化學
化學反應、化學計量、分子結構與元素性質。
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3.0 m hydrochloric acid is poured over an iron nail and a reaction happ…
A. Chloride ion becomes chlorine gas.
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what is the balanced chemical reaction occurring when zinc metal is add…
$\ce{Zn + 2HF -> ZnF2 + H2}$ (the option: $\boldsymbol{\ce{Zn + 2HF -> ZnF2 + H2}}$)
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2nh₄oh + 1kal(so₄)₂ + h₂o → 2al(oh) + (nh₄)₂so₄ + koh +
# Explanation: ## Step1: Identify reactants and products Reactants: \(2\text{NH}_4\text{OH}\), \(\text{KAl(SO}_4\text{)}_2\), \(\text{H}_2\text{O}\) Products: \(\text{Al(OH)}_3\),…
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i need a hint 7.89×10²⁴ molecules h₂o × (a units / c units) = choices: …
The value of A is \(1\) (mole) and the value of C is \(6.02\times 10^{23}\) (molecules \(H_2O\)). So in the given format, A is \(1\) and C is \(6.02\times 10^{23}\). If we conside…
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use a system of equations to solve this problem. a chemist currently ha…
7.5 L of 5% solution 2.5 L of 25% solution
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8.77 moles × (6.022 × 10²³ sodium ions) / 1 mole =
\(5.28\times10^{24}\) (or \(5.281394\times10^{24}\)) sodium ions (the answer can be rounded to an appropriate number of significant figures, here 8.77 has three significant figure…
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34.29 ml of 0.15 m hbr reacts with a 0.20 m solution of methylamine. wh…
\(25.72\)
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the weak base methylamine, ch₃nh₂, is used in the production of insecti…
1
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patrick makes his solution and standardizes it using khp (204.22 g/mol)…
0.110 (or more precisely, after detailed calculation: $\frac{0.7863}{204.22\times0.03510} \approx 0.110\ M$)
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patrick needs to make 100. ml of 0.15 m naoh in order to conduct an exp…
0.60
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what is the purpose of an indicator in a titration experiment? to deter…
A. to determine the end point
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what is the end point in a titration? the point where the indicator cha…
A. The point where the indicator changes color.
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what volume of 1.25 m hcl reacts with 13.49 g al in the reaction below?…
1.2
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what volume, in ml, of 0.35 m ca(no₃)₂ is required to completely react …
\( 107 \) (or more precisely, using exact calculation: \( \frac{0.75 \times 50.0}{0.35} \approx 107.14 \), rounded to appropriate sig figs, 107 mL)
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a container holds 1.0 l of 0.5 m alcl₃ solution. how many moles of al³⁺…
0.5 moles \( \text{Al}^{3+} \) (corresponding to the option: 0.5 moles \( \text{Al}^{3+} \))
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a container holds 1.0 l of 0.5 m alcl₃ solution. how many moles of cl⁻ …
1.5 moles Cl⁻
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which equation describes the dissociation of alcl₃ as it dissolves in w…
A. \( \text{AlCl}_3 ightarrow \text{Al}^{3+} + 3\text{Cl}^- \)
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a container holds 2.0 l of 2.0 m na₂co₃ solution. how many moles of co₃…
4.0 moles \( \text{CO}_3^{2-} \) (the first option: 4.0 moles \( \text{CO}_3^{2-} \))
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a container holds 2.0 l of 2.0 m na₂co₃ solution. how many moles of na⁺…
8.0 moles \( Na^+ \) (the first option: 8.0 moles \( Na^+ \))
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which equation describes the dissociation of na₂co₃ as it dissolves in …
A. $\ce{Na_{2}CO_{3} ightarrow 2Na^{+} + CO_{3}^{2-}}$
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a popular sports drink has 30.43 g of the sugar sucrose in 500. ml of t…
\( 0.178 \)
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john measures out the required 150 ml of 6% h₂o₂ in a graduated cylinde…
150
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john dilutes some 6% (or 1.76 m) h₂o₂ to 3% (or 0.88 m) in order to cre…
150
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hydrogen fuel cells are a promising source of energy. which of these is…
water
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predict the products for the reaction. solutions of acetic acid and pot…
$\ce{KC2H3O2(aq) + H2O(l)}$ (the option: $\ce{KC2H3O2(aq) + H2O(l)}$)
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what is the balanced net ionic equation for the reaction below? hi(aq) …
A. \(H^+(aq) + OH^-(aq) ightarrow H_2O(l)\)
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2nh₄oh + kal(so₄)₂ + h₂o → 2al(oh) + (nh₄)₂so₄ + koh +
To balance the chemical equation \( 2NH_4OH + KAl(SO_4)_2 + H_2O ightarrow Al(OH)_3 + (NH_4)_2SO_4 + KOH + H_2O \) (note: there's a duplicate \( H_2O \) which we'll address), we f…
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what is the net ionic equation for the reaction between calcium nitrate…
$\boldsymbol{\ce{Ca^{2+} + SO4^{2-} -> CaSO4}}$ (the fourth option: $\ce{Ca^{2+} + SO4^{2-} -> CaSO4}$)
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as labeled in this diagram, which layer contains all naturally occurrin…
D. The outermost layer (labeled D, the crust)
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what is the insoluble product of this precipitation reaction? zn(no₃)₂(…
B. \(ZnCO_{3}\)
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what is the balanced chemical equation occurring when lithium carbonate…
$\ce{Li2CO3(s) + 2HCl(aq) -> 2LiCl(aq) + H2O(l) + CO2(g)}$ (the third option)
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question 5 (2.5 points) dr. tucker is a developmental psychologist. whi…
D. How do brain chemicals influence sexual behavior in young adults? ### Question 6
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Question was provided via image upload.
