化学
化学反应、化学计量、分子结构与元素性质。
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determine the molar mass of ch₃oh. provide an answer to two decimal pla…
\(32.05\space g/mol\)
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determine the molar mass of nano3. provide an answer to two decimal pla…
\(85.00\space g/mol\)
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determine the molar mass of ca(oh)2. provide an answer to two decimal p…
\(74.10\ \text{g/mol}\)
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how many oxygen atoms are in 30 molecules of dinitrogen tetroxide, n₂o₄?
120
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how many carbon atoms are in 23 molecules of benzene, c₆h₆?
138
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how many o atoms are in one formula unit of mg(no3)2?
6 O atoms
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how many n atoms are in one formula unit of (nh₄)₂so₄?
\(2\)
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5. compare and contrast elements and compounds. list at least three dif…
1. Elements are pure substances with one - type atoms; compounds are formed by combining elements. 2. Elements can't be chemically broken down; compounds can be decomposed. 3. Ele…
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particles in a gas move quickly, are farther apart, and the attractive …
Weak (or negligible)
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the state of matter with a definite shape and a definite volume is a __…
solid
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the state of matter that has a definite volume but no definite shape is…
liquid
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4. label the following as e -element, c-compound, heterogeneous mixture…
Fe - E, \(N_{2}O_{5}\) - C, Chocolate chip ice cream - HM, \(NaHCO_{3}\) - C, Tomato sauce - HM, Gasoline - S, Salad bar - HM, \(N_{2}\) - E
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if 87 g of nitrogen monoxide, no, is produced from the reaction of 150 …
77 %
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what is the limiting reactant and how much cr is produced when 24.0 g o…
\(Cr_2O_3\) is the limiting reactant and \(27.4\space g\) of \(Cr\) is produced. So the answer is: \(Cr_2O_3\) is the limiting reactant and \(27.4\space g\) of \(Cr\) is produced.
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what is the net ionic equation for the reaction below? pb(no₃)₂(aq) + n…
$\mathrm{Pb^{2+}(aq)+CrO_4^{2 - }(aq)\to PbCrO_4(s)}$
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what is the closest bond angle around the central atom? 180° 120° 90° 1…
\(109.5^{\circ}\)
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what is the vsepr geometry of the particle? trigonal planar tetrahedral…
bent
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what is the closest bond angle around the central atom?
\(109.5^{\circ}\)
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what is the vsepr geometry of the particle?
tetrahedral
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what is the closest bond angle around the central atom? :f--be--f: 180°…
\( 180^{\circ}\)
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which of the following is a strong electrolyte in aqueous solution? amm…
potassium phosphate, \(K_3PO_4\)
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what is the stoichiometric coefficient for o₂ when the following equati…
\(19\)
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what is the vsepr geometry of the molecule? :f--be--f: tetrahedral bent…
linear
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what is the closest bond angle around the central atom? 109.5° 120° 180…
109.5°
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what is the vsepr geometry of the particle?
tetrahedral
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what is the closest bond angle around the central atom?
109.5°
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what is the vsepr geometry of the particle?
trigonal pyramidal
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what is the bond angle of this linear molecule? h - c≡n:
\(180^{\circ}\)
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the molecule has 2 bonding domains. what is the vsepr geometry of this …
linear
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how many domains does this molecule have around the central atom? h - c…
2 bonding
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what is the bond angle around the indicated trigonal pyramidal atom? <1…
\(< 109.5^{\circ}\)
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the indicated atom has 3 bonding and 1 lone pair domain. what is the vs…
trigonal pyramidal
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how many domains are around the indicated atom? 2 bonding/1 lone pair 3…
3 bonding / 1 lone pair
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what is the bond angle of this tetrahedral molecule? 180° 120° 90° 109.…
\(109.5^{\circ}\)
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the molecule has 4 bonding domains. what is the vsepr geometry of this …
tetrahedral
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how many domains does this molecule have?
