化学
化学反应、化学计量、分子结构与元素性质。
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describing elements use the drop - down menu to complete the sentence. …
compound
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5. banana mixed two substances together. it first smells like flowers a…
B. Diagram B
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periodic table of the elements e h d b c g f a (1 pt each) match the qu…
1. 1 - A 2. 2 - B 3. 3 - H 4. 4 - C 5. 5 - I 6. 6 - E 7. 7 - I 8. 8 - E 9. 9 - I 10. 10 - H 11. 11 - A 12. 12 - F 13. 13 - F 14. 14 - B 15. 15 - H
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it is composed of nitrogen. it is composed of oxygen. it is composed of…
It is composed of a mixture of gases.
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identifying ions what ion is formed when an atom of mercury (hg) loses …
$\boldsymbol{Hg^{+2}}$ (Option: $\boldsymbol{Hg^{+2}}$)
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instructions: show all work and include units in every step. 1. how man…
1. $1.00\ \text{mol}$ 2. $1.00\ \text{mol}$ 3. $1.00\ \text{mol}$ 4. $1.00\ \text{mol}$ 5. $12.8\ \text{g}$ 6. $139\ \text{g}$ 7. $88.0\ \text{g}$ 8. $71.0\ \text{g}$
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describing isotopes what is the mass number of the isotope lithium - 7?…
Mass number of lithium-7: $7$ Number of neutrons in lithium-8: $5$
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select the correct answer. why might two elements possess similar chemi…
A. They belong to the same group of the periodic table.
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co₂(g) + 2so₂(g) → 3o₂(g) + cs₂(g) considering the thermodynamic data g…
C. Favorable at high T
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formation of glucose balanced equation most chemical reactions are cons…
B. \(6CO_2(g)+6H_2O(g) ightarrow C_6H_{12}O_6(g)+6O_2(g)\)
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directions: complete the chart below. | element | number of valence ele…
| Element | Number of Valence Electrons | # of electrons gained or lost to fill outer energy level | Charge (Oxidation Number) | |---------------|------------------------------|--…
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which of the following compounds would be most likely to decompose into…
$\ce{N2H4(l)}$, $\Delta G^\circ\text{f}= + 149.34\ \text{kJ/mol}$
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which statement is true for the reaction below? $2\\ce{o_3}(g) \ ightar…
The reaction will occur at all temperatures.
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calculate the change in entropy of liquid bromine using the data below.…
+152
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calculate the change in entropy for the reaction. sicl₄(l) + 2h₂o(l) → …
\(-154\)
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in which example is the entropy of the final state greater than the ent…
Dry ice (solid \( \text{CO}_2 \)) sublimes.
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12. what is the difference between an atom and an element? 13. why is t…
An atom is the smallest particle of matter that retains the chemical properties of an element. An element is a pure substance made up of only one type of atom (all atoms of an ele…
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which substance will have the greatest standard molar entropy value? h₂…
Rn(g)
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1. diagram sodium has 11 protons and 11 neutrons in its nucleus. draw a…
Draw a central nucleus (label: 11 protons, 11 neutrons). Draw three energy levels (circles) around it. First level: 2 electrons, second: 8 electrons, third: 1 electron. Label each…
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calculate the enthalpy of vaporization, the energy required to convert …
+44
