化學
化學反應、化學計量、分子結構與元素性質。
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which of the following is not true of a compound? a it has a unique com…
d. It is always made up at least partly of carbon.
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what is a substance that consists of two or more elements? enter the an…
Compound
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what elements make up a water molecule? a two atoms of hydrogen and two…
c. two atoms of hydrogen and one atom of oxygen
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short for chlorofluorocarbons, cfcs are chemical compounds. scientists …
C. cause/effect.
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write, complete, and balance the following then perform the stoichiomet…
Balanced reaction: $2\text{Al(OH)}_3 ightarrow \text{Al}_2\text{O}_3 + 3\text{H}_2\text{O}$ Initial mass of aluminum hydroxide: 390 grams
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Question was provided via image upload.
Balanced equation: \( \boldsymbol{2\ce{NaBr} + \ce{Ca(OH)2} -> \ce{CaBr2} + 2\ce{NaOH}} \) Reaction type: \( \boldsymbol{DR} \) ### Problem 2: Balancing \( \boldsymbol{\ce{NH3 + H…
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recognizing nutritional classes match each nutrient class with its desc…
- proteins → build(s) and maintain(s) tissue - carbohydrates → provide(s) a major source of energy for the body - water → help(s) cleanse the body of toxins - vitamins → facilitat…
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determine the name of the ionic compounds listed below: 1. na₂s sodium …
### Part 1: Naming Ionic Compounds (Checking the Answers) For ionic compounds, we name them by stating the cation (metal) first and then the anion (non - metal, with its ending ch…
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write an inequality for each graph. chemistry the boiling point of a li…
\( x > 0.5 \) #### 2. Second Graph:
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which is the electron configuration for lithium?\ \\(1s^2\\)\ \\(2s^3\\…
C. \(1s^22s^1\)
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which is the electron configuration for zinc? 1s²2s²2p⁶3s²3p⁶4s²3d⁸ 1s²…
D. \(1s^22s^22p^63s^23p^64s^23d^{10}\) (assuming the last option is D; if options are labeled differently, adjust the label but keep the configuration text)
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if a shell can hold a maximum of 32 electrons, what is the value of n? …
4 (corresponding to the option "4")
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to show the electron configuration for an atom, what is the advantage o…
B. Orbital notation shows the spin of the electrons.
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which characteristic is given by the principal quantum number? orbital …
A. orbital size
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two representations of the distribution of electrons in the potassium a…
Model 2 because it shows an electron in the outermost ring.
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1s²2s²2p⁶3s² which diagram shows the correct distribution of electrons …
To determine the correct electron shell distribution for a magnesium atom: 1. **Total Electrons**: The electron configuration \(1s^2 2s^2 2p^6 3s^2\) gives \(2 + 2 + 6 + 2 = 12\) …
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consider the electron configuration. which element has this electron co…
chlorine (corresponding to the option "chlorine")
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which is the electron configuration for bromine?\ \\(1s^2 2s^2 2p^6 3s^…
A. \(1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}4s^{2}3d^{10}4p^{5}\)
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which is a characteristic of mixtures? ○ they are chemically bonded tog…
D. They can be separated by physical processes. (assuming the options are labeled A - D as is common, with the last option being the correct one)
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what can a drop of liquid mercury be described as? a pure substance and…
D. a pure substance and an element (assuming the last option is labeled D; if the original options were labeled differently, adjust the label to match the last option which is "a …
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the table shows the percentages of hydrocarbons that are found in a sam…
D. a mixture
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a student wants to know how many grams of water are made from 5.00 g ox…
B. \(\frac{2.0\space mole\space H_2O}{1.0\space mole\space O_2}\)
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bromine, a liquid at room temperature, has a boiling point of 58°c and …
D. pure substance
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which cannot be chemically broken down into simpler substances? compoun…
B. element
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which sample is a pure substance? zinc oxide sugar dissolved in water p…
A. zinc oxide
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hi, maya. when you submit this form, the owner will see your name and e…
\(\approx 44.6\ \text{g}\) (or more precisely, ~44.5 - 44.7 g depending on rounding) ### Question 2 (Incomplete, but assuming the typical stoichiometry problem for \( \text{O}_2 i…
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a gravel can be broken down into different kinds of substances by physi…
D. heterogeneous mixture
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a chemist is studying an unknown substance and could break the substanc…
D. pure substance
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which best describes an element? a pure substance a type of a mixture a…
a pure substance
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Question was provided via image upload.
