Química
Reacciones químicas, estequiometría, estructuras moleculares y propiedades.
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iron, an element with the chemical symbol fe, is an important element. …
B. The electrons of iron have probable locations in a region of space around the nucleus.
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when electrons are removed from the outermost shell of a calcium atom, …
D. a cation that has a smaller radius than the atom. (Note: Assuming the options are labeled A - D in the order given, with the last option being the correct one.)
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which element is the most reactive? ○ sodium ○ nickel ○ carbon ○ oxygen
A. sodium
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how many valence electrons does aluminum (al) have available for bondin…
3 (corresponding to the option "3")
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which of the following symbols would be included in the noble gas notat…
B. Kr
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which physical method can be used for obtaining a sample of salt from a…
A. boiling
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volume and density worksheet name: date: class period: instructions: 1.…
56 ### Problem 2
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what is the predicted order of first ionization energies from highest t…
Li > Na > K > Rb
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part 1: introduction to polyatomic ions (table partner - 7 min. group p…
No. Oxygen needs an octet (8 valence electrons) and has 6 (or 7 in the shared case), while Hydrogen needs a duet (2 valence electrons) and has 1 (or 2 in the shared case, but O is…
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drag each tile to the correct box. complete each analogy with the appro…
Wood is to fire as food is to subsistence. Grinning is to cheerful as teetering is to precarious. Conniving is to scheming as terrible is to abysmal. Mournful is to sad as glutton…
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16. the fuel tank of an airplane has a device that measures the fuels t…
b. The molecules started moving slower.
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balance the chemical equation using the smallest possible whole number …
$2\text{HI}_{(g)} ightarrow \text{H}_{2(g)} + \text{I}_{2(g)}$
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balance the chemical equation using the smallest possible whole number …
$\boldsymbol{8}$ Fe$_{(s)}$ + $\boldsymbol{1}$ S$_{8(s)}$ $ ightarrow$ $\boldsymbol{8}$ FeS$_{(s)}$
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balance the chemical equation using the smallest possible whole number …
$\boldsymbol{8}$ Fe$_{(s)}$ + $\boldsymbol{1}$ S$_{8(s)}$ $ ightarrow$ $\boldsymbol{8}$ FeS$_{(s)}$
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balance the chemical equation using the smallest possible whole number …
$\boldsymbol{8}$ Fe$_{(s)}$ + $\boldsymbol{1}$ S$_{8(s)}$ $ ightarrow$ $\boldsymbol{8}$ FeS$_{(s)}$
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balance the chemical equation using the smallest possible whole number …
(blank) $\text{CO}_{(g)} +$ (blank) $\text{Cl}_{2\ (g)} ightarrow$ (blank) $\text{COCl}_{2\ (g)}$
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balance the chemical equation using the smallest possible whole number …
$\boldsymbol{CO_{(g)} + Cl_{2(g)} \longrightarrow COCl_{2(g)}}$ (los coeficientes son 1, 1 y 1, por lo que se dejan los espacios en blanco)
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balance the chemical equation using the smallest possible whole number …
$\text{Na}_2\text{S}_{(aq)} + \text{FeCl}_{2(aq)} \longrightarrow 2\text{NaCl}_{(aq)} + \text{FeS}_{(s)}$ (Coeficientes en orden: 1 (vacío), 1 (vacío), 2, 1 (vacío))
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balance the chemical equation using the smallest possible whole number …
First blank (B): 2 Second blank (H₂): 3 Third blank (B₂H₆): (blank, or 1) Balanced equation: $\boldsymbol{2\ \text{B}_{(s)} + 3\ \text{H}_{2(g)} ightarrow \text{B}_2\text{H}_{6(g)…
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what do these two changes have in common? snowflakes forming in a cloud…
- Both conserve mass. - Both are only physical changes.
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what do these two changes have in common? rust forming on a metal gate …
- Both are chemical changes.
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what do these two changes have in common? water boiling on a stove your…
- Both are only physical changes.
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what do these two changes have in common? newly poured concrete becomin…
- Both conserve mass. - Both are changes of state.
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8. which graph best shows the general relationship between the temperat…
a. Graph 1
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what happens to the molecules in a gas as it is cooled inside a jar? a.…
A. The molecules move more slowly.
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chemistry was my favorite subject, but my teacher was extremely monoton…
D. tedious
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4. lily is doing a science experiment with a substance in a sealed jar.…
b. faster, and the substance will be a gas.