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calculate the standard reaction enthalpy for the reaction between clf₃ …
+480.2
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which of the reactions below is a formation reaction? ½n₂(g) + ³⁄₂h₂(g)…
$\boldsymbol{\frac{1}{2}\text{N}_2(\text{g}) + \frac{3}{2}\text{H}_2(\text{g}) ightarrow \text{NH}_3(\text{g})}$ (the first option)
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which of the reactions below is a formation reaction? h₂(g) + ½cl₂(g) →…
$\boldsymbol{\ce{H2(g) + 1/2Cl2(g) -> HCl(g)}}$ (the first option: $\ce{H2(g) + 1/2Cl2(g) -> HCl(g)}$)
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calculate the enthalpy for this reaction. \\ce{ch3cl + o2 -> co + hcl +…
\(-404\)
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calculate the enthalpy for this reaction. 2hg + cl₂ → hg₂cl₂ use the fo…
\(-265\)
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143 kj of energy was released during the reaction, raising the temperat…
\( \approx 2.79 \)
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the combustion of 3.00 grams of octane, c₈h₁₈, in a bomb calorimeter re…
\(-143\) (or more precisely \(-143.4\) depending on sig fig interpretation, but 3.00 has 3 sig figs, so \(-143\) or \(-143.4\) if considering more decimals)
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0.50 g of mg reacts with excess oxygen in a bomb calorimeter. the overa…
-590 (or -592, depending on significant figures calculation; but following the steps, the precise calculation gives approximately -591.7, which rounds to -590 or -592 based on sig…
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2naoh + h₂so₄ → 2h₂o + na₂so₄ 50.0 ml of 0.50 m h₂so₄ is added to 60.0 …
-24.3 kJ/mol (or more precise -24.33 kJ/mol, depending on rounding)
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understand main ideas 1. diagram sodium has 11 protons and 11 neutrons …
The number of neutrons in beryllium - 9 is 5. The calculation is done using the formula for atomic mass ($A=p + n$), where $A = 9$ (atomic mass of beryllium - 9) and $p = 4$ (numb…
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select the correct answer? the ph scale measures the acidity of a liqui…
A. 0.001
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2naoh + h₂so₄ → 2h₂o + na₂so₄50.0 ml of 0.50 m h₂so₄ is added to 60.0 m…
\(-580\) (or more precisely \(-579.96\))
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2naoh + h₂so₄ → 2h₂o + na₂so₄ 50.0 ml of 0.50 m h₂so₄ is added to 60.0 …
\(115.5\)
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11. $c_6h_{12}o_6 + o_2 \ ightarrow co_2 + h_2o$ 12. $al + o_2 \ ightar…
11. $\mathrm{C_6H_{12}O_6 + 6O_2 ightarrow 6CO_2 + 6H_2O}$ 12. $\mathrm{4Al + 3O_2 ightarrow 2Al_2O_3}$ 13. $\mathrm{2NaOH + H_2SO_4 ightarrow Na_2SO_4 + 2H_2O}$ 14. $\mathrm{2C_8…
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hcl + naoh → nacl + h₂o 25.0 ml of 1.00 m hcl is added to 75.0 ml of 1.…
\(-148\) (or more precisely \(-148.4\)) kJ/mol (Note: If we calculate \(\frac{-3710\space J}{0.0250\space mol}=\frac{-3.710\space kJ}{0.0250\space mol}=-148.4\space kJ/mol\), so t…
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hcl + naoh → nacl + h₂o 25.0 ml of 1.00 m hcl is added to 75.0 ml of 1.…
\(-3706\) (or \(-3705.66\))
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types of chemical reactions balance each of the following reactions. th…
1. (Already balanced) synthesis 2. $2H_2O ightarrow 2H_2 + O_2$; decomposition 3. (Already balanced) single replacement 4. $2CO + O_2 ightarrow 2CO_2$; synthesis 5. $2HgO ightarro…
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hcl + naoh → nacl + h₂o 25.0 ml of 1.00 m hcl is added to 75.0 ml of 1.…
102
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the heat of solution, $q_{soln}$, is +27 j for the dissolution of a sol…
The water temperature decreases as the endothermic dissolution absorbs heat from the water.