Step 3 is incorrect because the mole ratio used is inverted. The correct mole ratio from the balanced equation \(2K + Cl_2 ightarrow 2KCl\) is \(\frac{2\ moles\ KCl}{1\ mole\ Cl_2…
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the chemical formula for an emerald is be₃al₂(sio₃)₆. an emerald can be…
a pure substance because it is a compound.
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8 how many moles of cu are needed to react with 5.8 moles of agno3? * c…
2.9 mol (corresponding to the option "2.9 mol")
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boron carbonate decomposes into boron oxide and carbon dioxide. how man…
15 ### Seventh Question (Mole Ratio of \( K_3PO_4 \) to \( KNO_3 \))
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5 which element has a molar mass of 30.974 g/mol? * (0.5 points) pallad…
C. Phosphorus
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4 stoichiometry is possible due to ______. * (0.5 points) newtons three…
D. Law of Conservation of Mass
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3 which is the mass of 8 moles of sodium chloride? * (0.5 points) 468 g…
468 grams
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2 how many atoms of nitrogen are there in 0.50 mol of (nh4)2co3? * 3.01…
\(6.02\times 10^{23}\) (the option with \(6.02\times 10^{23}\))
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1 how many moles of aluminium are needed to react completely with 1.2 m…
0.8 mol
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read the poem \the fog\ by carl sandburg. the fog comes on little cat f…
D. it doesn't follow a specific rhyme scheme.
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read the excerpt from the poem \the echoing green\ by william blake. th…
D. AABB
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a rhyme scheme is the pattern of rhyming lines in a poem. we can descri…
A. ABAB
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which of the following is one of the five most common elements associat…
C. nitrogen
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which type of bond forms between water molecules? capillary bond hydrog…
hydrogen bond
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which statement best explains why water is known as the universal solve…
Water has the ability to dissolve more substances than any other liquid.
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which bonds are found inside a water molecule, between hydrogen and oxy…
covalent bonds
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10. for each reaction below, identify the reaction type (synthesis, dec…
Synthesis #### Part b
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me n₂ gas is mixed with some o₂ gas, and the sketch below shows a repre…
For \( N_2 \): - Mole fraction: \( \boxed{0.222} \) - Partial pressure: \( \boxed{55.6} \) torr For \( O_2 \): - Mole fraction: \( \boxed{0.778} \) - Partial pressure: \( \boxed{1…
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me n₂ gas is mixed with some o₂ gas, and the sketch below shows a repre…
| gas | mole fraction | partial pressure (torr) | |-----|---------------|-------------------------| | \(N_2\) | \(0.222\) | \(55.5\) | | \(O_2\) | \(0.778\) | \(195\) |
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4.) how can water break apart rocks? 5.) how is chemical weathering dif…
Water breaks rocks via freeze - thaw (physical: water in cracks freezes, expands, and widens cracks; repeated cycles break rocks), abrasion (physical: moving water - carried parti…
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me n₂ gas is mixed with some o₂ gas, and the sketch below shows a repre…
| gas | mole fraction | partial pressure (atm) | |------|---------------|------------------------| | \( N_2 \) | 0.400 | 0.800 | | \( O_2 \) | 0.600 | 1.20 | (Note: The counts of …
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chemical and physical weathering weathering is the process by which roc…
The two types of weathering are physical weathering (also known as mechanical weathering) and chemical weathering. ### 2.
