Química
Reacciones químicas, estequiometría, estructuras moleculares y propiedades.
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interpreting specific heat values | substance | ( c_p ) (j/g·°c) | |---…
Fe: 4 Al: 5 Cu: 3 Sn: 2 Pb: 1
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give the ion symbol for the ion that has 16 protons and 18 electrons.
\(\text{S}^{2-}\)
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question 7 for the combustion of ethylene, why does entropy decrease? b…
A. Because the products are more ordered than the reactants.
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give the ion symbol for the ion that has 16 protons and 18 electrons.
\(\ce{S^{2-}}\)
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question 6 in the context of entropy, what does a negative δs indicate …
The reaction leads to a decrease in disorder.
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check all of the following statements that are true about the ion whose…
To solve this, we analyze each statement about the \( \ce{F^-} \) ion: ### Step 1: Protons in Fluorine Fluorine (F) has an atomic number of 9, so a fluorine atom (and its ion \( \…
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question 5 which of the following reactions will have positive change i…
The reaction with a positive change in entropy is $\boldsymbol{CaCO_3 (s) ightarrow CaO (s) + CO_2 (g)}$ (the first option).
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hmis safety module quiz sc/nats 1830 a - mysteries of everyday m questi…
c. All of the above
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if a reaction has more moles of gas on the products side compared to th…
A. increases
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how many electrons would be found in the ion whose symbol is given belo…
10
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question 3 how can the entropy change for a reaction be predicted witho…
A. By comparing the moles of gaseous reactants and products.
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true or false: the standard molar entropy of a pure element in its stan…
False
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question 1 which property of entropy allows it to be calculated from re…
B. Its status as a state function.
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6b. explain how the kinetic energy of the molecules in the instant hot …
When heat transfers from the instant hot pack to the cold bench (as in 6a, assuming heat flows from hot to cold), the molecules in the instant hot pack lose thermal energy. Since …
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complete the ion symbol for the atom below.
\( \ce{^{14}_{7}N^{-}} \) (or \( \ce{^{15}_{7}N^{-}} \) if neutrons are 8; but likely \( \ce{^{14}_{7}N^{-}} \) as nitrogen-14 is common)
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based on the bond energies for the reaction below, what is the enthalpy…
\boxed{-1222}
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check all of the following statements that are true about the ion whose…
- The ion has 20 protons. - The ion has lost two electrons.
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using the equations $ce{h2(g) + f2(g) -> 2 hf(g)}$ \t $delta h^circ = -…
299.7
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give the ion symbol for the ion that has 15 protons and 18 electrons.
\( \text{P}^{3-} \)
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how many electrons would be found in the ion whose symbol is given belo…
The \( \text{I}^- \) ion has \(\boldsymbol{54}\) electrons.
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this quiz: 49 point(s) pos... this question: 7 point(s)... 4 of 7... pl…
Hand line ### Question 2
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determine whether each of the properties described applies to volumetri…
volumetric ### For "Capable of measuring a range of volumes of liquid":
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points possible: 1.00 identify effective techniques for accurate pipet …
A. Measure liquid by aligning the meniscus with the volume line. B. Do not let liquid enter the pipet bulb or pump.
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the table shows the properties of three classifications of elements. | …
B. (A) Non - metals, (B) Metalloids, and (C) Metals
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identify effective techniques for accurate pipet use. select all that a…
A. Measure liquid by aligning the meniscus with the volume line, B. Do not let liquid enter the pipet bulb or pump
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true or false: the coefficient in a chemical formula only applies to th…
False
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in order to use a pipet, place a bulb or pump at the top of the pipet. …
inside
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how do you find the number of atoms of an element when it has both a su…
The correct option is: "Multiply everything by the coefficient then add up the totals"
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a pipet, place a bulb or pump at the top of the pipet. use this object …
For the middle "Choose..." (the one with options meniscus and top), the answer is meniscus.
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points possible: 1.00 determine whether each of the errors listed affec…
contamination ### 2. The liquid level in a pipet is read from the top of the curve rather than the meniscus.
