化学
化学反应、化学计量、分子结构与元素性质。
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step 1 – sketch the lewis structure from the molecular formula, drawing…
All entries in the table are verified as correct: 1. For $\ce{CH4}$: Lewis structure (109.5° bond angle), electron geometry = tetrahedral, molecular geometry = tetrahedral, nonpol…
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the rapid movement of gases molecules can be explained because gases ha…
D. small, little
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the molecules of a substance are moving rapidly in a container. the mol…
B. gas
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open-ended question what does the law of conservation of mass state?
The law of conservation of mass states that in a closed system, the total mass of substances before a chemical reaction (reactants) is equal to the total mass of substances after …
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a potassium iodide compound is represented by which formula? a k₂i b k₂…
C. \( KI \) (assuming option C is \( KI \); adjust based on exact option labels, but the correct formula for potassium iodide is \( KI \))
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isotopes of an element differ in the composition of the nucleus. the va…
B. neutrons, mass number
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most elements on the periodic table are a gases b metals c nonmetals d …
B. metals
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a positively charged ion will bond with a a negatively charged ion. b a…
A. a negatively charged ion.
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how many grams of o₂ are required to produce 358.5 grams of zno? 2zn+o₂…
70.4 g
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consider this row in the periodic table of elements. evaluate which ele…
A. lithium and beryllium
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based on the mole ratios of the substances in a chemical reaction shown…
D. \( 3A + 2B ightarrow C \) (Note: Assuming the last option is D as per the order, with the equation \( 3A + 2B ightarrow C \))
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write the formula for the following compounds: | compound | formula | |…
### Formula Writing: 1. Calcium chloride: $\text{CaCl}_2$ 2. Carbon trioxide: $\text{CO}_3$ 3. Magnesium oxide: $\text{MgO}$ 4. Dinitrogen pentoxide: $\text{N}_2\text{O}_5$ 5. Alu…
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the unbalanced chemical equation for the reaction of magnesium nitrate …
1:3
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check out the picture of the periodic table of elements. follow the arr…
C. The elements change from metals to nonmetals.
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the unbalanced chemical equation for the decomposition of aluminum oxid…
40 moles (corresponding to the option "40 moles")
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which statement accurately describes covalent bonds? a covalent bonds a…
B. Covalent bonds are typical of carbon compounds.
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using the periodic table, elaborate the difference between the number o…
D. The number of electrons are the same for all isotopes of an element - so both oxygen - 16 and oxygen - 18 contain 8 electrons.
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do these molecules make up the same substance? yes no
no
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and one oxygen atom. what is the chemical formula for the substance com…
$C_2H_4O$ (corresponding to the option with formula $C_2H_4O$)
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first, select the model of a molecule composed of two carbon atoms and …
The model labeled "ethane" (the first molecular model with two carbon atoms and six hydrogen atoms). ### Part 2: Select the chemical formula
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select all the ways in which two substances can be different two substa…
All three options (the ones stating "Two substances can be composed of the same chemical elements, but the substances can have crystal structures with atoms that are arranged diff…
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1) complete the statement. 2) these molecules make up 3) the same subst…
different substances
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____ are different forms of a single element. a atoms b elements c ions…
D. Isotopes
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the periodic table organizes elements according to increasing a atomic …
C. atomic number
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select the model of a molecule composed of one carbon atom, two hydroge…
The first model (labeled "formic acid") ### Part 2: Determining the chemical formula
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what is the chemical formula for aluminum nitride? a al₃ b aln₃ c al₃n₃…
D. AlN
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the rapid movement of gases molecules can be explained because gases ha…
D. small, little
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4) first, select the model of a molecule composed of two carbon atoms a…
Left model (labeled "ethylene" or "ethene") ### Part 2: Chemical formula for 10 ethylene molecules
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given the following mystery ions, \\(x^{3+}\\) \\(m^{2-}\\) \\(q^{2+}\\…
A. $Q_2M_2$
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an atom that has lost or gained electrons is known as an ion. which com…
C. \( \text{KBr} \)
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a group on the periodic table is best described as a ______. a column b…
A. column
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question 5 mechanical weathering process that occurs when water repeate…
A. frost wedging
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weathering pre and post learning quiz started: feb 5 at 7:47am quiz ins…
A. exfoliation
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question 1 20 pts process by which rocks and minerals undergo changes i…
A. chemical weathering
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why are biogeochemical cycles important? earth is a closed system. that…
First drop - down: stays the same (or remains constant) Second drop - down: recycle (or reuse, circulate)
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question 5 of 10 to measure how much stuff is in a specified volume of …
density
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when classifying matter, it is helpful to organize your information in …
1. element 2. compound 3. suspension 4. solution 5. colloid
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directions: match the terms in column ii with the definitions in column…
## Matching Section 1. f. suspension 2. h. homogeneous mixture 3. e. element 4. d. mixture 5. a. Tyndall effect 6. b. colloid 7. c. heterogeneous mixture 8. g. solution 9. i. comp…
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question 2 points 2 identify the grammatically correct sentence. the un…
