化學
化學反應、化學計量、分子結構與元素性質。
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question 6 which of the following is correct about the balanced equatio…
C. Ethanol is a reactant.
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question 4 balance the equation by entering the correct numeric coeffic…
The coefficients for \(ZnS\), \(O_{2}\), \(ZnO\) and \(SO_{2}\) are \(2\), \(3\), \(2\) and \(2\) respectively.
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what is the percent yield if the theoretical mass was 37 g and the actu…
$51.57$
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balance the following equation by entering the correct numeric coeffici…
2 (for \(Ag_2S\)), 2 (for \(H_2O\)), 4 (for \(Ag\)), 2 (for \(H_2S\)), 1 (for \(O_2\))
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question 9 what is the concentration (in m and mass %) of the resulting…
The molarity of the solution is approximately $1.3\space M$ and the mass percentage is $5.0\%$
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question 8 how many grams of solid product will be produced from 19.04 …
13.55
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question 7 what is the percent yield if the theoretical mass was 36.74 …
\(36.88\)
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question 4 what mass of n₂o₄(g) is needed to produce 42.85 g of n₂(g) i…
\(78.20\)
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what must happen before a chemical reaction can begin? the activation e…
The activation energy must be reached.
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which statement best describes the amount of catalyst that remains at t…
The amount of catalyst is the same at the end as at the beginning of the reaction.
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a substance that influences the reaction but does not participate in th…
A. catalyst
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a student wants to create a liquid volcano. the student observes bubble…
The candy tablets being added to the drink.
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which statement best describes how a catalyst can speed up a chemical r…
The catalyst decreases the activation energy needed.
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a researcher is designing a laboratory experiment to determine whether …
B. First, he should measure how long it takes for the liquid to become clear if X and Y are mixed together. Then, he should measure how long it takes if he also adds substance A t…
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question # 4 multiple choice the pmi for remains of a body newly buried…
chemical and physical analysis of soft tissues
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quiz_-_nuclear_chemistry_(part_2)... due by friday 11:59 pm on 11/7 qui…
1. A. alpha particle 2. C. \(^{198}\text{Au}\) 3. B. a longer half - life and a different decay mode 4. B. Small amounts of matter are converted into large amounts of energy. 5. B…
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10. what is the total number of atoms of c, o and h in 0.260 mol of glu…
\(3.76\times 10^{24}\space atoms\)
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a gas mixture contains 0.150 mol of oxygen (o₂) gas, 0.419 mol of nitro…
76.3 atm
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a sample of a gas has a pressure of 1.01 atm when the volume is 256 ml.…
\(2.19\) atm (the fourth option)
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what is the temperature of a 1.59 l flask containing 0.175 mol of ne at…
\(121\space K\)
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name the compound shown below. pbo₂ lead (ii) oxide check you have corr…
Lead(IV) oxide
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a sample of a gas has a pressure of 1.01 atm when the volume is 256 ml.…
A. 2.08 atm
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name the compound shown below. pb3p2 lead (i phosphide
Lead (II) Phosphide
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a gas mixture contains 0.150 mol of oxygen (o₂) gas and 0.211 mol of ar…
A. 0.416
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how many molecules of o₂ are present in a 3.90 l flask at a temperature…
\(1.05\times 10^{23}\text{ molecules}\)
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what is the temperature of a 1.59 l flask containing 0.175 mol of ne at…
336 K
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what will happen to the pressure of a gas if its absolute temperature t…
The pressure will triple (increase by a factor of three).
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question 3 · 1 point what will happen to the volume of a gas if its abs…
The volume will triple (increase by a factor of three).
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question 2 · 1 point a sample of a gas has a pressure of 248 mm hg when…
B. \(65.4\ \text{mm Hg}\)
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match the items. a. the maximum rate of production or the maximum rate …
1. f. Unselfishly concerned for or devoted to the welfare of others. 2. a. The maximum rate of production or the maximum rate at which something can be processed. 3. g. Involving …
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write the nuclear symbol for gallium. ga blank 1: blank 2:
Blank 1: \(70\) (or \(71\)) Blank 2: \(31\)
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how do you determine the number of neutrons an element has? o a is the …
A. Is the mass number minus atomic number
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question 2 (1 point) which element would have an atomic number of 9 and…
A. Fluorine
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according to the kinetic molecular theory, where does the pressure exer…
Pressure results from collisions between the constantly moving gas molecules and the container walls.
