Química
Reacciones químicas, estequiometría, estructuras moleculares y propiedades.
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endorphins can reduce the perception of sensations initiated by nocicep…
nociceptors.
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free nerve endings detect which stimulus/stimuli? pain only chemicals o…
temperature, pain, stretch and touch
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which of the following is an example of procedural law? a. the specific…
D. The order in which the steps of a trial take place
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amelie wants to make her home as safe as possible for her family. which…
Test to see whether a carbon monoxide detector works.
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1. the nucleus of an atom consists of 8 protons and 6 neutrons. the tot…
1. C. 8 2. A. atomic number 3. C. \(_{64}^{158}X\) and \(_{64}^{159}X\) 4. A. \(1^{+}\) 5. D. fall back to lower energy levels 6. D. fewer electrons 7. B. It has a charge of \(+13…
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the periodic table has a different number of electrons and orbitals tha…
[Xe]6s^1
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why is choking considered an emergency situation? it may block the flow…
It may block the flow of air in the body.
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part b br express your answer in condensed form in order of increasing …
\([Ar]4s^{\wedge}23d^{\wedge}104p^{\wedge}5\)
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20 true or false 1 point this shows the law of conservation of mass whe…
False
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question 16 (1 point) find the percent concentration (m/v) when 14.2 g …
A. $3.16\%$
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help 6 of 10 review | constants | periodic table part a te express your…
[Kr]5s^24d^105p^4
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question 21 (1 point) the number of molecules contained in 22.4 l of an…
96 400
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draw a lewis structure for so₂ in which all atoms obey the octet rule. …
1. Lewis structure with octet rule (showing formal charges): - \(\overset{+1}{S}=\overset{0}{O}-\overset{-1}{O}\) (with appropriate lone pairs on \(O\) atoms). 2. Lewis structure …
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raising the temperature of 25 l of helium in a constant pressure contai…
Changes the volume to $473/373\times25\ L$ (the fourth option).
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question 18 (1 point) what is the ph of a 0.0001 m aqueous solution of …
4
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question 17 (1 point) if it takes 19 ml of h₂so₄(aq) to neutralize 50.0…
0.11 mol/L
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question 15 (1 point) quantities of water and 8.00 mol/l potassium nitr…
525 mL of 8.00 mol/L potassium nitrate and 175 mL of water.
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question 14 (1 point) a solution contains 0.90 g of sodium chloride dis…
0.15 mol/L
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question 13 (1 point) if equal masses of hydrogen and oxygen are combin…
Excess hydrogen will remain
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12 k + mgbr₂ → kbr + mg 10g 2g 6g? according to the law of conservation…
\(6\)
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what is the minimum number of moles of hno₃ needed to produce 8 moles o…
B. 16
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question 11 (1 point) if 24 g of c is consumed in 2c + o₂ → 2co, the ma…
C. \( 56\space g\)
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15 multiple choice 1 point which statement correctly describes the diff…
A physical change changes the substance's form without making a new substance; a chemical change produces one or more new substances.
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question 10 (1 point) what is the percentage, by mass, of oxygen in the…
15.2%
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put the steps of petroleum formation in their order of occurrence. firs…
1. Tiny marine organisms like algae and plankton died and sank to the ocean floor. 2. The remains of tiny marine organisms slowly decomposed into organic matter. 3. Organic matter…
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question 9 (1 point) 4 moles of co₂ has mass of: 12 g 44 g 112 g 176 g
176 g
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question 8 (1 point) the gram molecular mass (in g/mol) of h₂so₄ is 98 …
\(98\space g/mol\) (the first option)
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question 7 (1 point) saving... 1. the reaction: mgcl₂(aq) + 2 naoh(aq) …
double displacement
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look at the following illustration of an early american settler. it wou…
the color scheme used
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the coefficient of fe^{3+} in the balanced version of al + fe^{3+} → al…
\(3\)
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question 3 (1 point) the coefficient of o₂ in the balanced version of c…
B. 2
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sarah left a metal spoon in a pot of tomato sauce while it simmered for…
Brown - orange spots formed on the spoon's surface (color change).
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electronegativity values: k: 0.8 h: 2.1 br: 2.8 cl: 3.0 o: 3.5 f: 4.0 k…
K - Cl
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question 3 (1 point) if ion x has a charge 2+ and ion y has charge 3-, …
\(X_{3}Y_{2}\)
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question 2 (1 point) 1. which of the following is not the correct name …
I and IV
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question 1 (1 point) the nitrate ion is: no- no2- no3- nh4+
$NO_3^-$
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calculate the equilibrium constant k for the reaction: h₂(g) + i₂(g) ⇌ …
A. 48.2
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an equilibrium constant with a value of 8.0 × 10^6 indicates that at eq…
the products are favored
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what is the expression for the equilibrium constant for the reaction: 2…
\(K=\frac{[CO_2]^4[H_2O]^6}{[C_2H_6]^2[O_2]^7}\) (the second option)
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in a water solution, how do acids differ from bases? acids turn litmus …
Acids form hydrogen ions(H⁺), while bases form hydroxide ions (OH⁻)
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consider the following reaction. hcl(g) + nh₃(g) ⇌ nh₄cl(g) part 1 of 2…
Part 1 of 2: \(K=\frac{[NH_4Cl]}{[HCl][NH_3]}\) Part 2 of 2: \(K = 5.9\)
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acids are found on the ph scale between which numbers?