Milo has a chemistry lecture each Monday. He reviews each Monday’s material the following Wednesday and Friday. ### Second Question (Descartes' View)
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what is the balanced chemical reaction occurring during the reaction of…
B. $\ce{NH4Cl + LiOH ightarrow NH3 + LiCl + H2O}$
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which of these depicts the balanced equation for the neutralization of …
C. $\ce{KOH + HNO_{3} -> KNO_{3} + H_{2}O}$ (or the option labeled "KOH + HNO₃ → KNO₃ + H₂O")
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which of these is not a strong base? koh al(oh)₃ naoh ca(oh)₂
B. $\ce{Al(OH)_{3}}$
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which of these is not a strong acid? hclo₄ hclo₃ hclo₂ hcl
\(HClO_2\) (chlorous acid)
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what mass of na₂so₄ is required to generate 12.0 g baso₄? molar mass ba…
\boxed{7.30}
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what mass of bacl₂ is required to generate 12.0 g baso₄? molar mass bas…
10.7 g (or more precisely 10.71 g)
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the reaction below produces a solid that some ct scans use as a marker.…
\(233.4\)
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what mass of aluminum sulfate is required to generate 10.0 grams of alu…
\( 14.0\ \text{g} \) (or approximately \( 14\ \text{g} \))
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what mass of sodium phosphate is required to generate 10.0 grams of alu…
\( 13.4 \) (rounded to three significant figures, or more precisely, the calculation gives approximately \( 13.4\ \text{g} \))
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aqueous solutions of sodium phosphate and aluminum sulfate combine, for…
$121.95$
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a variety of ions including $ce{na+}$, $ce{k+}$, $ce{nh^+_4}$, $ce{pb^2…
B. PbS
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which of these is the correct balanced chemical equation, including sta…
D. \(SrCl_{2}(aq)+K_{2}SO_{4}(aq) ightarrow SrSO_{4}(s)+2KCl(aq)\) (assuming the last option is D, if the options are labeled as A, B, C, D with the last one being this equation)
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identify the electrolyte capacity of the material in the particle model…
Weak Electrolyte
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which equation represents a solid ionic compound dissolving in water to…
C. \(Ca(NO_3)_2 ightarrow Ca^{2+} + 2NO_3^-\)
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hydrogen fuel cells are a type of alternative energy. these cells are e…
Water
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unit 4 - applications of derivatives (4.1-4.3) assignment carbon-14 dat…
$-0.0027$ grams per year
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compare the student text source: carolyn williams, \a natural label on …
Yes, because it fails to cite the source.
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some ingredients long used by perfumers to create fragrances have been …
- The use of oakmoss was restricted. : The French company Mane created a replacement. - The use of hydroxycitronellal was restricted. : Swiss perfumer Andy Tauer blended substitut…
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biomass energy can be a sustainable carbon - neutral source of energy. …
We burn it (combustion) or chemically convert it to biofuel.
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what best explains whether bromine (br) or neon (ne) is more likely to …
Bromine forms covalent bonds because it has seven valence electrons, but neon has eight valence electrons and is stable, so it does not form covalent bonds.