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question which of the following statements agrees with the chemical axi…
B. Polar solutes dissolve in polar solvents. C. Non - polar solutes dissolve in non - polar solvents.
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question when considering solutions of liquids in liquids, polar liquid…
D. polar liquids
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question which of the following will increase the solubility of carbon …
C. Keeping it in the refrigerator.
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1.54 pts in piagets theory of cognitive development, accommodation occu…
changes an existing mental schema or creates a new one to include new information
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if two liquids are of moderate mutual solubility, they are said to be _…
C. partially miscible
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question which physical form(s) of matter have neither a definite volum…
plasma, gas
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question which of the following is a phase of matter? select all that a…
plasma, solid, liquid, gas
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the image below was captured over a hot mug of coffee on a cold morning…
solid, liquid, gas
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a mixture with h₂ and he exerts a total pressure of 0.48 atm. if there …
0.16 atm
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why should you wear gloves, apron, and eye protection when working with…
Battery acid can cause serious burns.
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what relates the partial pressure of a gas to the total pressure of a g…
mole fraction
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in a mixture of noble gases, neon has a mole fraction of 0.5, argon has…
neon
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the ideal gas law displays the relationship in which of the following? …
A. Amontons's law, B. Charles's law, C. Boyle's law, D. Avogadro's law
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which law can be derived from the ideal gas law? select the correct ans…
all of the above
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question what will be the volume occupied by 2.5 moles of nitrogen gas …
56 L
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question a 50.0 l container holds 45.0 moles of gas. the temperature of…
34.9 atm
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which is a correct way of stating amontonss (gay-lussacs) law? select t…
all of the above
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question if the volume of a gas is kept constant and the temperature (i…
double
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when maya started her new job at a law firm, all the procedures and ter…
schemas
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gay - lussacs law assumes that _________.(select all the are true.)sele…
the volume is held constant, the number of moles is held constant
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question the volume of a gas sample is observed to have decreased, even…
The temperature decreased
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using the \criss - cross\ method and your oxidation number chart, choos…
B. \(Ca(NO_{3})_{2}\)
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which is a correct way of stating charless law? select the correct answ…
all of the above
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a woman is writing the content for the company website of a backpack ma…
- Call our prompt and friendly customer service department with questions and feedback: Contact - I thought to myself, "I wish there were more options for boys with other interest…
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question 5 calculate the density of co₂ gas at 20°c and 860 mm hg. (co₂…
\(2.07\ g/L\)
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using the \criss - cross\ method and your oxidation number chart, choos…
For sodium and oxygen: B. \(Na_{2}O\) For calcium and nitrate: None of the options \(a\), \(b\), \(c\) are correct. The correct formula is \(Ca(NO_{3})_{2}\)
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a helium balloon has a volume of 10.2 l at -34°c and 366 mm hg. what is…
5.61 L
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to solve problems using charles law, which mathematical equation should…
\(\frac{V_1}{T_1}=\frac{V_2}{T_2}\)
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the octet rule involves elements trying to get a full outer shell of el…
1. a. TRUE 2. a. TRUE 3. c. \(Al_2O_3\)
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the air pressure in a volleyball is 75 psi. what is this pressure in to…
3900 torr
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a balloon has 1.00 l gas at sea level (1.00 atm). if the balloon is tak…
1.18
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choose the gas that has the greatest average molecular speed at 25°c. c…
He
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question under conditions of constant temperature and amount of substan…
D. none of the above
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a mixture of three gases has a total pressure of 1380 mm hg at 298 k. t…
356 mm Hg
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sort the answers below as either relating to an ionic bond or a covalen…
- **Ionic Bond**: Bond between a METAL AND NON - METAL, Bond between an element on the LEFT and the RIGHT side of the table - **Covalent Bond**: Bond between 2 NON - METALS, Bond …
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question 4 2 pts calculate the density, in g/l, of cl₂(g) at stp. 0.316…
3.16 g/L
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if a collision is said to be elastic, it means _________. select the co…
C. no kinetic energy is lost as a result of the collision
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how many molecules of nitrogen gas can be present in a 2.5 l flask at 3…
\(4.9\times 10^{22}\ molecules\) (the second option)
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a gas filled balloon with a volume of 12.5 l at 0.90 atm and 294 k is a…
\(1.0\times 10^{4}\ L\)
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according to kmt, at constant pressure and temperature, the frequency a…
Avogadro's law
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if 30.0 l of oxygen gas is cooled from 473 k to 274 k at constant press…
17.4 L
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according to kmt, if the temperature of a gas is increased, there will …
Charles's law
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why should you wear gloves, apron, and eye protection when working with…
Battery acid can cause serious burns.