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chemical and physical weathering weathering is the process by which roc…
The two types of weathering are physical weathering (also called mechanical weathering) and chemical weathering. ### Question 2
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the ripple effect - the work of water across new york state surface int…
1. A canyon (formed by river erosion over time) 2. A flood (which can destroy habitats and human infrastructure) 3. Relating to space, position, or area; having to do with the phy…
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dinitrogen monoxide gas is collected at -12.0 °c in an evacuated flask …
mole: \(0.056 \text{ mol}\) mass: \(1.7 \text{ g}\)
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a reaction at 7.0 °c evolves 614. mmol of dinitrogen monoxide gas. calc…
\( 14.1 \)
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a chemical engineer must calculate the maximum safe operating temperatu…
\(396^{\circ}C\)
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a reaction between liquid reactants takes place at -9.0 °c in a sealed,…
\( 1.6 \)
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calculate to three significant digits the density of carbon monoxide ga…
$1.11$
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a sample of an unknown compound is vaporized at 200. °c. the gas produc…
\( 104\space g/mol \)
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methane gas and chlorine gas react to form hydrogen chloride gas and ca…
$28\ \text{mL}$
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methane gas and chlorine gas react to form hydrogen chloride gas and ca…
$28\ \text{mL}$
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fluorine gas and water vapor react to form hydrogen fluoride gas and ox…
$4.89\ \text{cm}^3$
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which molecule has three $^1$h nmr signals and will produce the followi…
D. \( \text{CH}_3\text{C(O)OCH}_2\text{CH}_3 \)
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the partial pressure of oxygen in the atmosphere is 159. torr. calculat…
mmHg: 159 mmHg atm: 0.209 atm
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the vapor pressure of solid iodine at 25 °c is 0.00186 atm. calculate t…
Vapor pressure in mmHg: \( \boldsymbol{1.41\ \text{mmHg}} \) Vapor pressure in torr: \( \boldsymbol{1.41\ \text{torr}} \)
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18 ______ used to ground up solids into powders r. pipet 19 ______ used…
To solve this, we match each description to the correct lab equipment: ### 18 **Explanation**: Grinding solids to powder is done with a mortar and pestle (not listed here? Wait, m…
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the vapor pressure of water at 5 °c is 0.008612 atm. calculate the vapo…
\( 0.8726 \) (Wait, no, wait, wait, 0.8726? Wait, no, let's check again. Wait, 0.008612 atm * 101.325 kPa/atm: 0.008612 * 101.325 = 0.8726109, which is 0.8726 when rounded to 4 si…
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what type of bond holds the hydrogen and oxygen atoms together in a wat…
hydrogen bond
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what type of bond holds the hydrogen and oxygen atoms together in a wat…
hydrogen bond
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what type of bond holds the hydrogen and oxygen atoms together in a wat…
covalent bond
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what type of bond holds the hydrogen and oxygen atoms together in a wat…
covalent bond
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complete the reactant or product in the following reactions. indicate t…
### 1. $\boldsymbol{\ce{Ca + Cl2 ightarrow}}$ ## Step1: Identify reaction type (combination) Calcium (Ca) and chlorine ($\ce{Cl2}$) combine. ## Step2: Write product (calcium chlor…
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match the definition from the 1st column to the best term in the 2nd co…
### Question 2 # Brief Explanations: The description is about a stand for heating reactions with a Bunsen Burner. A ring stand (not listed as an option here, but the correct term …
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use the codes below to determine the type of reaction s=synthesis d=dec…
S ### 2. \( \text{C}_5\text{H}_9\text{O} + \text{O}_2 ightarrow \text{CO}_2 + \text{H}_2\text{O} \) ## Step1: Identify reaction type Combustion (C) reactions involve a compound re…
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which statement is the most effective claim? ○ organic foods are a heal…
