Chemie
Chemische Reaktionen, Stöchiometrie, Molekülstrukturen und Elementeigenschaften.
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¿cómo se llama el cambio de fase de líquido a gas? por ejemplo: agua lí…
# Explicación breve: - **Primera pregunta**: La fusión es el cambio de sólido a líquido, la congelación es el cambio de líquido a sólido, la condensación es el cambio de gas a líq…
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en este estado de la materia las partículas están muy separadas y tiene…
Primera pregunta: Gas Segunda pregunta: Congelación
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este estado de la materia se expande para llenar el volumen de cualquie…
- Primer pregunta: C. Gas - Segunda pregunta: A. Sólido
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17. a balanced chemical equation is shown below. c + o₂ → co₂ how would…
A.
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activity 2 another student places a bowl on a laboratory scale and puts…
C.
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13. karsandra and alex conducted an experiment where they heated water …
B. The law of conservation of matter was not broken because the water was heated in an open beaker, letting gases escape.
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10. because the balloon is placed on top of the flask, the substances i…
A. \(64.2\space g\) ### Question 12
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directions: select the correct answer. carbon - 14 has a half - life of…
2
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10. what does the pink part of the acid represent: what does the yellow…
10. - Pink part: Carboxyl group. - Yellow part: Hydrocarbon chain. - Blue part: Methyl group. 11. Saturated. 12. Unsaturated.
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3. explain how friction affects mechanical energy. 4. how much energy d…
\( 25W \)
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question: as a web designer, youre tasked with making sure that all pro…
Ensure text is legible and structured.
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complete the word equation then underneath show the skeleton chemical e…
Sulphuric acid + lithium hydroxide → lithium sulphate + water The skeleton chemical equation: \(H_{2}SO_{4}+LiOH ightarrow Li_{2}SO_{4}+H_{2}O\)
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1. using the mole weight, calculate the number of moles in each of the …
a. Approximately \(0.121\ mol\) b. Approximately \(3.85\ mol\) c. Approximately \(0.305\ mol\) d. Approximately \(2.27\ mol\) e. \(1.5\ mol\)
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1. in step 1, what was the evidence that a chemical reaction occurred? …
- \(2Al+Fe_2O_3 ightarrow 2Fe + Al_2O_3\), Reaction type: Single - replacement reaction - \(PbCl_2+Li_2SO_4 ightarrow PbSO_4 + 2LiCl\), Reaction type: Double - replacement reactio…
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question 27 1 pts what are the spectator ions in the reaction between k…
\(K^{+}\) and \(NO_{3}^{-}\) (corresponding to the option \(K^{+}\) and \(NO_{3}^{-}\))
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2 agno₃(aq) + k₂so₄(aq) → 2 kno₃(aq) + ag₂so₄(s) the net ionic reaction…
For the first question (net - ionic reaction), the answer is \(2Ag^{+}+SO_{4}^{2 -}\to Ag_{2}SO_{4}\). For the second question (spectator ions), the answer is potassium ion and ni…
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question 23 1 pts the following reaction can be classified as what type…
### Question 23 metathesis reaction, acid - base neutralization ### Question 24 \(H_2SO_4(aq)+Ca(OH)_2(aq)\to CaSO_4(aq) + 2H_2O(l)\)
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question 21 1 pts the balanced equation for the reaction occurring when…
\(3Ca(NO_3)_2(aq)+2Na_3PO_4(aq)\to Ca_3(PO_4)_2(s)+6NaNO_3(aq)\) (the fourth option) ### Question 22
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question 20 1 pts when the reaction shown is balanced, there are ______…
C. \(8;14\)
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question 19 1 pts in the correctly balanced reaction the coefficient fo…
C. 6
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question 17 1 pts when the following reaction is balanced the coefficie…
For the first reaction (Question 17), the coefficient in front of \(CO_{2}\) is 5. For the second reaction (Question 18), the coefficient in front of \(O_{2}\) is 25.
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question 15 1 pts the reaction between strontium hydroxide and chloric …
a molecular compound and an ionic compound ### Question 16
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question 13 1 pts which combination will produce a precipitate? naoh (a…
Question 13: \(KOH(aq)\) and \(Mg(NO_3)_2(aq)\) Question 14: \(H^{+}(aq)+OH^{-}(aq) ightarrow H_2O(l)\)
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the combustion of propane (c3hg) in the presence of excess oxygen yield…
1.5
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a compound that is composed of carbon, hydrogen, and oxygen contains 70…
\(C_{8}H_{8}O_{2}\)
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a compound contains 40.0% c, 6.71% h, and 53.29% o by mass. the molecul…
\(C_{2}H_{4}O_{2}\)
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there are ________ hydrogen atoms in 25 molecules of c4h4s2. 1.5 × 10^2…
100
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question 6 1 pts a nitrogen oxide is 63.65% by mass nitrogen. the molec…
\(N_2O\) ### Question 7
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question 4 1 pts calculate the percentage by mass of nitrogen in ptcl2(…
Question 4: 9.34 Question 5: 0.169
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question 2 the formula of nitrobenzene is c6h5no2. the molecular weight…
Question 2: 123.11 g/mol (the third option). Question 3: 74.87 (the fifth option).