B. The university offers many majors in engineering, such as chemical, industrial, and electrical engineering.
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temperature and solubility background knowledge it is easier to dissolv…
Yes, there is a relationship. As temperature increases (from \(20^{\circ}\text{C}\) to \(60^{\circ}\text{C}\)), the solubility of table salt (amount dissolved per jug) increases (…
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6. fill in the missing information in the table below. note: all soluti…
To solve this, we need the solubility values of each solute at the given temperatures (from solubility tables): ### 1. Solution: A solution that contains 70 g of $\ce{NaNO3}$ at $…
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6. fill in the missing information in the table below. note: all soluti…
To solve this, we need the solubility data (in g per 100 mL water) for each solute at the given temperatures. Let's recall typical solubility values (from solubility curves): ### …
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using the above solubility curve, answer the given questions. 1. which …
\(KClO_3\) (or other correct salt based on the curve, but \(KClO_3\) is a common answer here) ### Question 2
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draw simple graphs that show the relationship between temperature and s…
### 1. Temperature vs. Solubility (Liquid and Solid Solutes) #### Explanation: For most solid and liquid solutes, solubility generally increases with an increase in temperature. W…
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barometric pressure (mmhg) 770.0 observations bubble formation. volume …
To find the ideal gas constant \( R \), we use the ideal gas law \( PV = nRT \), where: - \( P = 1.013 \, \text{atm} \) (pressure of \( \text{H}_2 \)), - \( V = 0.0190 \, \text{L}…
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barometric pressure (mmhg) observations bubble formation. volume of hyd…
To solve for the moles of hydrogen gas produced, we use the ideal gas law, \( PV = nRT \), where: - \( P \) = pressure of hydrogen gas (atm), - \( V \) = volume of hydrogen gas (L…
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question 10 of 14 each image depicts what happens when different types …
- Strong electrolyte: The middle image (only separate blue spheres and gray charged spheres, no intact paired molecules) - Weak electrolyte: The bottom image (a mix of intact pair…
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question 4 of 14 write the balanced chemical equation for the reaction …
$\boldsymbol{2\text{NO} + \text{O}_2 = 2\text{NO}_2}$
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11) choose the correct answer. global warming is an example of ____. ra…
C. climate change ### Question 12
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3) choose the correct answer. ____ occurs when pollutants from the smok…
C. Acid rain ### Question 4
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complete the following table. draw arrows between the lewis dot structu…
| Category | Potassium | Fluorine | Selenium | Calcium | |----------|-----------|----------|----------|---------| | Group A# | IA | VIIA | VIA | IIA | | # Valence Electrons | 1 | …
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of weathered bedrock. p. 165 6. ______________you can use the ph scale …
B. B horizon ### Question 8
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question 8 based on the article, which of these is true? a. highly reac…
D. Highly reactive metals are on the left side of the periodic table.
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which of the following statements most accurately defines clarissa dall…
She is a wealthy woman who can afford a nice house, a servant, and catering. ### Question 6 (Solemnity - Likely Situation)
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6. what are the products of the chemical equation to make a balanced ch…
c. $\ce{2 HNO2 + 1 Na2SO4}$
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4. what are the products of the chemical equation to make a balanced ch…
b. $2\text{H}_2\text{O}_2$
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one student claims that the meaning of this balanced equation is \2 gra…
Disagree. Coefficients represent mole/particle ratios, not mass ratios. The correct mass relationship is 4 g $\text{H}_2$ reacts with 32 g $\text{O}_2$ to form 36 g $\text{H}_2\te…
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2. what would increase the temperature during a chemical reaction? a. t…
2. c. The collision rate of the reactant particles increased. 3. b. The molecules move faster as a gas than they do as a liquid.