A. Organic foods are a healthier option than conventional foods.
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use the codes below to determine the type of reaction s=synthesis d=dec…
Balanced equation: \( 4\text{P} + 5\text{O}_2 ightarrow \text{P}_4\text{O}_{10} \), Reaction type: S (Synthesis) --- Let's solve problem 3: \( \text{HgO} ightarrow \text{Hg} + \te…
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the temperature is 80°f, find the temperature in celsius given the form…
The temperature in Celsius is $\frac{80}{3}^\circ\text{C}$ (or approximately $26.67^\circ\text{C}$)
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type of reaction synthesis or combination decomposition single replacem…
- **Synthesis or Combination**: \( A + B ightarrow AB \) (where \( A, B \) are elements/compounds, \( AB \) is a compound) - **Decomposition**: \( AB ightarrow A + B \) (where \( …
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matter: anything that occupies space and has mass. elements on the peri…
To determine the number of element types in each molecule/atom, we identify unique elements by their symbols (first letter capitalized, subsequent lowercase): ### 1. \( \boldsymbo…
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explaining trends in ionization energy the graphical representation of …
Magnesium has a lower ionization energy than aluminum. Ionization energy is the energy needed to remove an electron from an atom. Since Mg has lower ionization energy, it loses el…
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a friend in need dora sigerson shorter what is the rhyme scheme in the …
ABBBBBBBBBBA
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to avoid the influence of nearby atoms, measurements of ionization ener…
Ionization energy shows a periodic trend with atomic number: it generally increases across a period (e.g., from Li to Ne, Na to Ar) and decreases down a group (e.g., Li > Na > K >…
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isotope mass (amu) natural abundance b-10 10.013 19.78% → 0.1978×10.013…
10.81 amu
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the two half-reactions are given below.\\(\\ce{ag^+(aq) + e^- -> ag(s)}…
2
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consider the redox reaction below. ag⁺(aq) + zn(s) → zn²⁺(aq) + ag(s) b…
1
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consider the redox reaction below. ag⁺(aq) + zn(s) → zn²⁺(aq) + ag(s) b…
The number of electrons transferred in the zinc half - reaction is 2. The balanced zinc half - reaction is \(Zn(s)\to Zn^{2+}(aq)+2e^-\).
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what is the balanced chemical reaction occurring when aluminum is added…
A. \(2Al + 3H_2SO_4 ightarrow Al_2(SO_4)_3+3H_2\)
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the electrons are on the reactants side of the half-reaction. ?e⁻ + 2h⁺…
1
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3. isotopes vs. atomic mass a. define isotope in your own words. b. exp…
$10.81$ amu ---
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Question was provided via image upload.
A
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nitrate ion reacts with iodine, forming iodate ion and nitrogen dioxide…
A
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what is the balanced net ionic equation occurring when iron is added to…
D. $\boldsymbol{Fe + Cu^{2+} ightarrow Fe^{2+}+Cu}$
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the two half - reactions are given below. $2\\mathrm{e}^- + 2\\mathrm{h…
The coefficient of the hydroxide ion (\(OH^-\)) in the balanced net ionic equation is 2.
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modeling interconnected spheres read the paragraph, and then complete t…
Atmosphere → Biosphere
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review the fourth paragraph. that has a positive effect on a persons ph…
It explains why some people might not enjoy roller coasters.
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review the third paragraph. activities. 3 in addition to the sense of f…
Riding a roller coaster can give you a positive type of stress.
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the two half - reactions are given below. $2e^- + 2h_2o + hpo_3^{2-} \ …
again. For the first half - reaction (multiplied by 2): - P: 2 on left, 2 on right (good) - O: \(2\times3 + 4\times1=6 + 4 = 10\) on left (2 \(HPO_3^{2 - }\) has 6 O, 4 \(H_2O\) h…
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the redox reaction given below occurs in a basic solution. \\ce{hpo^2-_…
The number of electrons transferred in the \( \ce{N2H4} \) half - reaction (oxidation half - reaction) is 4.
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the redox reaction given below occurs in a basic solution. \\ce{hpo^2-_…
2
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reduction half - reaction $6\\ce{e-} + 4\\ce{h2o} + 2\\ce{mno4-} \ ight…
1 \(H_2O\) + 2 \(MnO_4^-\) + 1 \(Br^-\) \( ightarrow\) 2 \(MnO_2\) + 1 \(BrO_3^-\) + 2 \(OH^-\) So the coefficients are: \(H_2O\): 1, \(MnO_4^-\): 2, \(Br^-\): 1, \(MnO_2\): 2, \(…