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property compound a b c d melting point high low low high boiling point…
compounds D and A
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which ionic compound is used as a building material? salt limestone mag…
limestone
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name balancing equations worksheet balance the equations below using th…
Let's take the first equation: $\boldsymbol{\ce{N_{2} + O_{2} -> N_{2}O}}$ (the original might have a typo, assuming it's $\ce{N_{2}O}$ or $\ce{NO}$; let's correct to balancing $\…
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question a radioactive compound with mass 470 grams decays at a rate of…
$C = 470(1 - 0.03)^6$
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4) type the correct numbers in the blanks below. type in 1 if the coeff…
Balanced reaction coefficients: 1, 3, 2 Correct reaction for added heat: $\text{Fe} + 2\text{S} \stackrel{\Delta}{ ightarrow} \text{FeS}_2$
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bonus: how many atoms of hydrogen are found in 12.6 moles of water?
$1.52 \times 10^{25}$ hydrogen atoms
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1) choose the best answer. which type of reaction occurs when two eleme…
1. A. synthesis 2. C. combination 3. D. $\text{2KCl}(s) ightarrow \text{2K}(s) + \text{Cl}_2(g)$
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6) choose the best answer. which of the following reactions shows that …
6. $\boldsymbol{\text{O } \text{H}_2\text{O}_2 \xrightarrow{\text{Pt}} \text{H}_2 + \text{O}_2}$ 7. $\boldsymbol{\text{O } 2\text{H}_2\text{O}_2 ightarrow 2\text{H}_2\text{O} + \t…
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Question was provided via image upload.
1. Decomposition reaction: $\boldsymbol{2H_2O_2 ightarrow 2H_2O + O_2}$ 2. Drag-and-drop matches: - reaction in which heat is required: thermal decomposition - reaction in which a…
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10. how many grams of tin are found in 3.50 moles of tin?
$415.485\ \text{grams}$ (rounded to 415 grams or 415.5 grams for reasonable precision)
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10) choose all that apply. which two products complete the unbalanced d…
## For question 10: □ N □ C ☑ Na ☑ Cl₂ ## For question 11: □ NH ☑ N₂ □ H₂O ☑ H₂
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9. how many atoms of tin are found in 3.50 moles of tin?
$2.11 \times 10^{24}$ atoms of tin
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which of the following is a common impurity found in coal? sulfur silic…
sulfur
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8. convert 8.00 × 10²⁰ molecules of h₂ to moles.
$1.33 \times 10^{-3}$ moles of $H_2$
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7. what is the mass of 9.30 moles of sih₄?
$298.7346\ \text{g}$ (or rounded to $299\ \text{g}$ for 3 significant figures)
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6. how many moles are represented by 11.5 g of c₂h₅oh?
$0.250$ moles
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choose the best answer using the equation. \\( 2c_4h_{10}(g) + 13o_2(g)…
4. $\text{C}_4\text{H}_{10}(g)$, $\text{O}_2(g)$ 5. 13 6. gas
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3. choose the best answer. students observe the combustion reaction tak…
propane and oxygen
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1. choose the best answer. when the following equation is balanced, wha…
1. 5 2. Solid copper and silver nitrate, dissolved in water, react to form aqueous copper (II) nitrate and solid silver.
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9. choose the best answer. when the following equation is balanced, wha…
9. 2 10. $2\text{Mg}(s) + \text{O}_2(g) ightarrow 2\text{MgO}(s)$
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12. choose the best answer. when the following equation is balanced, wh…
11. The reaction will shift toward the products. 12. 3
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¿qué significa el 2 delante de nai? * hay 2 átomos de na hay 2 molécula…