4 bonding
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which of the following is a precipitation reaction? 2 lioh(aq) + h₂so₄(…
\(NaCl(aq)+AgNO_{3}(aq)\to AgCl(s)+NaNO_{3}(aq)\)
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complete the vsepr table. geometry domains angle ? 180° 3 bonding bent …
| Geometry | Domains | Angle | |--|--|--| | linear | 2 | \(180^{\circ}\) | | trigonal planar | 3 bonding | \(120^{\circ}\) | | bent | 2 bonding / 1 lone pair | \(120^{\circ}\) | |…
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if 30.7 g of iron(iii) oxide is obtained from the reaction of 85.3 g of…
54.0 %
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ammonia reacts with diatomic oxygen to form nitric oxide and water vapo…
1.88 mol
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calculate the mass of ( p_{4}o_{10}(s) ) formed when 225 g of ( ph_{3} …
470 g
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when the following equation is balanced using the smallest set of whole…
11
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which of these causes the atmosphere to change? ncreased inorganic matt…
increased buildup of greenhouse gases
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which contributing factors cause the thermosphere to be warmer than the…
Gases are more dense in the thermosphere and absorb energy easily.
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bread reach performance task student flour contains 0.05% glucose. the …
Pour la recette d'Amy : \(0.208\space mol\) Pour la recette d'Eli : \(0.333\space mol\)
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which variables have a direct effect on movement in chromatography? che…
Solubility of pigment, Size of pigment
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directions: name the following ionic compounds. 11. ba(so₄) 12. mgcl₂ 1…
11. Barium sulfate 12. Magnesium chloride 13. Calcium carbonate 14. Beryllium phosphide 15. Aluminum nitrate 16. Copper(I) nitrate 17. Lead(IV) nitride 18. Chromium(III) chloride …
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5 imagine that you used a magic marker to take notes in your biology cl…
- The marker ink was water soluble. - This was an unintentional chromatography experiment.
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question 52 2 pts what is one reason why the amygdala become more sensi…
All of the above
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4. why can bugs and leaves float on top of water? * mark only one oval.…
4. surface tension 5. 2 hydrogens and one oxygen
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3. which of the following is a property of water? * mark only one oval.…
all of the above
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multiple - choice question why is carbon is important in industry and h…
To make cars run (fuel), To provide energy for our homes, schools and businesses.
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question 8 which of the following would form a covalent bond? a p and i…
A. \(P\) and \(I\)
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how does rb bond with other elements? (1 point) ○ rb gains an electron.…
Rb loses an electron.
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which of the following combination of elements is the most reactive? (1…
K and Br
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which feature is unique to group 18 nonmetals? (1 point) o they have mo…
They are very nonreactive.
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how do nonmetals tend to form bonds? (1 point) o by gaining protons o b…
by gaining electrons
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why does the reactivity of metals increase from right to left on the pe…
Metals on the right have more protons, causing valence electrons to be held more strongly.
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when drawing the lewis structure for so4 2-, there are ___ equivalent r…
A. 3
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rewrite the sentence correctly. particles is aranged close together in …
- First sentence correction: Particles are arranged close together in solids, and far apart in gases. - Second sentence: Circle "higher", underline "greatest".
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1. what is shortening? * a. a type of margarine made from dairy cream b…
1. B. A semisolid fat made from hydrogenated vegetable oil 2. C. Hydrogenation
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match the state of matter with the correct name of the water. drag & dr…
Gas - Water Vapor Liquid - Liquid Water Solid - Ice
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question 20 which part of daltons atomic theory is incorrect? a atoms a…
A. Atoms are not changed in a chemical reaction
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2. which electron - dot formula represents calcium oxide? o $:\\ddot{\\…
\(Ca^{2+}[\colon\ddot{O}\colon]^{2 - }\) (the third option)
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1. which electron dot formula correctly represents the hydrocarbon acet…
\(H:C:::C:H\) (the fourth option)
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11 what causes gases to easily mix with each other compared to solids o…
B. Gases have particles that move independently and rapidly
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10 what determines whether a phase change is endothermic or exothermic?…
D. Whether energy is absorbed or released during the change
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9 describe the particle arrangement in liquids compared to solids and g…
B. Particles are close together but can slide past each other
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what is the common factor between melting and vaporization? a both are …
A. Both are endothermic processes
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4. caffeine, a stimulant in coffee and tea has a molar mass of 194.19 g…
C. \(C_8H_{10}N_4O_2\)
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7 when does sublimation of a substance typically occur? a only when the…
D. By gaining enough energy to skip the liquid phase
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6 why do particles in a liquid have more freedom of movement than in a …
C. Intermolecular forces are weaker in liquids than in solids
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what are some characteristics of cations and anions? move the answers t…
- "formed by losing electrons" and "positively charged" go to "cation". - "negatively charged" (assuming the full term is "negatively charged" which is for anion as anions gain el…
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3 which of the following statements accurately describes a characterist…
D. Phase changes involve energy transfer affecting particle motion
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2 what defines the boiling process in terms of particle energy? a parti…
A. Particles gain enough energy to overcome atmospheric pressure
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3. which lewis electron - dot diagram is correct for a s²⁻ ion?