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the table shows the physical properties of four elements. | element | l…
D. Polonium
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a ________ pipette is designed to deliver a single volume precisely. se…
C. volumetric
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what type of substance can be placed directly on the pan of an electron…
C. solid objects only (assuming the third option is labeled C; if the original options had labels like A, B, C, D with the third being "solid objects only", then the answer is the…
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all of the following elements are metals except – a. lead (pb) b. iron …
D. Silicon (Si)
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which of the following elements has the physical properties of malleabi…
A. Copper (Cu)
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points possible: 1.00 what should you always do before placing an objec…
A. Make sure the reading is zero.
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question 11 of 18 points possible: 1.00 when using a properly stabilize…
C. Measure the mass of the sample at room temperature, D. Close the side shields on the balance during reading.
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points possible: 1.00 suppose you are measuring the mass of a solid sam…
\( 4.750 \)
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when using the tare function on a balance, start by choose... then, cho…
First "Choose...": place the glassware on the balance Second "Choose...": press the Tare/Zero button Third "Choose...": add your sample to the glassware
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the molecules in a solid lump of sugar do not move. true or false
False
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identify which balance was used to make each mass reading. 1.230 g choo…
To solve this, we analyze the number of decimal places (precision) of each mass reading and match it to the balance's tolerance: ### For \( 1.230 \, \text{g} \): - It has 3 decima…
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what should you do if you are using a balance that has persistent fluct…
D. Contact your TA or instructor to adjust the balance.
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montreal protocol and stockholm convention were for________and________,…
D. phasing out chlorofluro carbons (CFC); reducing the use of dirty persistent organic pollutants (POP)
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what are the best practices while sharing a lab balance with other stud…
A. Leave a note when you have tared a balance for your glassware, B. Brush off any chemical dust around the balance after each use, C. Alert your TA or instructor about any issues…
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16. how many significant figures are in the following measurements? a. …
1 ### Part b: \( 3.00\times10^{8} \, \text{m/s} \)
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what are the formal charges of both chlorines and iodine in icl₂⁻? sele…
D. 0, -1
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from ax₄e₀ geometry to ax₃e₁, what is the change in geometry? select on…
C. Tetrahedral to Trigonal Pyramidal
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question 3 of 18 points possible: 1.00 write the axe notation for h₂o. …
C. \( \text{AX}_2\text{E}_2 \)
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what is the electron geometry of the carbon in h₂co? select one: a. tri…
B. Trigonal Planar
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write the molecular geometry of tef₄. select one: a. trigonal bipyramid…
D. See Saw
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67. define the word part uvea-. ○ radiation ○ grape ○ smaller ○ lung 68…
B. grape ### Question 68
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nitric acid express your answer as a chemical formula. a chemical react…
$\ce{HNO_3}$
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hydrofluoric acid express your answer as a chemical formula. a chemical…
$HF$ ### Part B: Hydrobromic Acid
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lee la pregunta y elige la mejor respuesta. cuando el dióxido de carbon…
B. El hielo seco se sublima a temperatura ambiente y presión estándar. ### Question 24
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aluminum nitrate dihydrate express your answer as a chemical formula.
$\ce{Al(NO_{3})_{3}\cdot 2H_{2}O}$
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cuso₄·2h₂o spell out the full name of the compound. text box submit req…
copper(II) sulfate dihydrate ### Part D (Formula for aluminum nitrate dihydrate)
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fei₂·4h₂o spell out the full name of the compound. part b nickel(ii) ni…
iron(II) iodide tetrahydrate ### Part B
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calcium phosphate express your answer as a chemical formula. a chemical…
$Ca_3(PO_4)_2$
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iron(iii) hydroxide express your answer as a chemical formula.
$\boldsymbol{Fe(OH)_3}$
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a number of recent, high - profile foodborne illness outbreaks have inc…
C. Microbial contamination causes most foodborne illness incidents.
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certifies organic foods in the u.s. controls product labels regulates q…
To solve this, we match each regulatory task to the correct agency: ### USDA (United States Department of Agriculture) - Certifies organic foods in the U.S. (USDA oversees organic…
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read the text. now in our seventh growing season, the stafford communit…
to encourage readers to support the community garden program
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iron(iii) hydroxide express your answer as a chemical formula. input bo…
s: Iron(III) hydroxide: \( \text{Fe(OH)}_3 \) Calcium phosphate: \( \text{Ca}_3(\text{PO}_4)_2 \)
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iron(iii) chromate express your answer as a chemical formula. input box…
$\text{Fe}_2(\text{CrO}_4)_3$ ### Iron(III) Fluoride
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question 28 of 30 points possible: 1.00 to prevent accidental ingestion…
c. On the table just outside the laboratory entrance. d. Inside a backpack that is fully zipped closed.