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the reaction of 25 ml of n₂ gas with 75 ml of h₂ gas to form ammonia vi…
50
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question 24 1 pts redox reactions involving metals often give rise to t…
Question 24: metal cation Question 25: (Assuming the option for hydrogen gas is missing. If we consider the given options, there is an error. But if we go by the principle of redo…
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question 22 1 pts an oxidation - reduction reaction redox reaction invo…
Question 22: B. electrons Question 23: A. single - displacement
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question 20 1 pts the products of an acid - base reaction are often a_.…
Question 20: B. salt and water Question 21: D. oxidation - reduction reactions
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question 16 1 pts _____ only partially dissociate, leaving a large majo…
Weak acids
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question 14 1 pts an acid may be defined as a substance that will disso…
Question 14: hydronium ions Question 15: Strong acids
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question 12 1 pts predict the precipitate that will be formed in the fo…
AgF(s) # Question 13
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consider the following reaction: 2ki(aq) + pb(no₃)₂(aq) → pbi₂(s) + 2kn…
\(\text{Pb}^{2 +}(aq)+2\text{I}^{-}(aq)\to\text{PbI}_2(s)\) (the fourth option).
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it is also possible to predict which compounds are likely to be insolub…
compounds containing hydroxide, Compounds containing phosphates, Compounds containing carbonates.
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question 9 1 pts it is possible to predict the solubility of a given io…
- Compounds containing nitrate ions - Compounds containing group I cations - Compounds containing acetate ions
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answer the following questions. 1) select all that apply. select three …
1. whether the restaurant is up to code, whether the restaurant has healthy food options, whether the restaurant has a health certificate 2. sparingly
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3) choose the best answer. why can salad bars and buffets be unsafe? th…
3) The food may be exposed to the air for a long time, letting bacteria reproduce. 4) You want food that makes you feel good.
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5. list 3 everyday examples of the cohesive and/or adhesive properties …
- Cohesion examples: Water droplets forming spheres, water beading on waxed car hood, capillary action in plants (due to cohesion aspect). - Adhesion examples: Water climbing glas…
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which of the following are physical changes that may have occurred in t…
The leaves changed color from green to red, orange, and yellow.
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clouds are formed when water from the surface of the earth heats up to …
Evaporation then condensation
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what are some physical properties of the metal in this necklace? it has…
All of these are correct.
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which of the following are chemical changes that may have occurred in t…
The leaves changed color from green to red, orange, and yellow.
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which of the following is an intensive property? melting point all of t…
B. ALL of these
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what happens to the temperature of a substance as it changes phases? it…
It remains constant.
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which of the following is an extensive property? freezing point all of …
Mass
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matter is defined as anything that... has mass and volume. has mass. ha…
has mass and volume.
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what happens to the particles in a liquid when you lower the temperatur…
The particles slow down.
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which of the following are physical changes that may have occurred in t…
The leaves changed color from green to red, orange, and yellow.
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what happens to the particles in a liquid when you raise the temperatur…
The particles move faster.
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clouds are formed when water from the surface of the earth heats up to …
Evaporation then condensation.
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which of the following is a homogeneous mixture? salt dissolved in wate…
Salt dissolved in water
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which of the following is a heterogeneous mixture? sugar water a sample…
Cereal with milk
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which of these descriptions is accurate? all of these are accurate. gas…
ALL of these are accurate.
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what is one reason that organic shapes are used in art? to convey a sen…
To convey a sense of naturalness and spontaneity
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what are some characteristics of organic shapes? adherence to geometric…
Asymmetrical forms and flowing lines
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what is an example of how organic shapes can be used as symbols in art?…
B. A leaf shape symbolizing growth and renewal
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what is an organic shape? a shape that is repeated in a pattern a shape…
A shape found in nature and not defined by mathematical principles.
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what is the best answer for explaining that a triangle is not an organi…
A triangle is not an organic shape because it is a geometric shape with defined angles and straight lines.