\([:\ddot{S}:]^{2 - }\) (the fourth option)
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2. the electron - dot symbol below represents an ion of element x. whic…
I
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1. which lewis dot structure correctly represents an aluminum atom in t…
The Lewis dot structure with 3 non - paired dots around "Al" (the first option if the first option has 3 non - paired dots as per the correct valence electron count) is the correc…
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complete the following electron dot structure
The correct option is the one with two lines (a double bond) between the two oxygen atoms.
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unit test 2 - electronic structure and chem complete the following elec…
The correct electron - dot structure is the one with a double bond (\(\ce{:\overset{..}{O}=\overset{..}{O}:}\)), so the answer is the option with the double - bond (the middle opt…
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in a molecule of nitrogen, the two nitrogen atoms are joined by a tripl…
6
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which two elements will form ionic bonds with the structure below?
Al and S
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which option is true based on the sentence below? anais wattersons base…
She has only one baseball coach.
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6. balance the following neutralization reactions: a) hbr + koh → kbr +…
a) \(1\) \(HBr+1\) \(KOH ightarrow1\) \(KBr + 1\) \(H_{2}O\) b) \(3\) \(HF+1\) \(Fe(OH)_{3} ightarrow1\) \(FeF_{3}+3\) \(H_{2}O\) c) \(2\) \(HCl + 1\) \(Ca(OH)_{2} ightarrow1\) \(…
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the process by which a gas changes directly into a solid is called a. e…
D. Deposition
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level 5 q2 at what temperature is the boiling point of water? a. 100°c …
A. $100^{\circ}C$ ($212^{\circ}F$)
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the process by which a solid changes directly into a gas is called a. e…
C. Sublimation
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the electron configurations of two unknown atoms are shown. the reactio…
Similar precautions (or more stringent ones) need to be followed. Potassium is more reactive than Atom X (likely sodium). The reaction between potassium and chlorine is more exoth…
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what causes the colors in a firework display?* your answer
The colors in a firework display are caused by the emission of light when electrons in metal atoms (from metal salts in the fireworks) return to lower - energy levels after being …
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which of the following statements about the properties of elements rela…
D. An atomic emission spectrum shows the pattern formed when light emitted by an element is separated into its different component wavelengths. E. An atomic emission spectrum occu…
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how many valence electrons does oxygen have atoms have? 1s²2s²2p⁴ 2 6 8…
6
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what causes the colors in a firework display?*your answerwhat is the at…
4
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level 4 q2 ______ dont have a definite shape, instead they fill up any …
A. Gases
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during a classroom experiment, a burning magnesium ribbon was dropped i…
Ca, it belongs to Group 2
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the _________________ is the electron - containing main energy level wi…
highest occupied level
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what is the mass number of oxygen - 16? 12 8 16 24
16
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a single chlorine atom weighs 35.45 g. periodic table of elements chemi…
false
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how many valence electrons does calcium have?
2
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how many valence electrons does this atom have? ar4s²3d¹⁰4p³ 17 8 7 10
7
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the electrons available to be lost, gained, or shared in the formation …
valence Electrons