化学
化学反应、化学计量、分子结构与元素性质。
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question 12 5 pts image of purple molecules options: element, compound,…
B. Compound ### Second Question (Question 12 Diagram)
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question 13 2 pts p₄ + 5 o₂ --> 2 p₂o₅ combustion reaction double repla…
D. Synthesis reaction (and also A. Combustion reaction, but synthesis is the core type here as it's combining substances; if considering combustion as a subset of synthesis for bu…
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question 10 2 k + 2 h₂o --> 2 koh + h₂ double replacement reaction synt…
Single replacement reaction ### Question 11
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question 10 5 pts image of molecular structures options: element, compo…
Element ### Second Diagram (Question 10)
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question 5 (1 point) retake question if 250ml of 0.200 mol/l solution o…
0.150
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question 7 2 pts h₂co₃ --> h₂o + co₂ decomposition reaction combustion …
A. Decomposition reaction ### Question 8
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question 8 5 pts options: element, compound, mixture of elements, mixtu…
B. Compound ### Second Part (Question 8 Diagram)
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question 4 2 naclo₃ --> 2 nacl + 3 o₂ decomposition reaction synthesis …
A. Decomposition reaction ### Question 5
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question 5 5 pts image of green spheres ○ element ○ compound ○ mixture …
A. Element ### Question 6
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question 1 c₃h₈ + 5 o₂ --> 3 co₂ + 4 h₂o decomposition reaction single …
Combustion reaction ### Question 2
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greenhouse gas major greenhouses gases have what is known as a greenhou…
CFCs
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question 4 5 pts element compound mixture of elements mixture of compou…
Mixture of Compounds (the option labeled "Mixture of Compounds")
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depleting chemicals ions pose a threat to the ozone layer when chlorine…
A. the long lifespan of the chemicals
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10. in writing lewis structures for molecules, what do we mean by the o…
The octet rule means that atoms (except H, He) strive to have 8 valence electrons (like noble gases) when forming bonds. Attaining an octet is important as noble gas - like electr…
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question 7 (1 point) retake question when 0.25 mg_(s) is added to 250ml…
If we assume the mass of Mg is $0.25\space mol$ (correcting the unit error), the concentration of $\ce{Mg^{2+}}$ is $\boldsymbol{1.00\space mol/L}$ (or if the mass is $0.25\space …
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question 3 5 pts element compound mixture of elements mixture of compou…
B. Compound
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describe the conditions necessary for sublimation to occur.
Sublimation occurs when: 1. The atmospheric pressure is below the substance’s triple - point pressure (e.g., dry ice sublimes at 1 atm as its triple - point pressure is higher). 2…
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question 6 (1 point) retake question when 0.25 mg(s) is added to 250ml …
$\boxed{0.50}$ (or 0.51, depending on precision) g $\ce{H_{2}}$
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viruses, bacteria, and parasitic worms found in water that cause diseas…
B. infectious agents
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part a 0.665 mol magnesium fluoride m$_{\\text{mgf}_2}$ = \\boxed{} g s…
\(41.4\) (or more precise \(41.43\))
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when are parts per million and parts per billion used as measurements? …
when measuring concentrations that are smaller than 1% (the third option)
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automobile airbags inflate following a serious impact. the impact trigg…
\(24.0\)
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which impurity found in coal can lead to acid rain in the atmosphere? o…
B. sulfur
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what is the pressure of a 1.0 l flask containing 0.60 g of he at 25°c? …
3.7 atm (the option: 3.7 atm)
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how many moles of gas were added to a balloon that started with 2.3 mol…
9.5 (the option with 9.5)
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what is the primary goal of integrated pest management (ipm)? to contro…
D. to reduce pest damage to an acceptable level
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part a what is the pressure of 760 mm hg when expressed in units of pa?…
The correct option is the one with "101,325 Pa" (the third option in the list of radio buttons).
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part a which of the following correctly defines the principles of kinet…
The option "There are no attractions between particles."
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what is the percent yield of cus for the following reaction given that …
42.1% (corresponding to the option "42.1%")
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part a a 24.0 g sample of nitrogen gas reacts with an excess of hydroge…
13.2% (Option: 13.2%)
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part a how many moles of lithium nitrate are theoretically produced if …
6.8 (corresponding to the option "6.8")
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how many moles of nh₃ can be produced by the reaction of 2.00 g of n₂ w…
0.143
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part a how many grams of aluminum oxide are produced according to the r…
18.9
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part a for the reaction, calculate how many grams of the product form w…
\( 3.6 \)
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part a for the reaction, calculate how many grams of the product form w…
$\boxed{3.6}$
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part a for the reaction, calculate how many grams of the product form w…
\(5.0\space g\)
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part a for the reaction, calculate how many grams of the product form w…
\( 3.9 \)
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essential aks review unit 4 properties of matter name: period: what is …
The density of the metal cube is \(2.5\space g/cm^3\).
