化学
化学反応、化学量論、分子構造、元素の性質。
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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.
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butanol thermodynamics entropy consider the thermodynamics of the combu…
B. Statement I
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butanol thermodynamics volume of co₂ produced 25.0 g c₄h₉oh burns in ex…
56.3 L
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butanol thermodynamics moles of co₂ produced 25.0 g c₄h₉oh is burned in…
1.35 mol
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butanol thermodynamics reaction identification butanol, c₄h₉oh, is used…
Oxidation - reduction reaction
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butanol thermodynamics combustion of butanol butanol, c₄h₉oh, is used i…
D. \(C_4H_9OH(l) + 6O_2(g) ightarrow 4CO_2(g) + 5H_2O(g)\)
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the thermodynamics of ethanol gibbs free energy the thermodynamic data …
-1390. kJ/mol
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the thermodynamics of ethanol thermodynamic favorability the thermodyna…
The reaction will be favorable at all temperatures.
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the thermodynamics of ethanol gibbs free energy consider the following …
graph A
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the thermodynamics of ethanol change in entropy for combustion c₂h₅oh(l…
217.9 J/mol K (the option with 217.9 J/mol K)
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the thermodynamics of ethanol percent error the researchers calculated …
32% (corresponding to the option "32%")
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the thermodynamics of ethanol molar enthalpy of combustion through calo…
-1325 kJ/mol
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the thermodynamics of ethanol combustion reaction a researcher is worki…
B. $\ce{C_{2}H_{5}OH(l) + 3O_{2}(g) ightarrow 2CO_{2}(g) + 3H_{2}O(g)}$
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formation of butane from carbon dioxide and water thermodynamic favorab…
The reaction is never thermodynamically favorable.
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formation of butane from carbon dioxide and water gibbs free energy the…
5408 kJ
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formation of butane from carbon dioxide and water balanced equation mos…
A. $\ce{8CO2(g) + 10H2O(g) -> 2C4H10(g) + 13O2(g)}$
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formation of glucose thermodynamic favorability consider what you know …
The reaction is never thermodynamically favorable.
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formation of glucose gibbs free energy the formation of glucose from ca…
870 kJ (corresponding to the option "870 kJ")
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formation of glucose balanced equation most chemical reactions are cons…
C. $6\ce{CO2(g)} + 6\ce{H2O(g)} ightarrow \ce{C6H12O6(g)} + 6\ce{O2(g)}$
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using the data from the previous steps, calculate the standard gibbs fr…
\(+68\) (or more precisely, around \(+68.2\) but \(+68\) is acceptable based on significant figures or calculation steps)
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using the data below, calculate the enthalpy for the decomposition of n…
\(+112\)
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using the data below, calculate the entropy for the decomposition of no…
\(+147\)
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using the data from the previous steps, calculate the standard gibbs fr…
-105 (or -105.12 depending on precision, but -105 is a common approximation here)
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using the data from the previous steps, calculate the standard gibbs fr…
-105 (or more precise -105.1, depending on calculation; the key is the sign and magnitude. Using $T=298\ \text{K}$: $-140 - (298 \times -0.117) = -140 + 34.866 = -105.134 \approx …
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using the data below, calculate the enthalpy for the formation of rust,…
-140
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using the data below, calculate the entropy for the formation of rust, …
-117
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p₄o₁₀(s) + 6h₂o(l) → 4h₃po₄(aq) considering the thermodynamic data give…
D. Favorable at low T
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p₄o₁₀(s) + 6h₂o(l) → 4h₃po₄(aq) calculate the gibbs free energy change …
-356
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using the data from the previous steps, calculate the standard gibbs fr…
-1257 (or -1256.8, depending on rounding; typically rounded to whole number)
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calculate the enthalpy for the reaction below. 2al(s) + 3cl₂(g) → 2alcl…
-1408.4
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calculate the entropy for the reaction below. 2al(s) + 3cl₂(g) → 2alcl₃…
-507.3
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thermodynamics of ammonia formation of ammonia the formation of ammonia…
The reaction is exothermic.
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which statement is true for the reaction below? k₂o₂(s) → 2k(s) + o₂(g)…
The reaction will occur only at high temperatures.