B. Hay 2 moléculas de NaI ### Second Question: ¿Cuántos átomos de cloro hay en el lado reactivo?
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14. choose the best answer. which of these describes the law of conserv…
### Reaction Classifications: 1. $2\text{NH}_3 + \text{H}_2\text{SO}_4 ightarrow (\text{NH}_4)_2\text{SO}_4$: synthesis 2. $4\text{C}_5\text{H}_9\text{O} + 27\text{O}_2 ightarrow …
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15. choose the best answer. when the following equation is balanced, wh…
15. B. 3 16. D. $4\text{NH}_3 + 5\text{O}_2 ightarrow 4\text{NO} + 6\text{H}_2\text{O}$
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comprobar productos de la ecuación * nal cl₂ nacl yo₂ comprueba los rea…
- $NaCl$ - $Yo_2$ (si $Yo_2$ es $I_2$, producto de la reacción) ### 2. Comprueba los reactivos de la ecuación (Reacción: $\boldsymbol{2NaI + Cl_2 ightarrow 2NaCl + I_2}$)
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2nai + cl₂ → nacl + i₂ ¿esta ecuación está balanceada? * ○ no ○ sí comp…
A. No ### Second Sub - Question: Comprobar productos de la ecuación
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¿ cuántos átomos de azufre hay en una sola molécula de $\\ce{h_{2}so_{4…
A. 1
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¿qué afirmación describe el enlace entre el hidrógeno y el oxígeno en u…
Es covalente porque dos átomos de hidrógeno comparten un electrón con un átomo de oxígeno. ### Second Question (Nombre de $\ce{N2O4}$)
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use the following diagram to answer questions 54 to 56. 54. which of th…
C. \(\ce{Cr_{2}O^{2-}_{7} + 14H^{+} + 6Ag ightarrow 6Ag^{+} + 2Cr^{3+} + 7H_{2}O}\) ### Question 55
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3.4 cognitive development across the lifespan abstract thinking accommo…
1. accommodation 2. assimilation 3. conservation 4. concrete operational stage 5. crystallized intelligence 6. egocentrism 7. fluid intelligence 8. formal operational stage 9. obj…
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algunos elementos pueden combinarse para formar compuestos iónicos. ¿qu…
D. sodio ### Second Question (¿Qué afirmación describe el proceso mediante el cual un átomo de metal alcalino forma un enlace con un átomo de halógeno?)
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¿cuál es el papel de los electrones en la formación del cloruro de liti…
### Primera pregunta: # Breves Explicaciones: Para la formación del cloruro de litio (LiCl), el litio (metal alcalino) tiene 1 electrón en su nivel de valencia y tiende a perderlo…
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¿a qué grupo de la tabla periódica pertenece el estroncio? * ○ halógeno…
### Primera pregunta: # Breve Explicación: El estroncio (Sr) tiene número atómico 38 y su configuración electrónica es tal que pertenece al grupo 2 de la tabla periódica. Los **me…
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¿qué característica de los átomos de neón y argón indica que los elemen…
D. el número de electrones en la capa exterior de cada átomo
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¿qué par de elementos tiene propiedades químicas similares? * na y rb l…
A. Na y Rb ### Second Question (¿Qué enunciado describe la relación entre los dos átomos?):
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must do | practice- types of chemical reactions which type of chemical …
To solve this, we analyze each reaction based on the definitions of chemical reaction types: ### Part (a) - Reaction: $\ce{KClO3 -> KCl + O2}$ - Analysis: A single compound breaks…
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¿qué propiedad es la misma para un átomo de argón y un átomo de criptón…
D. número de electrones de valencia
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must do | practice- types of chemical reactions which type of chemical …
### a. # Explanation: ## Step1: Identify reaction type A single compound (KClO₃) breaks into simpler substances (KCl and O₂). This fits decomposition (one[SSE onError error]
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¿qué grupo de elementos tiende a ganar electrones? * halógenos gases no…
A. halógenos ### Second Question:
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la gráfica muestra la curva de calentamiento del cloruro de aluminio. ¿…
3
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¿qué curva de calentamiento representa un halógeno que es líquido a una…
D. Halogen 4 Heating Curve (Opción 4)
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7) balance the equation by typing the numbers into each blank. type in …
4 $\text{KClO}_3 ightarrow$ 3 $\text{KClO}_4 +$ 1 $\text{KCl}$
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what type of reaction is the electrolysis of water? $2h_2o \ ightarrow …
1. decomposition reaction 2. carbon dioxide and water
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2) drag and drop the reactions with the equations. \\(\\ce{so3 + h2o ->…
- $\boldsymbol{SO_3 + H_2O ightarrow H_2SO_4}$: synthesis - $\boldsymbol{CaCO_3 ightarrow CaO + CO_2}$: decomposition - $\boldsymbol{Pb + FeSO_4 ightarrow PbSO_4 + Fe}$: single re…
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¿cómo el átomo de cloro se convierte en un ion cloruro? * al perder un …
### Primera pregunta: # Breves Explicaciones: El átomo de cloro (Cl) tiene 7 electrones en su nivel de valencia. Para alcanzar la configuración de gas noble (estabilidad), necesit…
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1) read and match the types of reactions with the descriptions when a s…
- when a substance reacts with oxygen to create energy in the form of heat or light → combustion reaction - when one substance breaks down into two or more substances → decomposit…
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5) choose the best answer. according to le chatelier’s principle, what …
5. The reaction will shift toward the reactants. 6. concentration of reactant(s) or products