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1254 grams of sodium chloride is combined with 2158 grams of barium pho…
Approximately $\boldsymbol{1173\space g}$ (or more precise value around 1172 - 1173 g) ### 2. Limiting Reactant
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22. a puddle left in the sunlight disappears after a couple hours 23. i…
Evaporation (Liquid → Gas) ### 23. Icicles forming on a tree at night
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using the formula provided, convert kelvin to celsius #°k - 273.15 step…
1. Phase Change: Melting 2. Molecular Movement: - Before: Molecules are moving (vibrating) in place (solid state). - After: Molecules are moving around each other (liquid state). …
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depression and anxiety: test : _______________________________ score: _…
s (Part 1 - Classifications, Part 2 - Blanks) 1. Both 2. Both 3. Both 4. Both (or A) 5. Both 6. Both 7. Both 8. Both (or A) 9. depression 10. medication 11. anxiety 12. goodbye 13…
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using the formula provided, convert kelvin to celsius #°k - 273.15 \t s…
\( 0^\circ\text{C} \) ### Question 18: Convert 773.15 K to Celsius
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parts of a pot number correct: ______/4 mouth. 1. this is the part of t…
### Glaze Matching: 1. Matte Glaze- A type of glaze which creates a flat/dull coating on a clay surface. 2. Underglaze- Glass-forming chemicals, usually with coloring compounds ad…
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selenium-50 selenium-55 # of protons # of neutrons # of electrons sodiu…
### Sodium Table | | Sodium-12 | Sodium-20 | |----------------|-----------|-----------| | # of protons | 11 | 11 | | # of neutrons | 1 | 9 | | # of electrons | 11 | 11 | ### Selen…
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which of the following models best demonstrates a balanced chemical equ…
F. <The model with 1 white diatomic molecule, 2 dark diatomic molecules reacting to form 2 molecules with 1 white and 2 dark atoms each>
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19/20 which is the correct formula for: three hydrogen (h) one sulfur (…
None of the provided options match the correct formula $\text{H}_3\text{SO}_4$. The options listed are $\text{H}_2\text{SO}_4$, $\text{HSO}_4$, $\text{H}_4\text{S}_3\text{O}$, and…
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name: eliq perez date: february 3,2028 day 1 complete the terms and ans…
Melting ### Question 2
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lead has a density of 11.3 g/ml and a mass of 282.5 g. what is its volu…
25 mL (corresponding to the option "25 mL")
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temperature (°c) 0 10 20 30 40 50 60 70 80 90 100 57°c 33°c 75°c 94°c c…
25 mL (corresponding to the option "25 mL") ### For the temperature - related multiple - choice question (if we assume it's about the boiling point or some property of $SO_2$ from…
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directions: watch the video carefully and complete the guided notes as …
1. Chemical Bond Basics 1. transfer; share; stable 2. stable 2. Ionic Bonds 3. transferred 4. cations; anions 5. crystal lattice 6. high 7. dissolved in water; melted 3. Covalent …
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the diagram below is a model of two solutions. each green ball represen…
Solution A
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everything around us is made of matter—your clothes, the trees, even th…
2. C. in order to explain that air is made of atoms that take up space even though air is invisible 3. C. The atoms in gas move the fastest
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redox practice problems indicate the oxidation states of each of the el…
Na: +1, O: -2, H: +1 ### Problem 2: Oxidation State of HBr
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9. the product fe(scn)₃ produces a deep red color in solution. explain …
The amount of the limiting reactant (either $\ce{Fe^{3+}}$ or $\ce{SCN^{-}}$ in the reaction to form $\ce{Fe(SCN)_{3}}$) determines the maximum amount of $\ce{Fe(SCN)_{3}}$ that c…
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coal is a major part of the economy in virginia, and it has many everyd…