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which statement is true for the reaction below?\ $\\ce{n_{2}o_{4}(g) \ …
B. The reaction will occur only at high temperatures.
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which of the following compounds would be most likely to decompose into…
$\ce{N2H4(l)},\Delta G^\circ_{\text{f}} = + 149.34\space kJ/mol$
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calculate the change in entropy for the reaction. 2no₂(g) ⇌ n₂o₄(g) sub…
\(-176.6\)
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calculate the standard entropy change for the industrial synthesis of u…
-424.13
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calculate the standard entropy change for the industrial synthesis of u…
\(-424.13\)
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calculate the change in entropy for the reaction. sicl₄(l) + 2h₂o(l) → …
-154
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use the energy diagram to answer these questions. what is the heat of r…
s: 1. Heat of Reaction: $\boldsymbol{-200\ \text{kJ/mol}}$ 2. Reaction Type: $\boldsymbol{\text{Exothermic}}$ 3. Forward Activation Energy: $\boldsymbol{\text{Yes, it's } 200\ \te…
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re is an energy diagram for the reaction: use the energy diagram to ans…
-200
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use the energy diagram to answer these questions. | what is the heat of…
To solve this, we need the energy diagram (which is not fully provided here, but we can explain the general approach): ### For "What is the heat of reaction?" The heat of reaction…
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multiple-choice question turning copper into wire. physical change chem…
A. Physical change
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multiple-choice question going from a solid to a gas in dry ice chemica…
B. Physical change
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multiple-choice question milk souring physical change chemical change r…
B. Chemical Change
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multiple-choice question turning water into hydrogen gas and oxygen gas…
Chemical change
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edpuzzle - chemical and physical changes (physical vs. chemical changes…
B. Chemical Change
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multiple-choice question condensing water vapor is what kind of change,…
A. Physical Change
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edpuzzle - chemical and physical changes (physical vs. chemical changes…
- sugar fermenting to alcohol - a nail rusting - newspapers burning
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a change is a __________ change if there is a change in the identity of…
B. chemical
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check all examples that are physical changes. water freezing to make ic…
- water freezing to make ice - paper cut to make a snowflake - peanuts turned into peanut butter
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a physical change is a change that does not involve a change in the ___…
identity (the option with "identity" should be selected)
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how can you tell that baking a cake produces a chemical change? it prod…
It combines the ingredients to form new substances.
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question 3 which of the following is an example of a purely chemical ch…
B. The explosion of fireworks.
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question 2 calculate the number of atoms for this formula, fe(no₃)₂.
9 (Note: The provided options do not include the correct calculated value; the accurate total number of atoms is 9)
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question 1 the 2 in the formula mgcl₂ is a (image of lewis structure: :…
B. Subscript
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t 4: the periodic table 1) write the atomic symbol for the element that…
To solve these problems, we use knowledge of the periodic table, including group and period numbering, and the properties of different element categories (alkali metals, transitio…
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element name,isotopic notation,mass # (whole numbers only),atomic mass …
| Element Name | Isotopic Notation | Mass # | Atomic Mass | Atomic # | # of protons | # of electrons | # of neutrons | |--------------|-------------------|--------|-------------|-…
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select the correct answer from each drop - down menu. which material is…
cancer
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drag the tiles to the correct boxes to complete the pairs. match the st…
- high tensile strength, can be pre - fabricated, but is prone to corrosion → steel - durable, abundantly available, and reusable if used with lime mortar → brick - organic materi…
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complete the following statements using the ph scale provided when nece…
0, 14, acidity (but wait the word bank has "acidic" (adjective) and "alkalinity" (noun). Wait, maybe the third blank is "alkalinity" no. Wait, the pH scale indicates the acidic or…
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teacher demo: synthesis 1. magnesium __mg + __o₂ → _______ 2. salt __na…
$2$Mg + $1$O₂ → $2$MgO #### 2. Salt
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disassociate in water found in foods like lemon juice, vinegar, and cof…
To solve this acid - base classification problem, we analyze each property: ### Acids (1/3) - **Dissociate in water**: Acids dissociate in water to produce $H^+$. - **Found in foo…
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fill in the blank question byron first learned how to pedal a tricycle …
schema
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5. write the chemical equation for the synthesis of ammonia (nh₃) from …
The chemical equation for the synthesis of ammonia is $\ce{N2 + 3H2 <=>[\text{High Temperature, Pressure, Catalyst}] 2NH3}$ (the equilibrium arrow is used as it's a reversible rea…
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multiple choice question piaget called complex cognitive structures tha…
B. schemes
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complete the following paragraph to correctly describe how water associ…
1. Due to water's \boxed{polarity}, it is capable of dissolving a great number of substances. 2. A \boxed{solution} contains a dissolved substance called a \boxed{solute}. 3. In a…
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which of the following best describes the term \sciatica\? burning or a…
Burning or aching posterior thigh pain caused by ischemic changes of and/or neuroinflammation of the Sciatic nerve.
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5 maricruzs family goes on an autumn campout to a local state park. dur…
5. C. the clouds forming rain from water vapor 6. D. The penny on the left has undergone a chemical change on its surface 7. C. when a white substance begins to form at the bottom…
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day 3 - 8th grade science staar review name date 9. which of the follow…
9. B. $\text{C}_6\text{H}_{12}\text{O}_6 + 6\text{O}_2 ightarrow 6\text{CO}_2 + 6\text{H}_2\text{O}$ 10. A. The mass of the products is equal to the mass of the reactants. 11. C. …