-3.40kJ\)
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a. what structural feature seems to distinguish the molecules where the…
Molecules with lone pairs of electrons on the central atom have real bond angles less than model bond angles.
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what is a type of contaminant that can cause foodborne illness? chemica…
parasites
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according to the us food and drug administration (fda) what must any pr…
at least 95% organically produced ingredients
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determine the amount of heat, in kj, given off when 186 g of no₂ is pro…
\(-231\)
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question 9 determine the amount of no₂ produced, in g. if -622 kj of he…
\(500\)
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14. considering that all electrons are negatively charged, do the bondi…
Repulsive forces.
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a group of lines in poetry is called rhyming rhyme scheme verses a stan…
a stanza
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12. sometimes the molecular geometry and the electron geometry are the …
The Molecular and Electron geometry of a molecule are the same when there are no lone pairs of electrons on the central atom. The Molecular geometry differs from the Electron geom…
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in a liquid, the particles are ____?____ as compared to solids, so they…
not as tightly packed, free to move around
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what will be the final temperature, in °c, of a 421 - g sample of water…
\(57.1^{\circ}C\)
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question 13 calculate the amount of heat, in kj, associated with 127 g …
\(-0.88kJ\)
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3. fill in the electronegativity for the following elements. you will h…
- **Across a period**: Electronegativity generally increases (e.g., for Ga (1.81), Ge (2.01), As (2.18), Se (2.55), Br (2.96) in period 4, ignoring the noble gas Kr as a special c…
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determine the amount of no₂ produced, in g, if -552 kj of heat is given…
\(443\space g\)
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the properties of gases depend on... the amount present in the sample h…
the amount present in the sample, the mass of the sample
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question 9 determine the amount of heat, in kj, given off when 258 g of…
\(-321\)