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the water absorbs about 2120 j and the calorimeter absorbs about 22 j. …
\(-2142\)
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a 25.5 g piece of metal with a temperature of 105.00 °c is dropped into…
\(+21.7\)
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chapter 4: parts of the atom & bonding guided reading - short answer 1.…
The three particles that make up an atom are protons, neutrons, and electrons. Protons and neutrons are located in the nucleus (the central part) of the atom, while electrons are …
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type the correct answer in the box. calculate the density of the substa…
3.9
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select the correct answer from each drop - down menu. mendeleev’s table…
the atomic numbers of the elements
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select the correct answer from each drop - down menu. mendeleevs table …
it could accommodate new elements
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the final temperature at equilibrium is 25.00 °c. the heat is supplied …
\( \boldsymbol{102.5} \) (or more precisely \( 102.47 \)) \(^{\circ}C\) (depending on the required precision, the calculation gives approximately \( 102.5^{\circ}C \) when rounded…
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a 50.0 g piece of granite was immersed in 28.3 g of water. the water an…
+2957 J (or more precisely +2957.35 J, depending on significant figures)
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elements of each group in the periodic table have certain characteristi…
- "very reactive nonmetals" → halogens - "don't react naturally with other elements" → noble gases - "solids at room temperature" → alkali metals
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drag each tile to the correct location. classify each property as inten…
- Intensive Property (Propiedad Intensiva): reactivity with acid - Extensive Property (Propiedad Extensiva): volume, length
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you decide to use aluminum \ice cubes\ to cool your juice. what is the …
-15,000 J
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what is the energy change for the thermite reaction when 11.0 g al reac…
-173 kJ (corresponding to the option: -173 kJ)
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8. which is a general characteristic of metals? a. poor conductors of h…
8. C. Good conductors of electricity 9. B. Metals from nonmetals 10. D. Valence electrons 11. A. Dalton 12. B. Covalent bond 13. C. Nonmetals 14. C. Protons and neutrons
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which thermochemical equation corresponds to the graph? energy diagram …
B. \( \text{A} + 2\text{B} ightarrow \text{AB}_2 + \text{Energy} \) (assuming the middle option is B, as per typical multiple - choice layout with the second option being the corr…
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elements and the periodic table assessment 1. what is the center of an …
1. B. Nucleus 2. C. Proton 3. D. Chadwick 4. A. Protons 5. B. In the energy levels surrounding the nucleus 6. C. Plum pudding model 7. C. Similar chemical properties
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which of the following is not an observable or measurable outcome for a…
The temperature of the water in the beaker goes down.
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two systems, one with 50.0 g of aluminum and the other 100.0 g of alumi…
The heat added is greater for the 100.0 g Al system. (Corresponding option: The heat added is greater for the 100.0 g Al system.)
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select the correct answer. which statement best describes how a compoun…
A. A compound contains two or more elements in a fixed proportion
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hematite is a naturally occurring mineral and a common form of iron ore…
B. The hematite particles rearrange to form a new substance.
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select the correct answer. which statement describes both homogeneous m…
C. Their components can be separated by physical processes.
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7. can two elements be used as reactants for a synthesis reactions? if …
Yes. Example: \( \ce{2H_2 + O_2 -> 2H_2O} \) (hydrogen and oxygen, elements, synthesize water). ### Question 8
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select the correct location. which part of the periodic table would con…
The light - blue colored block (the bottom block in the diagram, representing inner transition metals: lanthanides and actinides)
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select the correct answer. a chemist divides a large sample of a mixtur…
C. heterogeneous mixture
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0 p₄ + 0 f₂ → 0 pf₃
Left box: $1$ $\text{P}_4$ + $6$ $\text{F}_2$ Right box: $4$ $\text{PF}_3$ Balanced equation: $\text{P}_4 + 6\text{F}_2 ightarrow 4\text{PF}_3$
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0 so₃ → 0 so₂ + 0 o₂
$2\text{SO}_3 ightarrow 2\text{SO}_2 + \text{O}_2$
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type the correct answer in the box. round your answer to the nearest hu…
63.55
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0 pcl₃ → 0 p₄ + 0 cl₂
Left box: $4\text{PCl}_3$ Right box: $\text{P}_4 + 6\text{Cl}_2$
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2 n₂ + 0 o₂ → 2 n₂o not balanced
The balanced chemical equation is $\boldsymbol{2\text{N}_2 + \text{O}_2 = 2\text{N}_2\text{O}}$
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× not balanced try again hide why 1 n₂ + 3 o₂ → 5 n₂o
The balanced chemical equation is $\boldsymbol{2N_2 + O_2 ightarrow 2N_2O}$
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select the correct answer. bromine (br) belongs to the halogen family. …
D. 7
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select the correct answer. what is the si unit used to measure the temp…
D. kelvin
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why does $ce{ch_3oh}$ have a higher boiling point than $ce{ch_4}$? expl…
Because \( \text{CH}_3\text{OH} \) can form hydrogen bonds, and \( \text{CH}_4 \) cannot.