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question 10 (1 point) which statement is true about phenolphthalein, th…
Phenolphthalein is colorless in acidic solution and pink in basic solution.
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what can you use to neutralize a spill of battery acid? salt. baking so…
B. Baking Soda.
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which of the following is true regarding the size of gas molecules, acc…
The size of the molecules is so small compared to the distance between them that the size is taken to be negligible.
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question 10 (1 point) which statement is true about phenolphthalein, th…
C. Phenolphthalein is colorless in acidic solution and pink in basic solution
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in the reaction, ( k_{2}so_{4}+ba(no_{3})_{2}\to baso_{4}+2kno_{3} ), w…
$\mathrm{K^+}$ and $\mathrm{NO_3^-}$ (first option)
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question 9 (1 point) in the reaction, k₂so₄ + ba(no₃)₂ → baso₄ + 2kno₃,…
$\ce{K^{+}}$ and $\ce{NO^{-}_{3}}$
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question 9 (1 point) in the reaction, k₂so₄ + ba(no₃)₂ → baso₄ + 2kno₃,…
$\ce{K^{+}}$ and $\ce{NO^{-}_{3}}$
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question 8 (1 point) what is the term for an equation that portrays hig…
A. molecular equation
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which buffer systems act in order from the fastest to the slowest? a.) …
d. Chemical, Respiratory, Renal
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which statement is correct about reading a burette? a) markings increas…
b) markings increase from top to bottom and are read based on the lower number
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question 6 (1 point) what would be the products of the following mixtur…
E. \(\mathrm{CaSO_4 + NaCl}\)
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question 5 (1 point) a stock solution is used to make a dilute solution…
\(0.018\space L\)
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question 4 (1 point) which combination of aqueous solutions should prod…
d) \(AgNO_3\) and \(Ca(CH_3COO)_2\)
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question 3 (1 point) which of the following symbols denotes a substance…
E. (aq)
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multiple - choice question what does it mean to be amphipathic? both wa…
both water loving and water fearing/hating
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which type of reaction is the following? h₂so₄(aq) + 2lioh(aq) → li₂so₄…
d) acid - base neutralization
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question 1 (1 point) what is the net ionic equation for the reaction? h…
$H^{+}+OH^{-} ightarrow H_{2}O$
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what does it mean to be hydrophilic? both water loving and water fearin…
C. water loving
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what is the net ionic equation for the reaction? h₃po₄ + 3koh → k₃po₄ +…
$\ce{H+ + OH- -> H2O}$ (Note: $\ce{H3PO4}$ is a weak acid, but in net - ionic equations for acid - base reactions, we can represent it as donating $\ce{H+}$ in a simplified sense …
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multiple - choice question what does it mean to be hydrophobic? water l…
B. water fearing or hating
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when glucose is limited, which molecule can serve as a fuel source for …
A. Ketone bodies
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what is a mosaic? small parts of a molecule a large picture made up of …
B. a large picture made up of small pieces
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8. why must absorbance readings be taken shortly after adding the dye? …
B. The color becomes unstable after 30–60 minutes