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tableau des résultats : | substances | solute (masse, g ± 0.01) | tempé…
### Résultats corrigés : 1. **NaOH** - $Q_{eau}=1927,4\ \text{J}$ - $\Delta H_{rx}=-1,93\ \text{kJ}$ - $n=0,0485\ \text{mol}$ - $\Delta H_{mol}\approx-39,7\ \frac{\text{kJ}}{\text…
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phase changes and chemical reactions worksheet part 1: defining the bas…
1. False 2. A phase change is a physical change that only alters the state of matter without forming new substances, while a chemical reaction breaks and forms chemical bonds to c…
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question 1 (1 point) which concept describes the movement of large sect…
d. Plate tectonics ### Question 2
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unit 7 - moles calculate the number of moles in each of the following m…
Approximately $28.1\ \text{g}$ (or $28.05\ \text{g}$) ### Question 7
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practice: moles to mass & mass to moles calculate the mass of each of t…
Approximately \( 2.38 \, \text{mol} \) (or \( \frac{64.1}{26.98} \approx 2.376 \), rounded as needed) ### Problem 17:
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9. zinc (zn) is used to form a corrosion-inhibiting surface on galvaniz…
A. \( 1.51 \times 10^{24} \) atoms
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8. how many molecules are in 3.50 mol of sucrose? (0.5 points) * 3.11 x…
2.11 x 10²⁴ molecules (the option with this value)
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7. challenge: calculate the number of oxygen atoms in 5.00 mol of oxyge…
6.022 x 10²⁴ atoms (the option with this value)
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6. arrange these three samples from smallest to largest in terms of num…
\(6.78 \times 10^{22}\) molecules glucose, \(2.14 \times 10^{24}\) atoms Fe, \(1.25 \times 10^{25}\) atoms Zn
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5. how is a mole defined? (0.5 points) * the number of ions in 20 g of …
D. The number of carbon atoms in exactly 12 g of pure carbon - 12
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21. draw the orbital diagrams and electron configurations of the follow…
a. Mg: Electron configuration: $\boldsymbol{1s^22s^22p^63s^2}$; Orbital diagram: $1s: \uparrow\downarrow,\ 2s: \uparrow\downarrow,\ 2p: \uparrow\downarrow\ \uparrow\downarrow\ \up…
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3. calculate the number of molecules in 11.5 mol of water. (0.5 points)…
D. \( 6.93 \times 10^{24} \) molecules
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2. the ____ is the si base unit used to measure the amount of a substan…
B. Mole
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1. silver nitrate is used to make several different silver halides used…
B. \( 1.96 \times 10^{24} \) formula units
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question 7 (2 points) what element is always present in an organic comp…
4) Carbon
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4. copper is an element that is required in very small concentrations i…
\(0.030\space ppm\)
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convert 60.5 g of oxygen (o₂) to moles. round your answer to 2 places a…
2.49
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of 0.518 moles of platinum (pt)? round your answer to three numbers. ty…
101
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13 what is the mass of .8 mol of cacl₂? (nearest whole number; no units)
111
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10 a sample contains 5.5 × 10²⁴ atoms of cadmium. what is the mass of t…
The mass of the sample of calcium is approximately \(\boldsymbol{366\space g}\) (or if we consider more precise steps, it can be calculated as follows: \(n=\frac{5.5\times 10^{24}…
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3 how many grams in 5.5 mol of copper? (nearest whole number; no units)
350
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how many grams in 5 moles of co₂? (nearest whole number; no units)
220
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question 43 of 49 identify the optimum c-c-c bond angle for each of the…
1. Topmost (alkyne $\text{CH}_3\text{C}\equiv$): $180^\circ$ 2. Second top (middle alkyne $\equiv\text{C}-$): $180^\circ$ 3. Third top ($\equiv\text{C-CH}_2-$): $109.5^\circ$ 4. C…
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a quatrain is a stanza consisting of ___ lines. * 2 3 4 5 what is a ref…
1. 4 2. A line or group of lines that repeats throughout a poem to add emphasis
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a free verse poem ______. * - has no regular rhyme or meter - always te…
1. Has no regular rhyme or meter 2. A grouping of lines in a poem 3. A single row of words in a poem
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a couplet is a stanza consisting of ___ lines. * 2 3 4 5 the meter of a…
1. 2 2. The pattern of stressed and unstressed syllables 3. The pattern of similar sounding sounds at the end of each line, alphabetical (A B C)
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15 fill in the blank 5 points the type your answer... is the subatomic …
proton