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which of the following species are capable of hydrogen bonding among th…
$\ce{CH_{3}COOH}$, $\ce{H_{2}O}$, $\ce{C_{2}H_{5}COOH}$
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acetic acid ($ce{hc_{2}h_{3}o_{2}}$) is an important ingredient of vine…
\(0.107\)
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how would you prepare 80.0 ml of 0.800 m hno₃ from a stock solution of …
16.0
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why? recognizing patterns allows us to predict future behavior. weather…
- (s): solid - (l): liquid - (g): gas - (aq): dissolved in water ### Question 2
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during a camping trip, students lit a fire using dry wood. as the fire …
A. The fire transformed chemical energy in the wood into thermal and light energy.
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which one of the following substances would have the lowest melting poi…
A. \( \text{Cl}_2 \)
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the illustration depicts the formation of an ionic chemical bond betwee…
D. transferred electron provides both elements with a full outer energy level.
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identify which bond type is present in each of the compounds. caco₃ ion…
To determine the bond type (ionic or covalent) for each compound, we analyze the nature of the atoms involved: ### 1. \( \boldsymbol{\ce{CaCO3}} \) - **Ionic Bond**: Calcium (\( \…
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10. how many grams of o₂ will be formed from 3.76 grams of kclo₃? \\(\\…
$1.48$ g $\text{O}_2$ --- ### Problem 11
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a student places a clear, effervescent tablet (like alka - seltzer) int…
This is a chemical change. The formation of gas bubbles (a new substance, carbon dioxide) and the measurable temperature drop (indicating an endothermic chemical reaction) confirm…
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a student places a clear, effervescent tablet (like alka - seltzer) int…
This is a chemical change. - **Claim**: The reaction of the effervescent tablet with water is a chemical change. - **Evidence**: Bubbles (gas) are produced, and the water temperat…
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ngss ms mod j u1l2 passage changes in temperature reggie puts a beaker …
To solve this, we recall the phase change temperatures of water: ### Liquid to Gas (Boiling): - At sea level, water boils at \( 100^\circ \text{C} \), but at high elevation (lower…
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item 8 ngss ms mod 1 u1l2 passage changes in temperature gegge puts a b…
a purely physical change because it will change state
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writing chemical formulas question of the day? what number is never use…
The number never used as a subscript in a chemical formula is 1.
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select the correct answer. which verb correctly completes the sentence?…
C. busqué
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oxygen is acting as an oxidizing agent in all of the following reaction…
C. \( 2 F_2(g) + O_2(g) ightarrow 2 OF_2(g) \)
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oxygen is acting as an oxidizing agent in all of the following reaction…
C. \(2 F_2(g) + O_2(g) ightarrow 2 OF_2(g)\)
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oxygen is acting as an oxidizing agent in all of the following reaction…
C. \(2 F_2(g) + O_2(g) ightarrow 2 OF_2(g)\)
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oxygen is acting as an oxidizing agent in all of the following reaction…
C. \(2 F_2(g) + O_2(g) ightarrow 2 OF_2(g)\)
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oxygen is acting as an oxidizing agent in all of the following reaction…
C. \(2\ F_2(g)+O_2(g) ightarrow2\ OF_2(g)\)
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oxygen is acting as an oxidizing agent in all of the following reaction…
C. \(2 F_2(g) + O_2(g) ightarrow 2 OF_2(g)\)
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oxygen is acting as an oxidizing agent in all of the following reaction…
C. \( 2\ F_2(g) + O_2(g) ightarrow 2\ OF_2(g) \)
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oxygen is acting as an oxidizing agent in all of the following reaction…
C. \(2\ F_2(g) + O_2(g) ightarrow 2\ OF_2(g)\)
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oxygen is acting as an oxidizing agent in all of the following reaction…
C. \(2 F_2(g) + O_2(g) ightarrow 2 OF_2(g)\)
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oxygen is acting as an oxidizing agent in all of the following reaction…
C. \(2 F_2(g) + O_2(g) ightarrow 2 OF_2(g)\)
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oxygen is acting as an oxidizing agent in all of the following reaction…
C. \( 2 F_2(g) + O_2(g) ightarrow 2 OF_2(g) \)
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oxygen is acting as an oxidizing agent in all of the following reaction…
C. \(2 F_2(g) + O_2(g) ightarrow 2 OF_2(g)\)
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butanol thermodynamics enthalpy of formation reaction the enthalpy of f…
4C(s, graphite) + ½O₂(g) + 5H₂(g) → C₄H₉OH(l) (the third option)
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butanol thermodynamics spontaneous conditions consider the thermodynami…
It is favorable at all temperatures.