A. Chemical energy is released as thermal energy.
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dilution 1. how much concentrated 18m sulfuric acid is needed to prepar…
\( 83.3 \, mL \) ### Question 2
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2. nitrogen oxides: definition/description\thow is nh₃ made?\thow is ni…
To answer these questions, we'll address each compound (Nitrogen Oxides, Carbon Monoxide, Ozone) by researching their properties, production, and effects. Here's a breakdown: ### …
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across 4. particles of rock or naturally occuring materials 7. rocks be…
## Across: 4. Sediment 7. Weathering 8. Rock 9. Metamorphic rock 10. Texture 13. Geology 14. Lava 15. Composition ## Down: 1. Mineral 2. Sedimentary rock 3. Rock cycle 5. Stratifi…
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8. a student mixes 29.1 g of kscn with 16.2 g of fecl₃. a. identify the…
### Part a: Identify the limiting reactant First, we need to write the balanced chemical equation for the reaction between \( \text{KSCN} \) and \( \text{FeCl}_3 \). The reaction …
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select the word that means large. farmers can use science to improve th…
substantial
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across 3. a substance that dissolves another substance. 5. material tha…
Down 1: Condensation
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redox mixed practice ws l directions: answer the following questions, u…
- \( \text{Li} \): \( +1 \) - \( \text{S} \): \( +6 \) - \( \text{O} \): \( -2 \) ### Problem 2: Assign Oxidation Numbers to \( \text{NO}_3^- \)
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sam is building a campfire while camping with his family. sams younger …
b. Chemical energy in the log is converted to heat and light energy.
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write the formula of this compound antimony tribromide ○ sbbr₃ ○ abr₂ ○…
A. \( \text{SbBr}_3 \) ### Chlorine Dioxide Formula Question
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question 10 0.5 pts name this compound ph₃ ○ phosphorus trihydogen ○ ph…
C. Phosphorus Trihydride ### Question 11
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the second step to naming a covalent compound is the second element is …
The second element is named as anion using the suffix ide ### Second Question (Telling Number of Atoms in Covalent Compound)
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go to the website: http://www.kentchemistry.com/links/naming/namecov.ht…
A. The first element is named first using the elements name
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match the term with its definition. polar covalent bond choose choose n…
- Polar covalent Bond: when atoms are shared unequally in a covalent bond - Nonpolar covalent bond: a type of chemical bond that is formed when electrons are shared equally betwee…
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question 5 0.5 pts which element shown is doubled bonded? oxygen nitrog…
A. Oxygen
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which element shown in the video is a single bonded element? oxygen nit…
C. Chlorine ### Second Question (Which element is triple bonded?):
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why do atoms carry out covalent bonding? they bond together because the…
The correct option is: Their outer shell is not full which cause them to be unstable. ### Question 3 (Which element shown in the video is a single bonded element? - Note: Since th…
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go to the website: video link and watch the video. use this video to an…
A. Atoms bond together to complete their outer shell.
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26. all of the following changes to a metal are physical changes except…
b. rusting ### Question 27
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practice test f2 (pg 4 of 6) solubility equilibrium, ( k_{sp} ) ( ce{ca…
c. It is higher at a lower pH; there are more \(H^+\) ions in solution at low pH, so HF forms and shifts the equilibrium reaction above to the right. ### Question 23
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20. $k_{sp}=5.5\\times10^{-6}$ $\\ce{ca(oh)_{2}}\ ightleftharpoons\\ce{…
b. Less solid will dissolve, because the larger value of $[\ce{OH^-}]$ will cause the equilibrium position to lie farther to the left. ### Question 21
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practice test f2 (pg 3 of 6) solubility equilibrium, $k_{sp}$ rxn1: $pb…
d. \( K_{eq} = K_{sp1} / (K_{sp2})^2 \) ### Question 18
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hg₂i₂ ⇌ hg₂²⁺ + 2 i⁻ ( k_{sp} = \text{hg}_2^{2+}\text{i}^-^2 ) 16. a sa…
c. \( \text{s} = 2.3 \times 10^{-10} \, \text{M}; K_{sp} = [2.3 \times 10^{-10}][4.6 \times 10^{-10}]^2 \)
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use the following information to answer the next three questions 150 ml…
b. \( [\text{Sr}^{2+}] = 1.0 \times 10^{-3}\, \text{M}, [\text{F}^-] = 2.0 \times 10^{-3}\, \text{M} \) ### Question 14
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16. quiz limiting reactant 25 grams of silver (i) phosphide is added to…
Mass of $\text{AgOH}$: $\boldsymbol{75.5\ \text{grams}}$ Mass of $\text{Cr}_3\text{P}_2$: $\boldsymbol{22.0\ \text{grams}}$ (rounded to 3 significant figures)