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how many moles of sodium metal are needed to make 3.6 moles of sodium c…
3.6 (the option: 3.6)
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how many moles of chlorine gas are needed to make 0.6 moles of sodium c…
0.3 (corresponding to the option "0 3" in the given choices)
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identify the double displacement reactions among the following: 1. $kcl…
All of 1, 2, and 3
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what type of reaction is the generic equation ab → a + b? ○ synthesis/c…
B. decomposition
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fill in the blank with the letter next to the path you took. fill in bl…
E. \( \text{g}\ \text{C}_3\text{H}_6 \to \text{mol}\ \text{C}_3\text{H}_6 \to \text{mol}\ \text{H}_2 \to \text{L}\ \text{H}_2 \)
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which reactions are redox reactions? check all that apply. 4k(s) + o₂(g…
A. \(4\text{K}(s) + \text{O}_2(g) ightarrow 2\text{K}_2\text{O}(s)\), B. \(\text{Al}(s) + 3\text{Ag}^+(aq) ightarrow \text{Al}^{3+}(aq) + 3\text{Ag}(s)\), C. \(\text{Mg}(s) + \tex…
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what are the products of the precipitation reaction between aqueous pot…
A. \(PbI_2\) and \(KNO_3\)
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given the rule that all compounds containing li⁺, na⁺, k⁺, nh₄⁺, no₃⁻, …
\( \text{CaCO}_3 \) (the option with \( \text{CaCO}_3 \))
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all of the following compounds are soluble in water except: nacl fecl₃ …
\( \text{PbCl}_2 \) (the option with \( \text{PbCl}_2 \))
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list two examples of aqueous solutions. check all that apply □ h₂o(l) □…
B. \( \text{Co(NO}_3\text{)}_2(\text{aq}) \), C. \( \text{NaBr}(\text{aq}) \)
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list two examples of aqueous solutions. check all that apply h₂o(l) co(…
B. \( \ce{Co(NO3)2(aq)} \), C. \( \ce{NaBr(aq)} \)
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what is an aqueous solution? ○ an aqueous solution is a dispersoid solu…
C. An aqueous solution is a homogeneous mixture of a substance with water.
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sodium metal reacts with water to form aqueous sodium hydroxide and hyd…
\( 2\text{Na} + 2\text{H}_2\text{O} ightarrow 2\text{NaOH}(aq) + \text{H}_2(g) \) (the first option in the list)
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sodium metal reacts with water to form aqueous sodium hydroxide and hyd…
A. $2\ce{Na} + 2\ce{H2O} ightarrow 2\ce{NaOH(aq)} + \ce{H2(g)}$
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part a which of the following equations is not balanced properly? 4nh₃ …
\(4NH_3 + 14O_2 \to 4NO_2 + 6H_2O\) (the first equation is not balanced properly)
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part a when the equation __no₂ + __h₂o + __o₂ → __hno₃ is balanced, the…
4 (corresponding to the option "4")
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read through the question below and determine the known substance and t…
A. Known is the molecular hydrogen. Unknown is the hydrogen chloride.
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what are the main indications that a chemical reaction has occurred? ch…
A. emission of light, B. a color change, D. emission of (or absorption of) heat, E. formation of a solid, F. formation of a gas
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a 15.5 gram sample of diphosphorous pentoxide contains how many grams o…
6.76 (corresponding to the first option: 6.76)
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how many moles of h are present in 12 moles of ch₄? ○ 48 moles h ○ 4 mo…
48 moles H
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61.4 g n₂ express your answer using three significant figures. n = mole…
\(1.32\times10^{24}\)
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part a 4.6 g h₂o express your answer using two significant figures. n =…
\( 1.5 \times 10^{23} \) (or \( 1.6 \times 10^{23} \) if there was a miscalculation, but based on the steps, it's \( 1.5 \times 10^{23} \)) Wait, no, let's check again. 4.6 is two…
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search the bold text headers for \low-acid food\. what is the definitio…