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89. we obtain uranium - 235 from u - 238 by fluorinating the uranium to…
The ratio of effusion rates \(\frac{r_{238}}{r_{235}}\approx0.9957\)
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calculate the root mean square velocity and kinetic energy of $f_{2}$, …
- Root - mean - square velocities: \(v_{rms,F_2}\approx442\space m/s\), \(v_{rms,Cl_2}\approx324\space m/s\), \(v_{rms,Br_2}\approx216\space m/s\) - Kinetic energies: \(E_{k,F_2}=…
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question 7 1 pts substance will when solution conditions are such that …
Question 7: C. precipitate Question 8: D. insoluble
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question 5 1 pts __________is defined as the maximum concentration that…
Question 5: Solubility Question 6: soluble
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a precipitation reaction is also sometimes referred to as a reaction. s…
- First question: C. double displacement - Second question: B. precipitation
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which of the following represent common types of chemical reactions? (p…
- First question: Precipitation, acid - base, oxidation - reduction. - Second question: solid.
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what is the molecular formula for a compound with an empirical formula …
\(C_{6}H_{6}\) ---
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question 23 1 pts for a compound whose empirical formula has been deter…
6
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which of the following equations properly describes the ratio of the mo…
First option: \(\frac{molecular\ or\ molar\ mass(amu\ or\frac{g}{mol})}{empirical\ formula\ mass(amu\ or\frac{g}{mol})}=n\ formula\ units/molecule\)
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molecular formulas are determined from the ratio of the compounds molec…
First question: empirical formula mass. Second question: empirical formula mass.
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1 pts empirical formulas are formulas representing the relative numbers…
- First question: smallest whole number ratios - Second question: empirical formula, molecular mass
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given the molar ratio of chlorine to oxygen in the sample, and the whol…
\(Cl_{2}O_{7}\)
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given the molar ratio of chlorine to oxygen in the sample, what number …
2
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given the same 12.50 g sample containing chlorine and oxygen, simplify …
Cl: \(1\space mol\space Cl\), O: \(3.5\space mol\space O\)
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a 12.50 g sample containing chlorine and oxygen is found to have the co…
Moles of \(Cl\): \(\frac{38.76}{35.45}\approx1.093\) mol Moles of \(O\): \(\frac{61.24}{16.00}=3.8275\) mol
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a 12.50 g sample of a compound containing chlorine and oxygen is analyz…
Cl: \(38.76\space g\), O: \(61.24\space g\)
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question 12 1 pts since the scale for percentages is _, it is convenien…
100%, 100 g
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1 pts match the steps to derive empirical formulas from experimentally …
Step 1: Derive number of moles of each element using the molar mass of the element; Step 2: Divide each molar amount by smallest of the molar amounts; Step 3: Multiply all coeffic…
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experimentally derived chemical formulas represent the relative numbers…
whole number
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what is the percent composition by mass for each element in lactose c₁₂…
$\%$C: $42.10\%$; $\%$H: $6.49\%$; $\%$O: $51.41\%$
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what is the total formula mass in amu for lactose, c₁₂h₂₂o₁₁? 154.25 am…
342.3 amu
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question 7 1 pts for a compound whose formula is known, the percent com…
formula mass, atomic masses
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question 5 1 pts percent composition is also useful for evaluating the_…
relative abundance ### Question 6
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question 4 1 pts a sample of a liquid with a mass of 8.657 grams was de…
C. \( C:60.26\%, H:11.11\%, O:28.62\%\)
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question 3 1 pts calculate the percent composition of hydrogen and carb…
25.2%, 74.8%
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the______is defined as the percentage by mass of each element present i…
- Question 1: percent composition - Question 2: \(\%\text{X}=\frac{\text{mass X}}{\text{mass compound}}\times100\%\) (the first option in Question 2)
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automobile air bags inflate following a serious impact. the impact trig…
\(22.8\space g\)
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which of the following is a double replacement reaction? 2ag + h₂s → ag…
\(2KI + Pb(NO_3)_2 ightarrow 2KNO_3+PbI_2\)
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multiple - choice question which is a single replacement reaction? 2c₅h…
\(Pb + FeSO_{4}=PbSO_{4}+Fe\) is a single - replacement reaction.
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true or false: the phosphorus cycle is one of the fastest biogeochemica…
FALSE
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which biogeochemical cycle is the only one that does not include the at…
Phosphorus
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select the correct answer. which statement best describes a solution? a…
C. a mixture having a uniform composition where the components can't be seen separately and all components are in the same state
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select the correct answer. which statement best compares the density am…
C. Solids have the highest density among the three, gases have the lowest, and liquids are slightly less dense than solids but much denser than gases.
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the carbon returns in the form of what compound? carbon dioxide sugar c…
carbon dioxide
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environmental protection agency occupational safety and health administ…
Dwayne's company → Occupational Safety and Health Administration Ryan's new car → Environmental Protection Agency Lisa's yogurt → Food and Drug Administration
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23. what element of art refers to a closed line that can be geometric o…
A. Shape
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analysis of part 1: paper chromatography 1. describe in detail what was…
1. Solvent moved up filter paper by capillary action, carrying leaf extract pigments at different rates based on solubility and paper affinity. 2. A substance that dissolves solut…