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unit 2 - types of matter and the atom 1. explain what each of the follo…
An element is a pure substance composed of only one type of atom (particles: single atoms or molecules of the same atom). Bonding: metallic (for metals), covalent (for diatomic el…
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8. aqueous sodium phosphate reacts with aqueous calcium chloride to for…
### Question 8: Reactants: Aqueous sodium phosphate ($\text{Na}_3\text{PO}_4$), aqueous calcium chloride ($\text{CaCl}_2$) Products: Solid calcium phosphate ($\text{Ca}_3(\text{PO…
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8.____ al + ____ fe₂o₃ → ____ al₂o₃ + ____ fe 9.____ na + ____ i₂ → ___…
8. $2\text{Al} + 1\text{Fe}_2\text{O}_3 ightarrow 1\text{Al}_2\text{O}_3 + 2\text{Fe}$ 9. $2\text{Na} + 1\text{I}_2 ightarrow 2\text{NaI}$ 10. $2\text{Mg} + 1\text{O}_2 ightarrow …
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physics & chemistry worksheet: light and the atom name: date: period: p…
1. Amplitude - B. The height of a wave from the origin to the crest. 2. Atomic Emission Spectrum - A. The specific frequencies of light emitted by an element. 3. Electromagnetic R…
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balancing equations worksheet name balance the following equations and …
### Problem 2: Balancing \( \boldsymbol{\text{Fe} + \text{HCl} ightarrow \text{FeCl}_3 + \text{H}_2} \) # Explanation: ## Step 1: Balance Fe atoms On the left, we have 1 Fe atom. …
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8.\\underline{\\quad\\quad} al + \\underline{\\quad\\quad} fe₂o₃ → \\un…
2, 1, 1, 2 ### Problem 9:
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question 11 of 49 draw the lewis structure of h₂so₄ with minimized form…
The Lewis structure has a central sulfur atom bonded to two oxygen atoms via double bonds (each double-bonded O has 2 lone electron pairs) and two oxygen atoms via single bonds. E…
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what process is responsible for the sun’s production of energy? ○ nucle…
1. Nuclear fusion of hydrogen into helium 2. The amount of helium will increase, and the amount of hydrogen will decrease over time.
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question 10 of 40 consider these structures, methylene ethyl radical fo…
### First question (formal charge 0 on electron-bearing C): both ### Second question (net charge 0): both
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add lone pairs to compound a.
The final structure has each sulfur atom with 2 lone pairs: ``` H | H - C - S::S::C - H | | H H ``` (Each `::` represents 2 lone pair electrons, so each S has 4 non-bonding electr…
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question 33 of 49 identify the major and minor resonance contributor(s)…
Identify the major contributor(s): A. $\ce{H-C(=O)-O^{-}}$ (structure A), B. $\ce{H-C(=O^{-})-O}$ (structure B) Identify the minor contributor(s): C. $\ce{H-C^{+}(-O^{-})-O^{-}}$ …
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organic chemistry loudon roberts & company publishers presented by macm…
O−N=O angle: 120 N−C−H angle: 109.5
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organic chemistry loudon roberts & company publishers presented by macm…
H-C-H angle: $120$ ° C=C=C angle: $180$ °
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question 47 of 49 organic chemistry loudon roberts & company publishers…
$^+CH_3$: $120^\circ$ $SiCl_4$: $109.5^\circ$
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predict the approximate bond angle in the molecule. o(=o^+)-o^- (with l…
Approximately $117^\circ$ (or slightly less than $120^\circ$)
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the image shows a chemical structure of a molecule with a central o ato…
$\boldsymbol{sp^3}$
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indicate the hybridization of the central atom in each molecule shown. …
First molecule (CO₂): sp Second molecule (BeF₂): sp
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question 37 of 49 determine the hybridization of the central atom for e…
For $\text{AlCl}_4^-$: $\boldsymbol{sp^3}$ For $\text{S=C=S}$: $\boldsymbol{sp}$
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several alkene compounds are shown. indicate if each compound can exist…
1. Can $\text{CH}_3\text{CH=CHCH}_3$ exist as stereoisomers? yes 2. Can $\text{CH}_3\text{CH=CBrCH}_2\text{CH}_3$ exist as stereoisomers? yes 3. Can the drawn branched alkene exis…
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question 40 of 49 a 3d representation of a cyclohexane (c₆h₁₂) molecule…
geometry: tetrahedral What is the hybridization of each carbon atom? $\boldsymbol{sp^3}$
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assessment questions 1. which unit is used to measure mass in the metri…
1. Gram 2. 506.4 g
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question 42 of 49 match the molecular geometry (from the answer bank) t…
1. Top $\text{CH}_2$: trigonal planar 2. Middle $\text{CH}$: trigonal planar 3. First $\text{CH}_2$ (below $\text{CH}$): tetrahedral 4. Second $\text{CH}_2$ (below first $\text{CH…
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predict the approximate molecular geometry of a formaldehyde molecule: …
trigonal planar