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many bad things come with cars, however. for one thing, cars ______ gas…
A. require
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question 22 of 30 points possible: 1.00 changing gloves often will mini…
First, \boxed{peel off the first glove}, and then, peel off the first glove (note: possible typo in sentence structure), then insert \boxed{a bare finger} between the interior edg…
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history of the atom coloring page for each question, there is one corre…
Thomson (RED) ### Question 2
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108) cerebral ischemia results in a condition termed: ○ apoplexy ○ deme…
A. apoplexy ### Question 109
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question 22 of 30 points possible: 1.00 changing gloves often will mini…
The proper steps for glove removal (in order) are: First, peel off the first glove (inside - out); then, hold the first glove in the gloved hand; then insert bare fingers between …
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29) herpes in greek means: ○ to flow ○ to creep ○ to scab ○ to scar 30)…
B. to creep (assuming the options are labeled A: to flow, B: to creep, C: to scab, D: to scar) ### Question 30
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copper(ii) chloride express your answer as a chemical formula. input bo…
$CuCl_2$ ### Part B: copper(I) iodate
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ordering 1 point predict the order of decreasing radius for germanium, …
1. cesium 2. potassium 3. germanium 4. bromine
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multiple choice question a routine ______ is for the examination of uri…
C. urinalysis
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identifying parts of a chemical equation identify each part of this che…
A: reactants B: plus sign (or "and" sign, to separate reactants) E: products (Note: For B, it can also be described as the "plus" symbol used to separate reactant formulas; the ke…
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note: to answer some of the questions, it may help to reference a perio…
A. $2-$
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if an atom of gold (au) contains 79 protons and 118 neutrons, what is i…
197 (corresponding to the option with 197)
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by taking this checkpoint, you will check your understanding of the con…
francium (Fr)
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by taking this checkpoint, you will check your understanding of the con…
A. atomic mass unit
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by taking this checkpoint, you will check your understanding of the con…
- Particles with opposite charges are attracted to each other. - Particles with the same charge repel each other.
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question 21 of 30 > points possible: 1.00 which is not a good source of…
C. Your lab partner
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by taking this checkpoint, you will check your understanding of the con…
A. neutron
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by taking this checkpoint, you will check your understanding of the con…
D. It showed that atoms are tiny, indivisible spheres with no charge and no substructure. (Here we assume the options are labeled A, B, C, D in order. If the original options had …
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if you drop or break glassware in lab, first choose... then, choose... …
(Filling the Blanks): - First: Notify your instructor (or "Put on protective gloves") - Then: Use a brush and dustpan to collect the glass - Finally: Broken glass disposal contain…
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by taking this checkpoint, you will check your understanding of the con…
The correct option is: Thomson’s model depicted atoms as tiny positive spheres with negative charges while Dalton’s model showed atoms as spheres with no charge.
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question 19 of 30 > points possible: 1.00 what information is necessary…
B. Hazard warnings, C. Handling, storage, and reactivity information, D. Personal protection and first aid recommendations, E. Identification and description of substance
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which diagram is the best representation of the electron energy orbital…
The correct diagram (assuming the standard ground - state electron configuration for carbon) is the one that has \(1s^2\), \(2s^2\), and \(2p^2\) with electrons in \(1s\), \(2s\),…
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question 18 of 30 points possible: 1.00 review the safety data sheet (s…
To solve this, we refer to the Safety Data Sheet (SDS) for hydrogen peroxide: ### In case of skin contact: Wash the affected area thoroughly with plenty of soap and water. Remove …
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when should lab participants look at the safety data sheet (sds) of a s…
C. Before using the substance
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multiple choice 1 point consider the electron energy orbital diagram fo…
A. 1s orbital
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determine which economic principle is illustrated by each scenario. a. …
equilibrium ### Part b
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read the safety data sheet (sds) of hydrogen peroxide to identify the t…
B. Tightly fitting safety goggles
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multiple choice 1 point consider the electron energy orbital diagram fo…
A. 1s orbital
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identify the section in which each type of information can be found on …
s: - chemical name and formula: Identification (Section 1) - recommended personal protective equipment (PPE): Exposure Controls/Personal Protection (Section 8) - recommendations i…
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multiple choice 1 point 2 consider the electron energy orbital diagram …
D. 3s orbital (assuming the options are labeled as A. 1s orbital, B. 2s orbital, C. 2p orbitals, D. 3s orbital based on the order in the image)
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question 14 of 30 points possible: 1.00 read the safety data sheet (cli…
In a tightly closed container in a dry and well - ventilated place
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how should students prepare to use chemicals in the lab? select one or …
B. Become familiar with the chemicals to be used, including exposure or spill hazards. C. Locate the spill kits and understand how they are used.
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which diagram is the best representation of the electron energy orbital…
C (the diagram labeled C)
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question 11 of 30 points possible: 1.00 tries remaining: 2 most laborat…
The correct option is: Neutralize the spill before cleaning it up.
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in lab, you may need to evaluate the odor or smell of a chemical. what …
C. Use your hand to gently waft the smell toward you.