A. Food with pH above 4.6.
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calculate the molar mass of calcium nitrate. 136.03 g/mol 164.10 g/mol …
164.10 g/mol (corresponding to the option "164.10 g/mol")
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what is the mass of $1.56 \\times 10^{21}$ atoms of magnesium in grams?…
0.0630 (corresponding to the option "0.0630")
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how many moles of bromine gas are in 37.7 grams? 3.01 × 10³ 0.472 0.236…
0.236 (the option with "0.236")
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part a how many moles of cu are in 1.48 × 10²⁵ cu atoms? ○ 6.022 × 10²³…
24.6 (the option with "24.6")
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4. observe: click reset. set the water temperature to 20 °c and the ice…
B. molecules collide with the solid
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ammonia gas decomposes according to the equation: $2nh_3(g) \ ightarrow…
45.0 L (corresponding to the option with 45.0 L)
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a volume of 18.0 l contains a mixture of 0.250 mole n₂, 0.250 mole o₂, …
1.21 g
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part a a mixture of he, ar, and xe has a total pressure of 2.30 atm. wh…
\( 1.75 \, \text{atm} \)
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part c a240: l kiln is used for vitrifying ceramics. it is currently op…
\( 2.29 \, \text{mol} \)
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fill in the blank question a process in which atomic orbitals mix and f…
hybridization
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part b a 20.0 l gas cylinder is filled with 8.00 moles of gas. the tank…
\( 9.66\,\text{atm} \)
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a balloon is floating around outside your window. the temperature outsi…
\( 91.2 \, \text{L} \) (or \( 91.1 \, \text{L} \) depending on rounding, but precise calculation gives ~91.2 L)
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fill in the blank question the electron pairs in a molecule repel one a…
minimizes
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a balloon is floating around outside your window. the temperature outsi…
The pressure in the tank is \( \boxed{9.66 \, \text{atm}} \)
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1 of 12 concepts completed multiple choice question which molecular sha…
D. trigonal planar (assuming the options are labeled A - D with D as trigonal planar; if the original options' labels differ, adjust to the correct label with "trigonal planar")
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multiple choice question which is the model used to determine molecular…
C. VSEPR model
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part b a sample of gas in a cylinder as in the example in part a has an…
\(0.325\space mol\)
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why are shared bonding orbitals pushed together by unshared pairs of el…
D. Unshared pairs of electrons occupy a slightly larger orbital than shared electrons.
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true or false question true or false: bond angles predicted by vsepr ar…
False
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multiple choice question the vsepr model says that the shape of a molec…
A. minimize interactions between electron pairs because they repel one another
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fill in the blank question the model used to determine molecular shape …
VSEPR
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charless law states that the volume of a gas is directly related to the…
The value of \(T_2\) is \(\boldsymbol{363^\circ\text{C}}\) (or \(636\,\text{K}\), but in Celsius as required, approximately \(363^\circ\text{C}\))
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for a certain amount of gas at constant temperature, the pressure and v…
The new pressure \( P_2 \) is \(\boxed{241}\) torr.
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gases are different from solids and liquids. in a sample of gas, the mo…
\(2.73\times 10^{6}\) (or more precisely, after exact calculation: \(3.64\times10^{8} \times \frac{760}{101325} = \frac{3.64\times760\times10^{8}}{101325}=\frac{2766.4\times10^{8}…
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gases are different from solids and liquids. in a sample of gas, the mo…
\(1.94\) (rounded to two decimal places, or \(1.939\) for more precision)
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consider the following reaction between sulfur trioxide and water: so₃(…
\(88.2\%\)
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post-test all of the following are advantages of using aluminum except:…
C. Easy to repair
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consider the following reaction between sulfur trioxide and water. so₃(…
60.9
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consider the following reaction between sulfur trioxide and water. so₃(…
\( H_2O \)
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6) 7 n nitrogen 14.00 protons: ______ neutrons: ______ electrons: _____…
Protons: 7 Neutrons: 7 Electrons: 7 Valence Electrons: 5
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missed this? watch kcv: limiting reactant, theoretical yield, and perce…
$\approx 61.4\ \text{g}$
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missed this? watch kcv: limiting reactant, theoretical yield, and perce…
HCl
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missed this? watch kcv: limiting react, theoretical yield, and percent …
\( 77.0\% \) (or rounded as needed, e.g., 77% or 77.0)
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missed this? watch kcv: limiting reactant, theoretical yield, and perce…
Mg
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part d for the reaction, calculate how many grams of the product form w…
\( 3.4 \)
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part b for the reaction, calculate how many grams of the product form w…
\( \boxed{4.6} \) (grams, for Part B) --- ### Part C: Reaction \( 2\text{Mg} + \text{O}_2 ightarrow 2\text{MgO} \) ## Step1: Moles of Mg Molar mass of \( \text{Mg} = 24.31 \, \tex…
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part a for the reaction, calculate how many grams of the product form w…
\( 4.3 \)
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4) 4 be beryllium 9.01 protons: ______ neutrons: ______ electrons: ____…
### Para Beryllium (Be): - Protons: 4 - Neutrons: 5 - Electrons: 4 - Valence Electrons: 2 ### Para Fluorine (F): - Protons: 9 - Neutrons: 10 (o \( 18.99 - 9 \approx 10 \)) - Elect…
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missed this? watch kcv: reaction stoichiometry, iwe: mass-to-mass conve…
\( 11.1 \, \text{g} \) (rounded to three significant figures)