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predict the approximate molecular geometry around each carbon atom of a…
The carbon atom in $\text{CH}_3$ is: tetrahedral The nitrile carbon atom ($\text{C≡N}$) is: linear
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7. solid calcium carbonate breaks down into solid calcium oxide and car…
Reactants: Solid calcium carbonate ($\text{CaCO}_3$) Products: Solid calcium oxide ($\text{CaO}$), carbon dioxide gas ($\text{CO}_2$) Balanced equation: $\text{CaCO}_3(s) \xrighta…
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6. hydrogen gas reacts with nitrogen gas to form ammonia. reactants: pr…
Reactants: Nitrogen gas ($\text{N}_2$), Hydrogen gas ($\text{H}_2$) Products: Ammonia ($\text{NH}_3$) Balanced equation: $\text{N}_2 + 3\text{H}_2 ightarrow 2\text{NH}_3$
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4. a graduated cylinder contains 20.0 ml of water. after a rock is plac…
$14.0\ \text{cm}^3$ (or $14.0\ \text{mL}$)
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assessment questions 1. what volume is shown in the graduated cylinder …
1. 28 mL 2. 14 mL
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determine the formal charge on the nitrogen atom in each of the structu…
0 (corresponding to the option "0") ### For Structure B (NH₂ - attached to benzene ring)
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add lone pairs to compound b.
The structure with lone pairs added has: - 2 pairs of non-bonding electrons (lone pairs) on the double-bonded oxygen atom - 1 pair of non-bonding electrons (lone pair) on the nitr…
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add lone pairs to compound a.
The final structure has **two lone electron pairs on each sulfur atom**, resulting in the structure: ``` H H | | H - C - S - S - C - H | | H H (each S has two pairs of dots: :S-S:…
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a reporter is covering a protest at a local chemical plant suspected of…
Minimize harm because the protester might be affected by the interview. Seek truth from another source, because the protester made a statement about a major issue
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value: 3 ______ pest control mechanisms help reduce the carbon footprin…
b. Natural
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value: 3 identify the advantage(s) of organic farming. a. slows down gl…
f. Both A and C
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value: 3 due to ________ farming, more animals and plants can live in t…
c. Organic
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6. what family of organic compounds has historically been used in the c…
c) esters
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the water cycle includes living elements and non-living geological proc…
Biogeochemical cycle
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unit d final review have you mastered the concepts, applications, and s…
1. 0.500 mol of hydrogen gas 2a. 2.00 mol of elemental sulfur 2b. 0.100 mol of barium sulfide
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dissociation - the process by which chemical compounds break apart to f…
1. Reactions Between Ions: Reactions of dissolved ionic species in solution 2. Spectator Ions: Unchanged, non-participating ions in a reaction 3. Precipitate: Insoluble solid prod…
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46. describe the effect that increasing temperature has on the vapor pr…
Increasing the temperature of a liquid increases its vapor pressure. This is because higher temperature gives liquid molecules more kinetic energy, so more molecules can escape th…
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44. explain why increasing the temperature of a liquid increases its ra…
Increasing the temperature of a liquid increases the average kinetic energy of its molecules (via \( KE=\frac{3}{2}kT \), where \( k \) is Boltzmann’s constant and \( T \) is temp…
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34. change 1656 kpa to atm.
\(1656\ \text{kPa}\) is approximately \(16.34\ \text{atm}\)
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molecular masses calculate the molecular mass (in amu’s) for these mole…
To solve for the molecular mass of each compound, we use the atomic masses (in amu) of the constituent elements: \( \text{Na} = 22.99 \), \( \text{N} = 14.01 \), \( \text{O} = 16.…
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ii. atomic masses copy the masses of the following common elements. use…
| Element | Atomic Mass (amu) | |---------|-------------------| | H | 1.01 | | C | 12.01 | | S | 32.07 | | O | 16.00 | | Ca | 40.08 | | N | 14.01 | | Na | 22.99 | | Cl | 35.45 |
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10. a certain element has two naturally occurring isotopes with mass nu…
### Part (a) To determine the element, we first recall that the atomic mass of an element is a weighted average of its isotopes' masses. The formula for atomic mass ($A$) is $A = …
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lorganisation et le contenu du texte descriptif lecture annotée jadore …
La phrase est : "Prendre une photo réunissant des milliers de personnes représente tout un défi, n'est - ce pas? C'est l'exploit qu'a réussi à faire Arthur Mole, un photographe br…