B. 0 - 7
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questions: 1. balance this reaction: ______ agno₃ + ______ nacl → _____…
1. \(1AgNO_3 + 1NaCl \to 1NaNO_3 + 1AgCl\) 2. Double - displacement reaction
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2. what is the reading in milliliters for each graduated cylinder?
11 ml, 16 ml, 75 ml, 40 ml, 65 ml, 13 ml, 16 ml, 85 ml, 75 ml, 55 ml, 98 ml, 75 ml, 7 ml, 65 ml, 90 ml
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question 8 2.5 pts according to jean piaget, in what stage do children …
Question 8: formal operational Question 9: accommodation
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hbr is an example of a(n) base acid neutral
B. Acid
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question 6 2.5 pts one - year - old ainsley learned the schema for truc…
- First question: assimilation - Second question: schemata
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write the expression for the equilibrium constant for the following equ…
\(K=\frac{[PCl_5]}{[PCl_3][Cl_2]}\)
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consider the reaction of ozone (o₃) with nitrogen monoxide (no), which …
- **Part 1 of 2**: Reaction rate decreases. - **Part 2 of 2**: Reaction rate increases.
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questions: 1. balance this reaction: ______ (nh₄)₂co₃ → ______nh₃ + ___…
1. \(1\ (NH_4)_2CO_3 ightarrow2\ NH_3 + 1\ CO_2+1\ H_2O\) 2. Decomposition reaction
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questions: 1. balance this reaction: ______ mg + ______ o₂ → ______ mgo…
1. \(2Mg + 1O_2 \to 2MgO\) 2. Combination reaction
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24. ___h₂s + ___cl₂ → ___s₈ + ___hcl 25. ___fe + ___h₂o → ___fe₃o₄ + __…
24. \(8\text{H}_2\text{S}+8\text{Cl}_2=\text{S}_8 + 16\text{HCl}\) 25. \(3\text{Fe}+4\text{H}_2\text{O}=\text{Fe}_3\text{O}_4 + 4\text{H}_2\) 26. \( \text{N}_2+3\text{H}_2 = 2\tex…
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questions: 1. balance this reaction: ______ ch₄ + ______ o₂ → ______ co…
1. \(1CH_4 + 2O_2 ightarrow1CO_2+2H_2O\) 2. Combustion reaction
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when atoms are combined in a compound, is the compound more stable or l…
The compound is more stable than the separate atoms. Atoms combine to form compounds to achieve a more stable electron configuration (e.g., noble - gas - like) and lower potential…
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which factor can decrease the rate of a chemical reaction? low activati…
low temperature
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the sweet slice pie shop sells organic pies with locally - sourced ingr…
\(\frac{2}{3}\)
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16. ___sio₂ + ___hf → ___sif₄ + ___h₂o 17. ___kclo₃ → ___kcl + ___o₂ 18…
16. \(1SiO_{2}+4HF = 1SiF_{4}+2H_{2}O\) 17. \(2KClO_{3}=2KCl + 3O_{2}\) 18. \(4KClO_{3}=3KClO_{4}+KCl\) 19. \(1P_{4}O_{10}+6H_{2}O = 4H_{3}PO_{4}\) 20. \(4Sb + 3O_{2}=1Sb_{4}O_{6}…
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what is a compound? write your answer in one complete sentence. 1000 ch…
A compound is a substance formed when two or more elements are chemically bonded together.
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what is the difference between a polar and nonpolar molecule? explain y…
A polar molecule has an uneven electron - density distribution (partial charges), while a nonpolar molecule has an even distribution (no significant partial charges). This impacts…
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8. fe + o₂ ---> fe₃o₄ 9. c₇h₆o₂ + o₂ ---> co₂ + h₂o 10. fes₂ + o₂ ---> …
8. \(3Fe + 2O_2=Fe_3O_4\) 9. \(2C_7H_6O_2 + 15O_2=14CO_2 + 6H_2O\) 10. \(4FeS_2+11O_2 = 2Fe_2O_3+8SO_2\) 11. \(Fe_2O_3+3H_2=2Fe + 3H_2O\) 12. \(2K+Br_2 = 2KBr\) 13. \(2C_2H_2+5O_2…
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question 1 - 22 the atom was not discovered all at once. rather, a seri…
The atomic theory is highly supported by scientific evidence and experimentation.
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which substance is a compound? salt phosphorus sulfur oxygen
salt
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lodine (i) would have chemical properties most like which of these labe…
Chlorine (Cl)
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question 1 - 20 elements on the periodic table are arranged into vertic…
Elements in a group have similar properties.
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question 1 - 19 atoms are comprised of subatomic particles. which of th…
C. Electrons
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question 1 - 18 which of the following best describes the composition o…
A nucleus of positive and neutral particles surrounded by negative particles.
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question 1-17 a student was assigned to take water samples from a lake …
Slightly acidic
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1. n₂ + 3h₂ → 2nh₃ how many grams of nh₃ can be produced from the react…
\(34\space g\) ### Problem 2
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what do these data indicate about gastric juice? it is very acidic. it …
It is very acidic.
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sugar (solute) water (solvent) sugar + water (mixture) which of the fol…
The mass of the sugar and water is the same as the mass of the sugar solution.
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question 1 - 11 as mia mixed two substances in a test tube, she noticed…
The two substances formed a new substance.
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what is an ion? explain in 1 - 2 sentences 1000 characters remaining
An ion is an atom or molecule that has gained or lost one or more electrons, resulting in a net electric charge.
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11. how much heat must be absorbed by a 15.0 g sample of water to raise…
$1882.8J$
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10. which sample is most likely to undergo the largest change in temper…
B. 10 g iron
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9. a cylinder with a moving piston expands from an initial volume of 0.…
\(1.67\ L\)
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8. when 2.00 g of liquid hexane (c₆h₁₄, mm = 86.18) undergoes combustio…
\(-1760\space kJ/mol\)
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7. what is the specific heat capacity of mercury if it requires 167.1 j…
$1.39\ J/(g\cdot^{\circ}C)$ (rounded to three significant figures)
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extra problems: 6. how much heat is required to raise the temperature o…
$233J$
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extra problems: 6. how much heat is required to raise the temperature o…
\(233\space J\)
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individual actions: - reduce - properly dispose of household chemicals …
- Individual Actions: - Reduce **fertilizer** and pesticide use on lawns - Pick up **pet** waste - Community Solutions: - Support green **infrastructure** projects - My Action Pla…
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caring for the land identify the problem and the solution and the main …
- Problem: Chemical pesticides and fertilizers harm non - target organisms, soil quality, and water. - Cause: Shift from natural nutrient replacement (e.g., animal manure) to inor…
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layers of soil identify the correct layers of soil. then label the pict…
From top to bottom: Organic (Humus), Topsoil, Subsoil, Parent Material, Bedrock.
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buyer beware! (1) grocery shoppers coast their carts through aisles of …
A. Companies offer "natural" products because they make and sell them cheaper than organic products.
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the properties of adhesion and cohesion of water are due to its heat ca…
1. polaridad 2. heat capacity 3. density 4. polarity
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select the correct answer. in this equation, what should be the coeffic…
A. the coefficient of iodine is 2, oxygen is 9, and the product is 2 (This option is wrong. The correct balanced equation is \(4I_2 + 9O_2=2I_4O_9\), so there is no correct option…
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select the correct answer. methane burns in oxygen to produce carbon di…
A. \(CH_4 + O_2 ightarrow CO_2+H_2O\)
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millions of years ago, maryland was covered by a shallow sea. when the …
- Rock Abrasion: \(\square\) Chemical, \(\blacksquare\) Mechanical - Freeze/Thaw: \(\square\) Chemical, \(\blacksquare\) Mechanical - Rusting: \(\blacksquare\) Chemical, \(\square…
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multiple choice 1 point why do scientists use electron dot diagrams? to…
To show how atoms might join
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multiple choice 1 point what do the dots in an electron dot diagram rep…
outer electrons
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step 1 of the phosphorus cycle is weathering. weathering can be describ…
The breakdown of rock and geologic structures due to rain and wind.
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3 as cookies bake, several chemical reactions occur. most of these reac…
B. They absorb more energy than they release
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2 classify the statements according to the part of a chemical reaction …
- Reactants: Chemical bonds break, Energy is absorbed. - Products: Chemical bonds form, Energy is released.
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how many moles of al₂s₃ are equivalent to 605 g al₂s₃? molar mass al₂s₃…
$4.03\ mol$
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what is the mass of 2.75 moles k₂s? molar mass k₂s = 110.27 g/mol
\(303.24\space g\) (rounded to four significant figures)
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what is the mass of 9.25 moles ba(oh)2? molar mass ba(oh)2 = 171.35 g/m…
\(1585.99\space g\) (rounded to two decimal places)
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how many moles are in 500. g mgbr₂? molar mass mgbr₂ = 184.11 g/mol
$2.72\ mol$ (rounded to three significant figures)
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how many moles of pbs are equivalent to 458 g pbs? molar mass pbs = 239…
$1.91$
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what is the mass of 10.0 mol ch₂o₂? 10.0 mol ch₂o₂ 46.0 g ch₂o₂ 1 mol c…
\(460\space g\)
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what is the mass of 10.0 mol ch₂o₂? lets begin by setting up our expres…
\(46.0\ g\ CH_2O_2\)
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what is the molar mass of ch2o2? 46.03 g/mol 29.0 g/mol 58.0 g/mol
46.03 g/mol